Review Revisiting the Baldwin s Rules Guidelines for Ring Closure Li Yuanhe Anion- 3/4 4/5 5/6 6/7 endo- -dig exo- endo- -trig exo- endo- -tet exo-
|
|
|
- Nancy Pearson
- 5 years ago
- Views:
Transcription
1 Review Revisiting the Baldwin s Rules Guidelines for Ring Closure Li Yuanhe Anion - 3/4 4/5 5/6 6/7 -trig Supervisors: Prof. Yang Prof. Chen -tet Prof. Tang
2 Introduction (Sir) Jack Baldwin 1938, Born, London 1960, B. Sc. Imperial College 1964, Ph. D. Imperial College, Prof. Barton 1965, Assistant Lecturer, Imperial College 1967, Assistant Prof., U. Penn. 1970, Assistant Prof., MIT 1972, Full Professor, King's College 1972, Full Professor, MIT 1978, Waynflete Professor, U. Oxford 1997, awarded a knighthood 2005, retirement Rules for ring closure 1976, definitions, basic rules. J. Chem. Soc., Chem. Commun., 1976, 734. (Cited 2393 times, second most cited paper* ) J. Chem. Soc., Chem. Commun., 1976, 736. (5-endo-trig) 1977, rule of enolates J. Chem. Soc., Chem. Commun., 1977, , application to aldol reaction Tetrahedron, 1982, 38, * Chem. Commun. the most cited paper: Chem. Commun., 1994, 801.; cited 4939 times. Method of gold nanoparticle synthesis. 2/39
3 Introduction (Sir) Jack Baldwin 1938, Born, London 1960, B. Sc. Imperial College 1964, Ph. D. Imperial College, Prof. Barton 1965, Assistant Lecturer, Imperial College 1967, Assistant Prof., U. Penn. 1970, Assistant Prof., MIT 1972, Full Professor, King's College 1972, Full Professor, MIT 1978, Waynflete Professor, U. Oxford 1997, awarded a knighthood 2005, retirement Rules for ring closure 1976, definitions, basic rules. J. Chem. Soc., Chem. Commun., 1976, 734. (Cited 2393 times, second most cited paper* ) J. Chem. Soc., Chem. Commun., 1976, 736. (5-endo-trig) 1977, rule of enolates J. Chem. Soc., Chem. Commun., 1977, , application to aldol reaction Tetrahedron, 1982, 38, * Chem. Commun. the most cited paper: Chem. Commun., 1994, 801.; cited 4939 times. Method of gold nanoparticle synthesis. 3/39
4 The Baldwin s Rules Nomenclature n - endo/exo - tet/trig/dig tetrahedron exo- trigonal digonal 3-exo 4-exo tet- 3-endo-tet 4-endo-tet 5-endo-tet 6-endo-tet 7-endo-tet endo- trig- 3-endo-trig 4-endo-trig 5-endo-trig dig- J. Baldwin* Chem. Commun, 1976, 734. R. Moriarty*, J. Org. Chem. 1985, 50, /39
5 The Baldwin s Rules Nomenclature enolate X-endo-trig 3-endo-trig 4-endo-trig 5-endo-trig exo-trig 3~5-enolendo-exo-tet 3~5-enolendo-exo-trig enolendoexo-tet X-exo-trig exo-tet enolexo- exo-trig J. Baldwin* et.al., Chem. Commun., 1977, /39
6 The Baldwin s Rules Baldwin s Explanation To be skipped Limitations (mentioned by Baldwin) Limits to kinetically controlled reaction 3/4 4/5 5/6 6/7 -trig Note: however thermodynamic factor can affect kinetic outcome. Excluded pericyclic reactions Excluded transition metal involvement In ring atoms limited to first row element (C, H, O, N ) Si, P, S : Bond Length; Orbital size; Polarizability; d-orbital H: Bond Length; s orbital; tunneling effect Calculated at B3LYP/ma-def2-SV(P) level All the same in this report if not mentioned 6/39
7 Anion -, Radical, Cation + Incoming species 7/39
8 Outline Dig- The major discrepancy Anion, Rad, Cation 3/4 4/5 5/6 6/7 Trig- The 5-endo-trig problem 3/4 4/5 5/6 6/7 -trig Tet endo/exo selectivity 3/4 4/5 5/6 6/7 -tet Enolendo / enolexo- 8/39
9 The problem Anion, Rad, Cation 3/4 4/5 5/6 6/7 Proposed by Baldwin Orbital and the acute attack angle Free attack transition state: 134 o (Propyne, myself) 132 o (Ethyne, Houk) 9/39
10 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo exo- 3-exo By Baldwin 3/4 endo- 4-endo exo- 3-exo 3-exo - vs 4-endo - (3-exo: rare, 4-endo: unprecedented) 3-exo - 4-endo - (by Reaxys general reaction search, rearrangement after 4-endo not included) J. Johnson, et. al., J. Am. Chem. Soc., 2008, 130, /39
11 4-endo - Some theoretical background Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo exo- 3-exo By Baldwin 3/4 endo- 4-endo exo- 3-exo Marcus theory Remove ΔG factor from ΔG difference NICS (Nuclear independent chemical shift) A measurement of (anti)aromaticity ( 核独立化学位移, in ppm) B ppm ppm > normal H -8.0 ppm 1 2 Obtain Intrinsic (activation) energy ΔE ΔG=0 Thermodynamic induced kinetic preference J. Am. Chem. Soc., 1996, 118, 6317; Chem. Rev., 2005, 105, /39
12 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo exo- 3-exo 4-endo - σ-(anti)aromaticity transition state By Baldwin 3/4 endo- 4-endo exo- 3-exo 3-exo σ-2e σ-aromatic 4-endo σ-4e σ-antiaromatic The energy aspect E a : activation energy E r : reaction energy E o : intrinsic energy Alabugin*, Chem. Rev. 2011, 111, /39
13 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo 5-endo exo- 3-exo 4-exo By Baldwin 4/5 endo- 5-endo exo- 4-exo 4-exo - vs 5-endo - (both rare, endo rarer) Bare cases 4-exo J. Am. Chem. Soc. 1993, 115, J. Org. Chem. 1993, 58, Tune by: Aromaticity (thermodynamic induced kinetic preference) J. Org. Chem. 1986, 51, Chem. Eur. J. 2009, 15, 838.
14 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo 5-endo exo- 3-exo 4-exo By Baldwin 4/5 endo- 5-endo exo- 4-exo 4-exo - vs 5-endo - (both rare, endo rarer) Tune by: Bond Polarity MO of difference substrate HOMO α-c 26% β-c 52% LUMO α-c 9.5% β-c 5.1% (mixed with O-H) HOMO α-c 7.1% β-c 0.8% (mixed with O-LP) LOMO α-c 5.6% β-c 27% 14/39
15 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo 5-endo exo- 3-exo 4-exo By Baldwin 4/5 endo- 5-endo exo- 4-exo 4-exo - vs 5-endo - (both rare, endo rarer) Tune by: Bond Polarity Chem.Eur. J. 2009, 15, 838. Substrate constrain J. Am. Chem. Soc. 1993, 115, Tetrahedron Lett. 1986, 27, /39
16 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo By Baldwin 5/6 endo- 6-endo exo- 5-exo 5-exo - vs 6-endo - (both common, exo easier) Energy aspect Default exo Tetrahedron Lett. 1998, 39, Tetrahedron Lett. 1990, 31, 493. 张力 ensure Myers, et. al., J. Am. Chem. Soc. 2007, 129, /39
17 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo By Baldwin 5/6 endo- 6-endo exo- 5-exo 5-exo - vs 6-endo - (both common, exo easier) Generation of stabilized anion Bond polarity Linker dependent Elimination directed Tetrahedron Lett. 2002, 43, 9187; Heterocycles 2002, 57, endo & 6-exo not observed in this system 17/39
18 Anion - dig cyclization Anion - 3/4 4/5 5/6 6/7 By Baldwin 6/7 endo- 7-endo exo- 6-exo 6-exo - vs 7-endo - (6-exo common, (pure) 7-endo rare, Assisted 7-endo common) R. Dillard, N. Easton, J. Org. Chem., 1966, 31, 122.; B. Taylor*, Tetrahedron Lett., 1997, 38, B. Kundu*, J. Org. Chem. 2011, 76, /39
19 Anion - dig cyclization Baldwin: Anion, Cation, Rad. 3/4 4/5 5/6 6/7 Search result: Anion - 3/4 4/5 5/6 6/7 19/39
20 Cation + dig cyclization Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo The instability of in-ring vinyl cation HOMO (π) LUMO (LP*) LUMO+1 (π*) HOMO (π) LUMO (LP*) LUMO+1 (π*) 20/39
21 Cation + dig cyclization Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo 4-endo + vs 3-exo + (4-endo very rare (if any), 3-exo unprecedented) Fake 4-endo + : NPEC (Nucleophile-Promoted Electrophilic Cyclization) 5-endo + vs 4-exo + (Both unprecedented) Hanack, M. et. al., Tetrahedron Lett. 1968, 44, Hanack, M. et. al., Angew. Chem., Int. Ed. 1978, 17, /39
22 Cation + dig cyclization Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo 6-endo + vs 5-exo + (Both very common, subtle control) J. Org. Chem. 1992, 57, 883. J. Am. Chem. Soc. 1969, 90, Chem. Commun. 1990, /39
23 Outline Dig- The major discrepancy Anion - 3/4 4/5 5/6 6/7 Trig- The 5-endo-trig problem 3/4 4/5 5/6 6/7 -trig Tet endo/exo selectivity 3/4 4/5 5/6 6/7 -tet Enolendo / enolexo- 23/39
24 Anion - Trig= cyclization 3/4 4/5 5/6 6/7 -trig Anion-trig attack The endo difficulty Planer: No orbital overlap Stereoelectronic required distortsion HOMO-LUMO orbital recombination ( overlap ): 24/39
25 Anion - Trig= cyclization 3/4 4/5 5/6 6/7 -trig By Baldwin 3/4 endo- 4-endo -trig exo- 3-exo 3-exo-trig - vs 4-endo-trig - (Both unprecedented) Only indirect 4-endo-trig reported 4-exo ~ 7-exo common G. Rousseau*, J. Org. Chem. 1999, 64, /39
26 Anion - Trig= cyclization 3/4 4/5 5/6 6/7 -trig 5-endo-trig Anion stabilization at attacked endo position Oxonium / iminium J. Am. Chem. Soc, 1995, 117, 6394 Tetrahedron Lett.,1985, 26, J. Am. Chem. Soc,, 2005, 127, J. Org. Chem., 1990, 55, /39
27 Outline Dig- The major discrepancy Anion - 3/4 4/5 5/6 6/7 Trig- The 5-endo-trig problem 3/4 4/5 5/6 6/7 -trig Tet endo/exo selectivity 3/4 4/5 5/6 6/7 -tet Enolendo / enolexo- 27/39
28 Anion - tet cyclization 3/4 4/5 5/6 6/7 -tet By Baldwin 3/4 6/7 endo- 4-endo 7-endo -tet exo- 3-exo 6-exo endo-tet vs exo-tet (-exo always win) Misuse of nomenclature X-endo-tet for epoxide endo-tet is not a cyclization process only for completeness Baldwin 28/39
29 Anion - tet cyclization Misuse of nomenclature X-endo-tet for epoxide Countless (important) papers misuse the endo-tet (said Chem. Commun., 2013, 49, 11246) Kinya Hotta*, Xi Chen*, et. al., Nature, 2012, 483, /39
30 Anion - tet cyclization Misuse of nomenclature X-endo-tet for epoxide Countless (important) papers misuse the endo-tet Nature doesn t work against stereoelectronic principles; Nature chooses by giving an additional advantage to one of the two favorable processes. Chem. Commun., 2013, 49, Kinya Hotta*, Xi Chen*, et. al., Nature, 2012, 483, /39
31 Anion - tet cyclization 3/4 4/5 5/6 6/7 -tet Small-ring endo-tet almost always impossible Eschenmoser, et. al., Helvetica Chimica Acta, 1970, 53, /39
32 Anion - tet cyclization 3/4 4/5 5/6 6/7 -tet Small-ring endo-tet almost always impossible By Baldwin 3/4 6/7 -tet endo- 4-endo 7-endo exo- 3-exo 6-exo orbital of 6-exo-tet TS Is the mechanism of S N 2 reaction really that simple? Direct S N 2 mechanisms By crossed molecular beam exp. & quantum dynamic calculation Jing Xie, William L. Hase, Science, 2016, 352, /39
33 Anion - tet cyclization 3/4 4/5 5/6 6/7 -tet By Baldwin 3/4 6/7 endo- 4-endo 7-endo -tet exo- 3-exo 6-exo Is the mechanism of S N 2 reaction really that simple? Other indirect S N 2 pathway Jing Xie, William L. Hase, Science, 2016, 352, /39
34 Anion - tet cyclization 3/4 4/5 5/6 6/7 -tet Endo/exo selectivity of exo-tet reaction (default exo, endo tunable) Stabilized partial charge Nicolaou, et.al., Chem. Commun., 1985, 1359.; J. Am. Chem. Soc., 1989, 111, /39
35 Anion - tet cyclization Endo/exo selectivity of exo-tet reaction (default exo, endo tunable) Destabilized partial positive charge Reagent controlled Chem. Eur. J.; 1997, 3, 849. Derived from other species Angew. Chem. Int. Ed. 2006, 45, 810. J. Org. Chem., 2013, 78, 872. Tetrahedron Lett., 1994, 35, /39
36 Outline Dig- The major discrepancy Anion - 3/4 4/5 5/6 6/7 Trig- The 5-endo-trig problem 3/4 4/5 5/6 6/7 -trig Tet endo/exo selectivity 3/4 4/5 5/6 6/7 -tet Enolendo / enolexo- 36/39
37 Enolendo- / enolexo exo- enolendo- 3-enolendo -exo-tet/trig 4-enolendo -exo-tet/trig 5-enolendo -exo-tet/trig 6-enolendo -exo-tet/trig exo- enolexo- 3-enolexo -exo-tet/trig 4-enolexo -exo-tet/trig 5-enolexo -exo-tet/trig 6-enolexo -exo-tet/trig 3-enolendo Mechanism of Favorskii Rearrangement 5/6-enolendo Not applicable on oxonium / iminium Loose molecular orbital (?!) J. Am. Chem. Soc,, 2005, 127, /39
38 Summary Anion - 3/4 4/5 5/6 6/7 Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo exo- 3-exo 4-exo 5-exo Anion - 3/4 4/5 5/6 6/7 -trig Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo -trig exo- 3-exo 4-exo 5-exo Anion - 3/4 4/5 5/6 6/7 -tet Cation + 3/4 4/5 5/6 endo- 4-endo 5-endo 6-endo -tet exo- 3-exo 4-exo 5-exo exo- enolendo- 3-enolendo -exo-tet/trig 4-enolendo -exo-tet/trig 5-enolendo -exo-tet/trig 6-enolendo -exo-tet/trig exo- enolexo- 3-enolexo -exo-tet/trig 4-enolexo -exo-tet/trig 5-enolexo -exo-tet/trig 6-enolexo -exo-tet/trig Radical: 3,4-endo/exo-trig/dig: rare; 5,6-trig/dig: favor exo 38/39
39 Recommended Reviews (not in order) Alabugin*, et. al., Chem. Commun., 2013, 49, Zeni*, et. al., Chem. Rev. 2011, 111, Alabugin*, Chem. Rev. 2011, 111, Sarah Wengryniuk, Breaking the Rules: "Anti-Baldwin" Cyclizations, Baran Group Meeting Alabugin*, et. al., J. Am. Chem. Soc. 2011, 133, X Jiang and H Liu, 4.07: Electrophilic Cyclization, Comprehensive Organic Synthesis II, Volume 4 Radical(not covered): The book, Chapter 11, Free Radical Reactions Hideo Togo, Advanced Free Radical Reactions for Organic Synthesis Dowd*, et. al., Chem. Rev. 1993, 93, Uta Wille*, Chem. Rev. 2013, 113, /39
40 Acknowledgements Prof. Yang, Prof. Chen, Prof. Tang Mr. Liu Dong-Dong B630 Everyone in Lab. and everyone here Ac 40/39
3. The ring being formed has six members; the breaking C C bond is inside the new ring (endo); the C being attacked is a digonal (sp) atom (dig)
0. aturated heterocycles and stereoelectronics xyanions add readily to alkynes: see Chapter, p. 000. Br Because the same arguments apply to o for the reaction as a whole (the difference in entropy between
Cyclizations of Alkynes: Revisiting Baldwin s Rules for Ring Closure
pubs.acs.org/cr Cyclizations of Alkynes: Revisiting Baldwin s Rules for Ring Closure Kerry Gilmore and Igor V. Alabugin* Department of Chemistry and Biochemistry, Florida State University, Tallahassee,
A Simple Introduction of the Mizoroki-Heck Reaction
A Simple Introduction of the Mizoroki-Heck Reaction Reporter: Supervisor: Zhe Niu Prof. Yang Prof. Chen Prof. Tang 2016/2/3 Content Introduction Intermolecular Mizoroki-Heck Reaction Intramolecular Mizoroki-Heck
Radical Reactions. Radical Stability!!! bond dissociation energies X Y X + Y. bond BDE (kcal/mol) bond BDE (kcal/mol) CH 3 CH 3 CH 2 95 O H R 2 C H
adical eactions adical Stability!!! bond dissociation energies X Y X Y bond BDE (kcal/mol) bond BDE (kcal/mol) C 3 104 108 C 3 C 2 98 110 95 2 C 102 (-) 93 (C-) 92 C 3 C 3 36 89 85 C 3 C 3 80 adical eactions
Synthesis, Mechanism, and Properties of Cyclopenta-fused Polycyclic Aromatic Hydrocarbons. Chaolumen. Introduction
March 22, 2018 Synthesis, Mechanism, and Properties of Cyclopenta-fused Polycyclic Aromatic Hydrocarbons Reaxys Prize Club Symposium in Japan 2018 Chaolumen Institute for Chemical Research, Kyoto University
Loudon Chapter 15 Review: Dienes and Aromaticity Jacquie Richardson, CU Boulder Last updated 1/28/2019
This chapter looks at the behavior of carbon-carbon double bonds when several of them are in the same molecule. There are several possible ways they can be grouped. Conjugated dienes have a continuous
ELECTRON FLOW IN ORGANIC CHEMISTR Y. Paul H. Scudder
ELECTRON FLOW IN ORGANIC CHEMISTR Y Paul H. Scudder 1 BONDING AND ELECTRON DISTRIBUTION 1 2 THE PROCESS OF BOND FORMATION 3 4 3 STABILITY AND REACTIVITY OF INTERMEDIATES 5 6 4 CLASSIFICATION OF ELECTRON
Synthetically useful extrusion reactions in organic chemistry
Synthetically useful extrusion reactions in organic chemistry Reporter: Sun Baochuan Supervisors: Prof. Yang Zhen Prof. Chen Jiahua Extrusion Reactions Extrusion Reaction: An atom or group Y connected
Grob Fr agmentations. Dan Tao Overman Group Meeting 9/24/12
: Grob Fr agmentations Dan Tao Overman Group Meeting 9/24/12 What is a Grob Fragmentation? Heterolytic fragmentation is certain combinations of carbon and hetero atoms which undergo a regulated cleavage
C H activation of aliphatic amines without unnecessary mask M2 Takaya Togo
C H activation of aliphatic amines without unnecessary mask 2017.11.25 M2 Takaya Togo 1 Outline 1.Introduction 2.Free amines as DG Discovery of new activation mode Mechanistic studies Application of the
sp 3 C-H insertion by α-oxo Gold Carbene B4 Kei Ito
1 sp 3 C-H insertion by α-oxo Gold Carbene B4 Kei Ito 2016. 1. 30 1. Introduction 2 About Carbene 3 Brief history of carbene (~2000) Carbene Neutral compounds featuring a divalent carbon atom with only
Selectivity and Natural Product Synthesis. Reporter: Liang Xin-ting Supervisors: Prof. Yang Prof. Chen Prof. Tang
Selectivity and Natural Product Synthesis Reporter: Liang Xin-ting Supervisors: Prof. Yang Prof. Chen Prof. Tang Content Introduction Selectivity of oxidative coupling Chemoselectivity Regioselectivity
STEREOCHEMISTRY AND STEREOELECTRONICS NOTES
- 1 - STEREOCHEMISTRY AND STEREOELECTRONICS NOTES Stereochemistry in Organic Molecules Conventions used in drawing molecules Also, Fischer projections can sometimes be useful for acyclic molecules with
Chemistry III (Organic): An Introduction to Reaction Stereoelectronics. LECTURE 1 Recap of Key Stereoelectronic Principles
1 Chemistry III (Organic): An Introduction to Reaction Stereoelectronics LCTUR 1 Recap of Key Stereoelectronic Principles Alan C. Spivey a.c.spivey@imperial.ac.uk Nov 2015 2 Format & scope of lecture 1
Review. Recent Developments in Pd-catalyzed Carbonylation Reaction. Li Yuanhe. Supervisors: Prof. Yang Prof. Chen Prof. Tang
Review Recent Developments in Pd-catalyzed Carbonylation Reaction Li Yuanhe Supervisors: Prof. Yang Prof. Chen Prof. Tang History 1962, E. Fischer Z. Nafurforsch. 1962, 17b, 484. 1963, R. Heck J. Org.
Conjugated Systems, Orbital Symmetry and UV Spectroscopy
Conjugated Systems, Orbital Symmetry and UV Spectroscopy Introduction There are several possible arrangements for a molecule which contains two double bonds (diene): Isolated: (two or more single bonds
STEREOELECTRONIC EFFECTS (S.E.) IN ORGANIC CHEMISTRY
STEREOELECTRONIC EFFECTS (S.E.) IN ORGANIC CHEMISTRY Pierre Deslongchamps (version du 16 février 2010) Cf. pour le livre: http://pages.usherbrooke.ca/pdeslongchamps/cv.htm 1 SECTION 8 Stereoelectronic
Ring constructions by the use of fluorine substituent as activator and controller*
Pure Appl. Chem., Vol. 72, No. 9, pp. 1685 1689, 2000. 2000 IUPAC Ring constructions by the use of fluorine substituent as activator and controller* Junji Ichikawa Department of Chemistry, Graduate School
Chemistry 610: Organic Reactions Fall 2017
Instructor Prof. David Powers Office: Chemistry 320 Phone: 979.862.3089 E-mail: david.powers@chem.tamu.edu Learning Outcomes Chemistry 610: Organic Reactions Fall 2017 Tuesday and Thursday 2:20 3:35 PM
Problem Set 2: Reactions of Carbocations - KEY
Problem Set 2: eactions of Carbocations - KEY Due Tuesday, 10/11/16 1. a. Formation of 1 and 2 silyl ethers is always high-yielding, but selective silylation of a single hydroxyl group can be challenging.
Metalloporphyrin. ~as efficient Lewis acid catalysts with a unique reaction-field~ and. ~Synthetic study toward complex metalloporphyrins~
Metalloporphyrin ~as efficient Lewis acid catalysts with a unique reaction-field~ and ~Synthetic study toward complex metalloporphyrins~ Literature Seminar Kenta Saito (D1) 1 Topics Chapter 1 ~as efficient
Pericyclic reactions
Pericyclic reactions In pericyclic reactions the breaking and making of bonds occur simultaneously by the way of a single cyclic transition state (concerted reaction). There are no intermediates formed
Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang!
1! Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang! 2! utline! 1. Brief Introduction! 2. ucleophilic Dominoes! 3. Electrophilc Dominoes! 4. Radical
Amphoteric Molecules < Chemistry of Andrei K. Yudin > Hyung Min Chi 17 JUNE 2014
Amphoteric Molecules < Chemistry of Andrei K. Yudin > Hyung Min Chi 17 JUNE 2014 1 Amphoteric molecules Amphoteric? Greek word amphoteros (both of two) Amphoterism in acid/base chemistry Amino acids (thermodynatic
C H Activated Trifluoromethylation
Literature report C H Activated Trifluoromethylation Reporter:Yan Fang Superior:Prof. Yong Huang Jun. 17 th 2013 Contents Background Trifluoromethylation of sp-hybridized C-H Bonds Trifluoromethylation
Ethers. Chapter 14: Ethers, Epoxides, & Sulfides. General Formula: Types: a) Symmetrical: Examples: b) Unsymmetrical: Examples: Physical Properties:
Chamras Chemistry 106 Lecture Notes Examination 1 Materials Chapter 14: Ethers, Epoxides, & Sulfides Ethers General Formula: Types: a) Symmetrical: Examples: b) Unsymmetrical: Examples: Physical Properties:
N-Heterocyclic Carbenes
N-Heterocyclic Carbenes References 1. "N-Heterocyclic Carbenes as Organocatalysts." Marion, N.; Diez- Gonzalez, S.; Nolan, S.P. Angew. Chem. Int. Ed. 2007, 26, 2988. (general review) 2. "Stable Carbenes."
Chiral Supramolecular Catalyst for Asymmetric Reaction
Chiral Supramolecular Catalyst for Asymmetric Reaction 2017/1/21 (Sat.) Literature Seminar Taiki Fujita (B4) 1 Introduction Rational design of chiral ligands remains very difficult. Conventional chiral
Spring Term 2012 Dr. Williams (309 Zurn, ex 2386)
Chemistry 242 Organic Chemistry II Spring Term 2012 Dr. Williams (309 Zurn, ex 2386) Web Page: http://math.mercyhurst.edu/~jwilliams/ jwilliams@mercyhurst.edu (or just visit Department web site and look
Real life example 1 Let s look at this series of chloroalcohols, and how fast the chloride gets displaced by an external nucleophile.
Class 2 Carbocations Last time we talked about neighboring group participation in substitution reactions. I want to start today by talking about a few more real life examples. Real life example 1 Let s
Igor Alabugin, Florida State University. Зимняя конференция молодых ученых по органической химии, January 20, 2015, Krasnovidovo
Stereoelectronic effects on stability and reactivity of organic molecules: from control of molecular conformations to faster cycloadditions and cyclizations Igor Alabugin, Florida State University Зимняя
Advanced Organic Chemistry
D. A. Evans, G. Lalic Chem 530A Chemistry 530A Advanced Organic Chemistry Lecture notes part 8 Carbanions Organolithium and Grignard reagents Organocopper reagents 1. Direct metalation 2. From radical
CHEMISTRY 332 FALL 08 EXAM II October 22-23, 2008
First Three Letters of Last Name NAME Network ID CHEMISTRY 332 FALL 08 EXAM II October 22-23, 2008 The following materials are permissible during the exam: molecular model kits, course notes (printed,
4.MeOTf,DCM,76% 5.1-B,MeCN,50 C,89% 6.Oxone,MeCN/H 2 O,0 C,67% 7.PIFA,DCM,rt; TFA/H 2 O(3/1),55 C,26%
Problem Session 1 Please fill in the blank and provide each reaction mechanisms. 2018. 1. 11. Akira Tomiyama 1 1-1 1.1-A,i-Pr 2 Et(excess),DCM,-78 C; then1-1,dcm,-78 C,57% 2. 2,aneyi,;DMP,DCM,69% 3.TMSTf,Et
Conjugated Systems. With conjugated double bonds resonance structures can be drawn
Conjugated Systems Double bonds in conjugation behave differently than isolated double bonds With conjugated double bonds resonance structures can be drawn With isolated double bonds cannot draw resonance
17.1 Classes of Dienes
W 2/1 Due: HW14, spec03 Due: n/a M 2/6 Lecture HW14 grading Lect17a Conjugated π systems Lecture quiz Lect17b Lab Lab02 Qual Analysis II (cont) 7-1 17.1 Classes of Dienes There are three categories for
ORGANIC CHEMISTRY. Fifth Edition. Stanley H. Pine
ORGANIC CHEMISTRY Fifth Edition Stanley H. Pine Professor of Chemistry California State University, Los Angeles McGraw-Hill, Inc. New York St. Louis San Francisco Auckland Bogota Caracas Lisbon London
Advanced Organic Chemistry
D. A. Evans, G. Lalic Question of the day: Chemistry 530A TBS Me 2 C Me toluene, 130 C 70% TBS C 2 Me H H Advanced rganic Chemistry Me Lecture 16 Cycloaddition Reactions Diels _ Alder Reaction Photochemical
σ Bonded ligands: Transition Metal Alkyls and Hydrides
σ Bonded ligands: Transition Metal Alkyls and Hydrides Simplest of organo-transitionmetal species Rare until and understanding of their stability in the 60 s and 70 s Metal alkyls can be considered as
17.1 Classes of Dienes
17.1 Classes of Dienes There are three categories for dienes: Cumulated: pi bonds are adjacent. Conjugated: pi bonds are separated by exactly ONE single bond. Isolated: pi bonds are separated by any distance
Organic Chemistry: CHEM2322
Conjugated Systems Organic Chemistry: We met in Chem 2321 unsaturated bonds as either a C=C bond or C C bond. If these unsaturated bonds are well separated then they react independently however if there
S N 1 Displacement Reactions
S N 1 Displacement Reactions Tertiary alkyl halides cannot undergo S N 2 reactions because of the severe steric hindrance blocking a backside approach of the nucleophile. They can, however, react via an
Suggested solutions for Chapter 31
s for Chapter 31 31 PRBLEM 1 Predict the most favourable conformation for these insect pheromones. Practice drawing the conformations of cyclic acetals. There are many good ways to draw these conformations
EASTERN ARIZONA COLLEGE General Organic Chemistry I
EASTERN ARIZONA COLLEGE General Organic Chemistry I Course Design 2015-2016 Course Information Division Science Course Number CHM 235 (SUN# CHM 2235) Title General Organic Chemistry I Credits 4 Developed
RESEARCH REPOSITORY.
RESEARCH REPSITRY This is the author s final version of the work, as accepted for publication following peer review but without the publisher s layout or pagination. The definitive version is available
Protecing-Group-Free Synthesis. Reporter: Zhu Zhiyang Advisor: Prof Yang Prof Chen Prof Tang Date:
Protecing-Group-Free Synthesis Reporter: Zhu Zhiyang Advisor: Prof Yang Prof Chen Prof Tang Date: 2015.05.19 1 Outline Introduction Protecting-Group-Free Synthesis Historic Background Strategies & examples
Chem 634. Pericyclic Reactions. Reading: CS-B Chapter 6 Grossman Chapter 4
Chem 634 Pericyclic eactions eading: CS-B Chapter 6 Grossman Chapter 4 Pericyclic eactions Definition: Continuous, concerted reorganization of electrons cyclic transition state no intermediate, single
Cambrian Explosion, Complex Eukaryotic Organism, Ozonosphere 3
Reporter: Wang Yuefan Reporter: Wang Yuefan Supervisor: Prof. Yang Zhen Supervisor: Prof. Yang Zhen Prof. Chen Jiahua Prof. Chen Jiahua 1 2011-12-2727 2011-02 2012-03 02-25 03-23 25 Content Preface Nature
Total Synthesis of (+)-Gelsemine. Xuan Dong group seminar 12/19/2012
Total Synthesis of (+)-Gelsemine Xuan Dong group seminar 12/19/2012 Historical Background of Gelsemine First detected the presence of alk aloids in extracts of G. sempervir ens in 1870 by Wormley. 1876,
Chemistry 12B Organic Chemistry. Spring 2016
Chemistry 12B Organic Chemistry Spring 2016 Instructor: Nada Khouderchah E-mail: khouderchahnada@fhda.edu Office hours and location: Tuesday from 5:00-5:50 pm and Thursday from 7:20 8:20 pm in the faculty
Module 10 : Reaction mechanism. Lecture 1 : Oxidative addition and Reductive elimination. Objectives. In this lecture you will learn the following
Module 10 : Reaction mechanism Lecture 1 : Oxidative addition and Reductive elimination Objectives In this lecture you will learn the following The oxidative addition reactions. The reductive elimination
A. Loupy, B.Tchoubar. Salt Effects in Organic and Organometallic Chemistry
A. Loupy, B.Tchoubar Salt Effects in Organic and Organometallic Chemistry 1 Introduction - Classification of Specific Salt Effects 1 1.1 Specific Salt Effects Involving the Salt's Lewis Acid or Base Character
Hirsutene and Δ 9(12) Capnellene. D. P. Curran (1986) Presenter: Mehdi Moemeni
irsutene and Δ 9(12) Capnellene D. P. Curran (1986) Presenter: Mehdi Moemeni Back Ground of Radical Structure In a modern context the first organic free radical identified was triphenylmethyl radical.
Oxidative Addition/Reductive Elimination 1. Oxidative Addition
Oxidative Addition Oxidative Addition/Reductive Elimination 1 An oxidative addition reaction is one in which (usually) a neutral ligand adds to a metal center and in doing so oxidizes the metal, typically
Reaction mechanisms offer us insights into how reactions work / how molecules react with one another.
Introduction 1) Lewis Structures 2) Representing Organic Structures 3) Geometry and Hybridization 4) Electronegativities and Dipoles 5) Resonance Structures (a) Drawing Them (b) Rules for Resonance 6)
1. Theoretical Investigation of Mechanisms and Stereoselectivities of Synthetic Organic Reactions
1. Theoretical Investigation of Mechanisms and Stereoselectivities of Synthetic Organic Reactions 2. Copper Catalyzed One-Pot Synthesis of Multisubstituted Quinolinones Hao Wang Denmark Group Presentation
Andrew Zahrt Denmark Group Meeting
Andrew Zahrt Denmark Group Meeting 4.28.15 Introduction Early Publications/Hypotheses: Thermodynamic Product Stability Ground State Destabilization Transition State Stabilization Solvent Effects Gas Phase
The Career of Tristan H. Lambert
The Career of Tristan H. Lambert Jian Rong( 荣健 ) Hu Group Meeting Apr 11, 2016 Tristan H. Lambert: Biographical Notes Professional experience 2011-present: Associate Professor, Columbia University 2006-2011:
Lecture Notes Chem 51C S. King Chapter 24 Carbonyl Condensation Reactions
Lecture Notes Chem 51C S. King Chapter 24 Carbonyl Condensation Reactions I. Reaction of Enols & Enolates with ther Carbonyls Enols and enolates are electron rich nucleophiles that react with a number
Self-stable Electrophilic Reagents for Trifluoromethylthiolation. Reporter: Linrui Zhang Supervisor: Prof. Yong Huang Date:
Self-stable Electrophilic Reagents for Trifluoromethylthiolation Reporter: Linrui Zhang Supervisor: Prof. Yong Huang Date: 2017-12-25 Content Introduction Trifluoromethanesulfenates: Preparation and reactivity
Chapter 27 Pericyclic Reactions
Instructor Supplemental Solutions to Problems 2010 Roberts and Company Publishers Chapter 27 Pericyclic Reactions Solutions to In-Text Problems 27.1 (b) This is a sigmatropic reaction; two electrons are
Reactivity in Organic Chemistry. Mid term test October 31 st 2011, 9:30-12:30. Problem 1 (25p)
eactivity in rganic Chemistry Mid term test ctober 31 st 2011, 9:30-12:30 Problem 1 (25p) - (+)- Limonone can be epoxidized (using peracetic acid) to give an inseparable mixture of two diastereomeric limonene
ORGANIC - BROWN 8E CH DIENES, CONJUGATED SYSTEMS, AND PERICYCLIC REACTIONS
!! www.clutchprep.com CONCEPT: INTRODUCTION TO CONJUGATION Conjugation exists when three or more atoms with the ability to resonate are adjacent to each other (overlapping). Conjugation provides an electron
and Ultraviolet Spectroscopy
Organic Chemistry, 7 th Edition L. G. Wade, Jr. Chapter 15 Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy 2010, Prentice all Conjugated Systems Conjugated double bonds are separated
*Assignments could be reversed. *
Name Key 5 W-Exam No. Page I. (6 points) Identify the indicated pairs of hydrogens in each of the following compounds as (i) homotopic, (ii) enantiotopic, or (iii) diastereotopic s. Write the answers as
Asymmetric Catalysis by Lewis Acids and Amines
Asymmetric Catalysis by Lewis Acids and Amines Asymmetric Lewis acid catalysis - Chiral (bisooxazoline) copper (II) complexes - Monodentate Lewis acids: the formyl -bond Amine catalysed reactions Asymmetric
Halogen Bond Applications in Organic Synthesis. Literature Seminar 2018/7/14 M1 Katsuya Maruyama
Halogen Bond Applications in Organic Synthesis Literature Seminar 2018/7/14 M1 Katsuya Maruyama 1 Contents 1. Introduction 2. Property of Halogen Bond 3. Application to Organic Synthesis 2 1. Introduction
AN INTRODUCTION TO MOLECULAR ORBITALS
AN INTRODUCTION TO MOLECULAR ORBITALS by YVES JEAN and FRANCOIS VOLATRON translated and edited by Jeremy Burdett New York Oxford OXFORD UNIVERSITY PRESS 1993 Contents Introduction, xiii I INTRODUCTION
This syllabus is printed on both sides of each page in the hard-copy version.
TO: FROM: Prospective Chemistry 5511 Students Peter Gaspar August 13, 2010 SUBJECT: Course Syllabus for Chemistry 5511 Fall 2010 Chemistry 5511 Mechanistic Organic Chemistry is the first semester of a
Synthesis of Polymers Prof. Paula Hammond Lecture 19: Metallocene Chemistry, Intro to New Developments from Brookhart, Others H H
10.569 Synthesis of Polymers Prof. Paula ammond Lecture 19: Metallocene Chemistry, Intro to ew Developments from Brookhart, thers Ionic Polymerization 1. Anionic 2. Cationic Anionic Polymerization - very
JEFFERSON COLLEGE COURSE SYLLABUS CHM201 ORGANIC CHEMISTRY II. 5 Credit Hours. Prepared by: Richard A. Pierce
JEFFERSON COLLEGE COURSE SYLLABUS CHM201 ORGANIC CHEMISTRY II 5 Credit Hours Prepared by: Richard A. Pierce Revised Date: January 2008 by Ryan H. Groeneman Arts & Science Education Dr. Mindy Selsor, Dean
CHEM 344 Molecular Modeling
CHEM 344 Molecular Modeling The Use of Computational Chemistry to Support Experimental Organic Chemistry Part 1: Molecular Orbital Theory, Hybridization, & Formal Charge * all calculation data obtained
Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320
Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320 I. Isolated, cumulated, and conjugated dienes A diene is any compound with two or C=C's is a diene. Compounds containing more than two
Some questions and answers that we will get out of this example synthesis:
UTLINE 535 LECTURE 3 (2004) Page 22 The Synthesis of Cubane I am showing you this synthesis because it is elegant and exemplifies many different concepts. We can use it to talk in context about the philosophical
Molecular body vs. molecular skeleton Ideal surface 1, 29
Subject Index Acid catalysis 244, 245, 247, 249, 252 Bonds-pairs 177, 178, 184, 185, 190, 191, Activation 207, 208 202-204 Activation barrier 160, 233, 242, 249 Bottleneck 291, 299, 307, 323-325, 336,
DEPARTMENT: Chemistry
CODE CHEM 204 TITLE: Organic Chemistry II INSTITUTE: STEM DEPARTMENT: Chemistry COURSE DESCRIPTION: A continuation of CHEM-203, students will extend their studies into topics including aromatic hydrocarbons,
Review. Frank Glorius & His Rh(III) C-H Activation. Li Yuanhe. Supervisors: Prof. Yang Prof. Chen Prof. Tang Prof. Luo 1 /21
Review Frank Glorius & His Rh(III) C-H Activation Li Yuanhe Supervisors: Prof. Yang Prof. Chen Prof. Tang Prof. Luo 1 /21 Author Introduction Prof. Dr. Frank Glorius 1972 Born 1991-1992 Military service
Exam. Name. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following statements is incorrect about benzene? 1) A) All of the carbon
SECTION 3. Antiperiplanar Hypothesis. and Reactions at Unsaturated Systems
SECTION 3 Antiperiplanar Hypothesis and Reactions at Unsaturated Systems (2016) 1 Reaction on Sp 2 Type Unsaturated System In cyclic ketone, both processes lead to a chair but we will see that C-H and
Recent Developments in Alkynylation
--New approaches to introduce an alkynyl group Reporter: Zhao-feng Wang Supervisor: Yong Huang 2013-03-27 Contents 1. Introduction of Acetylene Chemistry 2. Nucleophilic alkynylation : Classic text book
CHEM 330. Topics Discussed on Oct 5. Irreversible nature of the reaction of carbonyl enolates with the electrophiles discussed on Oct 2
CEM 330 Topics Discussed on ct 5 Irreversible nature of the reaction of carbonyl enolates with the electrophiles discussed on ct 2 Kinetic control in an irreversible reaction: the product that is obtained
Total Synthesis of Verruculogen and Fumitremorgin A Enabled by Ligand-Controlled C H Borylation
Enabled by Ligand-Controlled C H Borylation Yu Feng, Dane Holte, Jochen Zoller, Shigenobu Umemiya, Leah R. Simke, and Phil S. Baran J. Am. Chem. Soc. 2015, 137, 10160 10163. I. Introduction II. Retrosynthetic
Some Arrow-Pushing Guidelines (Section 1.14) 1. Arrows follow electron movement.
Chem 350 Jasperse Ch. 1 Notes 1 Note: The headers and associated chapters don t actually jive with the textbook we are using this summer. But otherwise this highlights a lot of the chemistry from Organic
Pericyclic Reactions - Continued
Dr. P. Wipf Page 1 of 7 10/21/2009 Pericyclic eactions - Continued Sigmatropic earrangements Definition: A sigmatropic rearrangement is defined as an intramolecular rearrangement of a σ bond, adjacent
Stereoselective Organic Synthesis
Stereoselective rganic Synthesis Prabhat Arya Professor and Leader, Chemical Biology Program Dean, Academic Affairs, Institute of Life Sciences (An Associate Institute of University of yderabad Supported
Iron Catalysed Coupling Reactions
LONG LITERATURE REPORT Iron Catalysed Coupling Reactions Mingyu Liu 2017. 8. 31 1 Fe [Ar]3d 6 4s 2 The fourth most common element in the Earth s crust Relatively less understanding and manipulation of
Glendale Community College Chemistry 105 Exam. 3 Lecture Notes Chapters 6 & 7
Sevada Chamras, Ph.D. Glendale Community College Chemistry 105 Exam. 3 Lecture Notes Chapters 6 & 7 Description: Examples: 3 Major Types of Organic Halides: 1. Alkyl Halides: Chapter 6 (Part 1/2) : Alkyl
David W.C. MacMillan: Career-in-Review. Yan Xu Dong Group Meeting Jan. 2, 2014
David W.C. MacMillan: Career-in-Review Yan Xu Dong Group Meeting Jan. 2, 2014 David W.C. MacMillan: A Brief Introduction Career 1968 Born in Bellshill, Scotland. 1987-1991 Undergraduate degree in chemistry
Aza-Wacker-Type Cyclization. Group Meeting Tuesday, April 19, 2011 William Kuester
Aza-Wacker-Type Cyclization Group Meeting Tuesday, April 19, 2011 William Kuester N-heterocylization Reductive Amination Hydroamination Oxidative Cyclization Chemler, S.R. Org. Biomol. Chem. 2009, 7, 3009-3019.
Lecture Notes Chem 51B S. King I. Conjugation
Lecture Notes Chem 51B S. King Chapter 16 Conjugation, Resonance, and Dienes I. Conjugation Conjugation occurs whenever p-orbitals can overlap on three or more adjacent atoms. Conjugated systems are more
Keynotes in Organic Chemistry
Keynotes in Organic Chemistry Second Edition ANDREW F. PARSONS Department of Chemistry, University of York, UK Wiley Contents Preface xi 1 Structure and bonding 1 1.1 Ionic versus covalent bonds 1 1.2
Story Behind the Well-Developed Chiral Lewis Acid in Asymmetric Diels-Alder reaction
Story Behind the Well-Developed Chiral Lewis Acid in Asymmetric Diels-Alder reaction Reporter: Zhang Sulei Supervisors: Prof. Yang Zhen Prof. Chen Jiahua Prof. Tang Yefeng 2015-10-05 1 Contents Background
CHEM ORGANIC CHEMISTRY
BRAZOSPORT COLLEGE LAKE JACKSON, TEXAS SYLLABUS CHEM 2423 - ORGANIC CHEMISTRY CATALOG DESCRIPTION: CHEM 2423 Organic Chemistry I. CIP 4005045203 A study of the nomenclature, classification and reactions
Some questions and answers that we will get out of this example synthesis:
UTLINE CE535 SESSIN 3 (2007) Page 24 The Synthesis of Cubane I am showing you this synthesis because it is elegant and exemplifies many different concepts. We can use it to talk in context about the philosophical
Lecture 4: Band theory
Lecture 4: Band theory Very short introduction to modern computational solid state chemistry Band theory of solids Molecules vs. solids Band structures Analysis of chemical bonding in Reciprocal space
Chem 232. Representation of Reaction Mechanisms. A Simple Guide to "Arrow Pushing"
Chem 232 D. J. Wardrop wardropd@uic.edu Representation of Reaction Mechanisms A Simple Guide to "Arrow Pushing" 1. For a given reaction, draw out the structure of the reactants and reagents. Check that
CHE1502. Tutorial letter 201/1/2016. General Chemistry 1B. Semester 1. Department of Chemistry CHE1502/201/1/2016
CE1502/201/1/2016 Tutorial letter 201/1/2016 General Chemistry 1B CE1502 Semester 1 Department of Chemistry This tutorial letter contains the answers to the questions in assignment 1. FIRST SEMESTER: KEY
Few Selected Total Synthesis in Group Meeting June 1, Anil Kumar Gupta
Few Selected Total Synthesis in 2007 Group Meeting June 1, 2007 Anil Kumar Gupta Total Synthesis without Protecting Groups Chemoselectivity!! Solution: Protecting group BUT..It adds. Cost Complexity of
Asymmetric Catalysis by Chiral Hydrogen-Bond Donors
Asymmetric Catalysis by Chiral Hydrogen-Bond Donors Angew. Chem. Int. Ed., 2006, 45, 1520~1543 Mark S. Taylor and Eric N. Jacobsen* Current Literature Presentation Zhenglai Fang Wipf s Group at Pitt Zhenglai
REARRANGEMENTS NOTES Mechanistic Aspects of Rearrangements
- 1 - REARRANGEMENTS NOTES Mechanistic Aspects of Rearrangements Nature of the Rearrangement It can vary from being truly stepwise to migration occurring in concert with initial ionisation. These two situations