Chapter 5 Three and Four-Membered Ring Systems
|
|
|
- Leslie Robbins
- 5 years ago
- Views:
Transcription
1 Chapter 5 Three and Four-mbered ing ystems 5.1 Aziridines Aziridines are good alkylating agents because of their tendency to undergo ring-opening reaction with nucleophiles 例 mitomycin C antibiotic and antitumor activity aziridine ring C mitomycin C ing ynthesis 4 5 X 4 5 X thod otes 3 2 P + 3 Br - I I aminoalcohol or 3 aminoalcohol + 2 aminoalcohol + 3 PBr 2 chloroamine + a in DM olefin, IC, olefin, I 3, then LiAl 4 or P 3 Wenker synthesis Gabriel synthesis Azidines from azides and olefins Three-m Chinpiao Chen 2009/3/20 11:47 23
2 + s=l [-(arylsulfonyl)imino]- phenyliodinane 5-1 s ~50% ee h h P 5-1 J. ys. rg. Chem. 1998, 597; Can. J. Chem. 1998, 738. l=ts 2 Ts * 44% ee Chem. Commun. 1998, a l 2 (10 mol%) Ts Ts Cu-catalyst, M-5A * a Tetrahedron, 1998, 13485; Tetrahedron Lett. 1998, CC 2 Et [(η 5 -C 5 5 )Fe(C) 2 (TF)] + [BF 4 ] - C 2 Et J. rg. Chem. 1998, C + 2 C CC 2 Et Yb(Tf) 3 Chem. Lett. 1998, 685. C 2 C 2 Et 05-Three-m Chinpiao Chen 2009/3/20 11:47 24
3 + 2 CC 2 Et n 4 C 2 Et J. Chem. oc. Perkin Trans. 2, 1998, Ts TM Br- Cs 2 C TM J. rg. Chem. 1998, Ts Functionalization at nitrogen -ubstituent C 2 C 2 C()C 3 (C 2 ) 3 C 2 C 2 C C=CC C 2 eagent C 2 C 2, Et 3 3 CC (C 2 ) 3, C 2 + Et 3 - C 2 =CC C=CC C 2 =C= 2 a ing-opening reactions + 2 M 4, 29.5 o C = = 58 7 J. Am. Chem. oc. 1974, C Ar C 2 Ar 100 o C 2 C C 2 X Y 2 C Ar X Y C 2 05-Three-m Chinpiao Chen 2009/3/20 11:47 25
4 The ring-opening of aziridines to azomethine ylides and subsequent cycloaddition. Ar = C 6 4-4, C; X=Y = 2 CC=CC 2, Et 2 C=C 2 Et, C=, norbornene. Tetrahedron Lett. 1971, 473. Tol t- BuLi Li C 2 Et Et C Tetrahedron Lett. 1998, K [Bn 2 ] 2 Cu(C)Li 2 Ts Ts aza-payne rearrangement. Chem. oc. ev. 1998, 145. Ts Bn 2 4 c (Tf) 3 + Bn 5 ynlett, 1998, Bn 5 Boc TBDM Boc MgBr 2 TBDM Br Tetrahedron Lett. 1998, Cu(Tf) 2 J. rg. Chem. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 26
5 e e Bu 3 n ynlett, 1998, Fragmentation reactions o C o C xiranes (Epoxides) C 2 2 C(C 2 ) 4 C ing ynthesis chanism of epoxidation by peroxy acids. 05-Three-m Chinpiao Chen 2009/3/20 11:47 27
6 t-bu C Ti(i-Pr) 4, (-)-diethyl tartrate C1021 Asymmetric epoxidation of an allylic alcohols. Pure & Appl. Chem. 1983, rganic eactions, 1996, 48, 1. C 3 C 3 B, aq. dioxane Kt-Bu Br electivity of epoxide formation. J. Chem. oc. Perkin Trans. 2, 1993, Darzens reaction. Comprehensive rganic ynthesis, Vol. 2, 1991, p C 3 e Tetrahedron Lett. 1998, Mn Tetrahedron Lett. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 28
7 - = C = J. rg. Chem. 1998, Chem. Commun. 1998, 429. Mn X X t-bu t-bu J. Am. Chem. oc. 1998, l Z Mn 10 Tetrahedron Lett. 1998, (,)-13 t-bu Co Ac t-bu t-bu t-bu 13 J. rg. Chem. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 29
8 xone J. rg. Chem. 1998, J. rg. Chem. 1998, xone Et 2 C X 19 Chem. Commun. 1998, t-bu V t-bu t-bu 25 Tetrahedron Lett. 1998, Bn TE MCPBA Bn TE Tetrahedron Lett. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 30
9 Br- 35 l Chem. Commun. 1998, Cu(acac) 2 C C 2 DCM J. Am. Chem. oc. 1998, C 2 Br C a J. rg. chem. 1998, eactions - B E2 elimination and ring opening of oxiranes Bn LA J. eterocyclic Chem. 1998, 865. Bn Boc Et 2 Al 3 Boc 3 Tetrahedron Lett. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 31
10 TM 2 ynlett, 1998, 510. TM Lewis acid Tetrahedron Lett. 1998, 393. i 4 55 P 55 J. rg. Chem. 1998, TM TM TM Tetrahedron Lett. 1998, Li (-)-sparteine 63 t-bu 65 t-bu ymlett, 1998, Tetrahedron Lett. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 32
11 Li + J. Chem. oc. Perkin 1, 1998, Bn Bn TE Tf TBDP n-buli 2 Tol Bn J. rg. Chem. 1998, Bn TBDP 2 Tol LDA J. Am. Chem. oc. 1998, ' 2 n-buli Li ' Li Li : Li ' ' J. rg. Chem. 1998, ynlett, 1998, 337. Ar Pd(Ac) 2, PBu 3 C, t-bu Ar C Pd(Ac) 2, PBu 3 3A M, t-bu Tetrahedron, 1998, Tetrahedron Lett. 1998, Three-m Chinpiao Chen 2009/3/20 11:47 33
12 u(lll), cat. acetone yn. Commun. 1998, C, C 3 C Ti(TFA) 2 yn. Commun. 1998, X cat. Eu(dpm) 3 X Tetrahedron Lett. 1998, ml 2 = aryl X 2.2 ml 2 = aryl, alkyl ynlett, 1998, ml 2 Tetrahedron, 1998, Thiiranes thiirane thiirane-1-oxide thiirane-1,1-dioxide - - C - C C - ynthesis of thiiranes from oxiranes 05-Three-m Chinpiao Chen 2009/3/20 11:47 34
13 Y - - Y Polymerization initiated by nucleophilic attack. etc. t-bu t-bu C 2 2, 100 o C t-bu t-bu Tetrahedron Lett. 2001, C 3 50% a(aq) Bn(Et) 3 elv. Chim. Acta. 1999, benzene elv. Chim. Acta. 1920, irradiation Azirines C 2 C C 2 05-Three-m Chinpiao Chen 2009/3/20 11:47 35
14 3 + 3 heat/hv A base B heat C P 3 A: = =, =, 110 o C, 63%. = =, = et 2, 20 o C, 94%, =,, = (C 2 ) 6, hν, pentane, 93%. B: =, =, =, a, 2, 20 o C, 63%. C: = =, = Bu t, 120 o C, 57%. Tetrhedron Lett. 1995, J. Am. Chem. oc. 1995, Examples of addition reactions to C= bond of azirines Azirine eagent Product ef. EtMgBr 2 C 2 Et Py a b c 2 C d a. Tetrahedron lett. 1969, b. J. Am. Chem. oc. 1967, c. J. Am. Chem. oc. 1972, d. elv. Chim. Acta. 1979, Three-m Chinpiao Chen 2009/3/20 11:47 36
15 X X hν X heat X X X =, 70% X =, 90% X =, 200 o C, 80%. X =, 140 o C, 87%. Thermal and photochemical isomerization of 3-phenylazirines bearing conjugative substituents. Internal addition of nitrile ylides derived from azirines. 5.5 Diaziridines and 3-diazirines 4 diaziridine 3-diazirine Ag 2 hν heat 05-Three-m Chinpiao Chen 2009/3/20 11:47 37
16 Et p-ts liq. 3 F 3 C F 3 C Et Tetrahedron Lett. 2000, ynthesis of diaziridines 2 - ynthesis of 3-chlorodiaziridines from amidines Li, 2, a 2 2, DM, pentane J. Am. Chem. oc, 1992,959. irradiation Tetrahedron lett. 1998, xaziridines ArC 3 C 2 Tetrahedron Lett. 1998, C 2 05-Three-m Chinpiao Chen 2009/3/20 11:47 38
17 2 3 Bull. Acad. ci. U Div. Chem. ci. 1989, 793. Et 2 a 2 C 3 Chem.. Ber. 1958, Et 2 m-cpba, K 2 C 3, 2 2 J. Am. Chem. oc. 1989, As reagent for asymmetric oxygen transfer, Pure Appl. Chem. 1993, C Boc Boc Tetrahedron Lett. 1998, KMD 2 Tetrahedron, 1998, Et 2 C Et 2 C Et 2 C M M Et 2 C Tetrahedron Lett. 1988, Three-m Chinpiao Chen 2009/3/20 11:47 39
18 5.7 Azetidines and azetidinones Ts C 2 Et Br C 2 Et Ts P 3 J. rg. Chem. 1981, C C 2 = C 2 = 2 C 2 C 2 Ac C 2 2 C 2 2 C C a + C C 2 - C 2 05-Three-m Chinpiao Chen 2009/3/20 11:47 40
19 2 C LDA, 2 C TF, -78 o C C 2 Cbz Flavobacterium buteocens enzyme 2 C C 2 Cbz Cbz +, 2 C optically active Cbz 1. 2, Pd/C 1. ab 4 2. TM, TEA, Et 2 2. Ac 2, Py 2 C Cbz Cr 3, Py - ) 2 Mg C 2 PB = TM 2 1. Ts 3, TEA, C 3 C 2. 1, P() 2, DMAP 2 h 2 (Ac) 4 C 2 PB benzene C 2 PB 1. ai P(P) 2 2. (E)- Ag- C=C- Ac C 2 PB C 2 PB Ac 1. MCPBA 2. TLC sepn. C 2 PB Ac 2, Pd/C Ac C 2 (-)-Carpetimycin A 5.8 ther four-membered heterocycles xetanes 05-Three-m Chinpiao Chen 2009/3/20 11:47 41
20 obafluorin 2 conc (major) + (minor) 2 C CC 2 C 2 2 C C 2 2 C Thietanes Br ( 2 ) 2 C a + 2 Et Br - Br 05-Three-m Chinpiao Chen 2009/3/20 11:47 42
21 benzothietane naphtho[1,8-bc]thiete 700 o C C Torr J. Chem. oc. 1952, Tetrahedron Lett. 1980, C 2, Pb(Ac) 4 C 2 2, rt... J. Chem. oc. Perkin Trans.1, 1981, ome unsaturated four-membered rings C 2 C 2 oxete thiete 2,3-dihydroazete dimethyl 1,2-dihydrodiazete- 1,2-dicarboxylate 05-Three-m Chinpiao Chen 2009/3/20 11:47 43
Electrophilic Carbenes
Electrophilic Carbenes The reaction of so-called stabilized diazo compounds with late transition metals produces a metal carbene intermediate that is electrophilic. The most common catalysts are Cu(I)
James D. White. A very productive professor 64 students graduated from his lab 94 postdocs have worked in his lab. Education Experience
A very productive professor 64 students graduated from his lab 94 postdocs have worked in his lab Education Experience Fraser Fleming University of Drexel Pavel agory University of Michigan Cambridge University,
VINBLASTINE. H MeO 2 C MeO. OAc. CO 2 Me. Me H
VIBLATIE 2 C 1 C 2 Ac a 3: catharanthine C 2 Ac C 2 2: ( )-vindoline xidation 5' 2 C 3' 16' 20' Ac C 2 1: (+)-vinblastine b 4 C 2 TFAA, -50 C Polonovski fragmentation 6' 5' 16' C 2 5 TFA 4' 3' 15' 16'
CEM 852 Final Exam. May 6, 2010
CEM 852 Final Exam May 6, 2010 This exam consists of 7 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 150. n answering your questions,
Organocopper Reagents
rganocopper eagents General Information!!! why organocopper reagents? - Efficient method of C-C bond formation - Cu less electropositive than Li or Mg, so -Cu bond less polarized - consequences: 1. how
Chapter 4 Electrophilic Addition to Carbon Carbon Multiple Bonds 1. Addition of H X 2. Addition of H OH and addition of Y X 3. Addition to allene and
Chapter 4 Electrophilic Addition to Carbon Carbon Multiple Bonds 1. Addition of X 2. Addition of and addition of Y X 3. Addition to allene and alkyne 4. Substitution at α-carbon 5. eactions via organoborane
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
[3,3]-sigmatropic Processes. [2,3]-sigmatropic Processes. Ene Reactions. Generalized Sigmatropic Processes X,Y=C, N, O, S X,Y=C, N, O, S
![[3,3]-sigmatropic Processes. [2,3]-sigmatropic Processes. Ene Reactions. Generalized Sigmatropic Processes X,Y=C, N, O, S X,Y=C, N, O, S](/thumbs/94/119475672.jpg "[3,3]-sigmatropic Processes. [2,3]-sigmatropic Processes. Ene Reactions. Generalized Sigmatropic Processes X,Y=C, N, O, S X,Y=C, N, O, S")
Generalized igmatropic Processes [3,3]-sigmatropic Processes 1 3,=C,,, 1 3 3,=C,,, 3 [2,3]-sigmatropic Processes 1 3,=C,,, 1 3 Ene eactions 1 3 1 3 Cope earrangement [3,3]- igmatropic earrangements Transition
Comparative Synthesis of Ingenol. Tyler W. Wilson SED Group Meeting
Comparative Synthesis of Ingenol Tyler W. Wilson SED Group eting 2.27.07 Ingenol: Biology, Isolation, and istory During WWII a latex was manufactured by precipitating the milky juice of the Euphorbia Ingen
A Concise Synthesis of ( )- Aplyviolene Facilitated by a Stragetegic Ter<ary Radical Conjugate Addi<on
A Concise Synthesis of ( )- Aplyviolene Facilitated by a Stragetegic Ter
OC 2 (FS 2013) Lecture 3 Prof. Bode. Redox Neutral Reactions and Rearrangements
C 2 (F 203) Lecture 3 Prof. Bode edox eutral eactions and earrangements Types of edox eutral rganic eactions. eactions with no external reducing or oxidizing agent In this case, one part of the starting
Hennoxazole A. Philip Williams Group Meeting December 12, OMe. OMe 1 6 O H
ennoxazole A 1 6 11 17 24 Philip Williams Group eting December 12, 2007 Discovered Discovered by Paul cheuer at the University of awaii in 1991. Isolated 480mg ennoxazole A from 4.5kg from the sponge Polyfibrospongia
Zr-Catalyzed Carbometallation
-Catalyzed Carbometallation C C C C ML n C C ML n ML n C C C C ML n ML n C C ML n Wipf Group esearch Topic Seminar Juan Arredondo November 13, 2004 Juan Arredondo @ Wipf Group 1 11/14/2004 Carbometallation
TMSCl imidazole DMF. Ph Ph OTMS. Michael reaction. Michael reaction Ph R 3. epoxidation O R
eaction using diarylprolinol silyl ether derivatives as catalyst 1) C Et K C 3, ) MgBr, TF TMS hexane, 0 o C TBS p- C 6 4, T C Et 85%, 99% ee Angew. Chem., nt. Ed., 44, 41 (005). rg. Synth., 017, 94, 5.
JACS 1982: A Survey of Papers with a Focus on Synthetic Organic Chemistry
JAC 1982: A urvey of Papers with a Focus on ynthetic rganic Chemistry Baran Lab Group eting 15 ctober 2003 Carlos A. Guerrero eagents and thods 1 2 [] 2 2 1 1 PhC, Et 3 2 [] 2 1 2 1 By 1982, the [3 + 2]
Stereoselective reactions of the carbonyl group
1 Stereoselective reactions of the carbonyl group We have seen many examples of substrate control in nucleophilic addition to the carbonyl group (Felkin-Ahn & chelation control) If molecule does not contain
Highlights of Schmidt Reaction in the Last Ten Years
ighlights of Schmidt eaction in the Last Ten Years Dendrobates histrionicus Jack Liu ov. 18, 2003 Introduction Classical Schmidt reaction of aldehydes and carboxylic acids Classical Schmidt reaction of
Carbonyl Ylide Cycloadditions
Carbonyl Ylide Cycloadditions cond. icholas Anderson Denmark Group eting 07/13/10 Carbonyl Ylides Uncharged 1,3-Dipole Conjugated π-system ighly reactive on-isolable Generate in-situ Carbonyl Ylide Stability
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
Problem session (3) Daiki Kuwana. Please fill in the blank and explain reaction mechanisms and stereoselectivities.
Problem session (3) Daiki Kuwana Please fill in the blank and explain reaction mechanisms and stereoselectivities. 1. 1-1 1. (Ac) 2 (10 mol%), DPEphos (20 mol%) Et 3, toluene, 90 C 2. s 4 (14 mol%), M;
Asymmetric Lewis Base Strategies for Heterocycle Synthesis
Asymmetric Lewis Base trategies for eterocycle ynthesis Dr Andrew mith EatCEM, chool of Chemistry, University of t Andrews 1st cottish-japanese ymposium of rganic Chemistry, University of Glasgow Friday
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols B() 2 H H B() 2 H H Hu, X.-D.; Fan, C.-A.; Zhang, F.-M.; Tu, Y.
Strained Molecules in Organic Synthesis
Strained Molecules in rganic Synthesis 0. Introduction ~ featuring on three-membered rings ~ Tatsuya itabaru (M) Lit. Seminar 08068 for cyclobutadienes : see Mr. Yamatsugu's Lit. Sem. 069 eat of Formation
Answers To Chapter 7 Problems.
Answers To Chapter Problems.. Most of the Chapter problems appear as end-of-chapter problems in later chapters.. The first reaction is an ene reaction. When light shines on in the presence of light and
Total Syntheses of Minfiensine
Total Syntheses of Minfiensine Douany, A. B.; umphreys, P. G.; verman, L. E.*; Wrobelski, A. D., J. Am. Chem. Soc. 2008, ASAP. D: 10.1021/ja800163v Shen, L.; Zhang, M.; Wu, Y.; Qin, Y.*, Angew. Chem. nt.
CEM 852 Exam LDA, THF, 0 C, 15 min; then
CEM 85 Exam- April, 005 This exam consists of 5 pages. Please write ALL your answers in the answer books. Please write legibly and draw all structures clearly. Good luck. 1. Provide examples of the following
CHEM 234: Organic Chemistry II Reaction Sheets
EM234:rganichemistry eactionsheets ucleophilic addition at carbonyl groups: Grignards and reducing agents u: u u u: u u = or = or l u u u ucleophilic addition at carbonyl groups: oxygen and nitrogen nucleophiles:
Shi Asymmetric Epoxidation
Shi Asymmetric Epoxidation Chiral dioxirane strategy: R 3 + 1 xone, ph 10.5, K 2 C 3, H 2, C R 3 formed in situ catalyst (10-20 mol%) is prepared from D-fructose, and its enantiomer from L-sorbose oxone,
A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition
A ew Strategy for Efficient Synthesis of Medium and Large ing Lactones without High Dilution or Slow Addition BF 3 Et 2 TIPS 2,4,6-collidine n + n+2 ' ' Zhao, W.; Li, Z; Sun, J. J. Am. Chem. Soc. 2013
Suggested solutions for Chapter 41
s for Chapter 41 41 PBLEM 1 Explain how this synthesis of amino acids, starting with natural proline, works. Explain the stereoselectivity of each step after the first. C 2 C 2 3 CF 3 C 2 2 Pd 2 C 2 +
Molecular Rearrangements
Ø Migration of one the molecule group from one atom to another within Ø Generally the migrating group never leaves the molecule Ø There are five types of skeletal rearrangements- 1. Electron deficient
Total synthesis of Spongistatin
Literature Semminar 1. Introduction: Total synthesis of Spongistatin Chen Zhihua (M2) Isolation: Pettit et al. J. rg. Chem. 1993, 58, 1302. Kitagawa et al. Tetrahedron Lett. 1993, 34, 1993. Fusetani et
CHEM 203. Final Exam December 15, 2010 ANSWERS. This a closed-notes, closed-book exam. You may use your set of molecular models
CEM 203 Final Exam December 15, 2010 Your name: ANSWERS This a closed-notes, closed-book exam You may use your set of molecular models This test contains 15 pages Time: 2h 30 min 1. / 16 2. / 15 3. / 24
Synthetic Developments Towards the Preparation of Erythromycin and Erythronolide Derivatives
ynthetic Developments Towards the Preparation of Erythromycin and Erythronolide Derivatives Russell C. mith Denmark Group Meeting 8-9-2005 most extensive project in organic synthesis this phenomenon is
CEM 852 Exam-2 April 11, 2015
CEM 852 Exam-2 April 11, 2015 This exam consists of 6 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 100. In answering your questions,
Julio Alvarez-Builla, Juan Jose Vaquero,
Edited by Julio Alvarez-Builla, Juan Jose Vaquero, and Jose Barluenga Modern Heterocyclic Chemistry Volume 1 WILEY- VCH WILEY-VCH Verlag GmbH & Co. KG aa List of Contributors XV Volume 1 1 Heterocyclic
Asymmetric Nucleophilic Catalysis
Asymmetric ucleophilic Catalysis Chiral catalyst X 2 Chiral catalyst X = alkyl, X 1 2 1 Vedejs, E.; Daugulis,. J. Am. Chem. Soc. 2003, 125, 4166-4173 Shaw, S. A.; Aleman,.; Vedejs, E. J. Am. Chem. Soc.
Spiro Monophosphite and Monophosphoramidite Ligand Kit
Spiro Monophosphite and Monophosphoramidite Ligand Kit metals inorganics organometallics catalysts ligands custom synthesis cgm facilities nanomaterials 15-5162 15-5150 15-5156 15-5163 15-5151 15-5157
Mechanism Problem. 1. NaH allyl bromide, THF N H
Mechanism Problem 1. a allyl bromide, TF 2. 9-BB (1.2 equiv), TF, rt; ame (1.2 equiv); t-buli (2.4 equiv), TMEDA (2.4 equiv) 30 to rt; allyl bromide; 30% 2 2, aq. a, 0 C (58% yield) Mechanism Problem 9-BB
Lecture 6: Transition-Metal Catalysed C-C Bond Formation
Lecture 6: Transition-Metal Catalysed C-C Bond Formation (a) Asymmetric allylic substitution 1 u - d u (b) Asymmetric eck reaction 2 3 Ar- d (0) Ar 2 3 (c) Asymmetric olefin metathesis alladium π-allyl
CHEM 330. Final Exam December 5, 2014 ANSWERS. This a closed-notes, closed-book exam. The use of molecular models is allowed
CEM 330 Final Exam December 5, 2014 Your name: ASWERS This a closed-notes, closed-book exam The use of molecular models is allowed This exam consists of 12 pages Time: 2h 30 min 1. / 30 2. / 30 3. / 30
transmetallate displace ox. add. M + (insert) (β-elim.)
Chapter IV. Transition Metal σ-alkyl Complexes I. General For much of the rest of this course it will be necessary to understand how σ-alkyl metal complexes are formed and how they react. This is summarized
Huang, C.; Gevorgyan, V. J. Am. Chem. Soc. 2009, 131, Daniel Tzvi Cohen Short Literature Feb. 23, MeO HO OH. COOH ( )-Plicatic Acid OH OH
Asymmetric Total Synthesis of ( )-Plicatic Acid via a Highly Enantioselective and Diastereoselective Nucleophilic Epoxidation of Acyclic Trisubstituted lefins H H H H CH ( )-Plicatic Acid H H Sun, B.F.;
Synthetic Methodology. Using Tertiary Phosphines. as Nucleophilic Catalysts
Synthetic Methodology Using Tertiary osphines as Nucleophilic Catalysts 1 3 2 u 2 (P 3 ) 3 4 1 2 D. Ma, X. Lu 1988 1 2 Pd 2 (dba) 3.CCl 3 /P 3 /Ac or Pd(Ac) 2 /P 3 1 2 B. M. Trost 1988 1 3 2 u 2 (P 3 )
Conjugate (1,4-) addition
1 Conjugate (1,4-) addition uc R 1 R 2 uc R 1 R 2 uc R 1 E R 2 E ucleophilic attack on C=C bond normally requires electron deficient alkene Know as 1,4-addition or conjugate addition As enolate formed
JOC Year-in-Review, 1984
Baran Lab Group eting JC Year-in-eview, 198 Y oshihiro Ishihara Statistics for J. rg. Chem. 198, Volume 9, Issues 1-26: 1313 Papers 1 erbert C. Brown 8 Albert Padwa 8 Leo A. Paquette 7 Dale L. Boger 7
Carbenes and Carbene Complexes I Introduction
Carbenes and Carbene Complexes I Introduction A very interesting (honest) class of radical-like molecules Steadily becoming more important as they find far more synthetic applications We will primarily
CHEM 203. Final Exam December 18, This a closed-notes, closed-book exam. You may use your set of molecular models
CEM 203 Final Exam December 18, 2013 Your name: This a closed-notes, closed-book exam You may use your set of molecular models This test consists of 10 pages Time: 2h 30 min 1. / 20 2. / 20 3. / 30 4.
Chiral Brønsted Acid Catalysis
Chiral Brønsted Acid Catalysis Aryl Aryl Aryl Aryl S CF 3 2 P Fe CF 3 CF 3 2 Jack Liu ov. 16, 2004 CF 3 Introduction Chiral Brønsted acid catalysis in nature: enzymes and peptides Chiral Brønsted acid
EWG EWG EWG EDG EDG EDG
Functional Group Interconversions Lecture 4 2.1 rganic Synthesis A. Armstrong 20032004 3.4 eduction of aromatic systems We can reduce aromatic systems to cyclohexanes under very forcing hydrogenolytic
R or S? oxidation #: hybridization:
Remember Lone pair-assisted ionization. ame 15 F07-Exam o. 1 Page I. (0 points) The following compounds are those used in our study on the enzymatic transformation of cholesterol to pregnenolone. 1) Designate
Organic Tutorials 3 rd Year Xmas Vac
rganic Tutorials 3 rd Year Xmas Vac Third Year Reactive Intermediates: Radicals, Arynes, Carbenes etc. Radicals References: Moody and Whitham Reactive Intermediates, xford Chemistry Primer 8; Carey and
Olefin-Forming Reactions I
C549 R.M. Williams lefin-forming Reactions I The McMurry lefination Reaction. An important alternative to the acyloin condensation is the McMurry olefination which is a free radical coupling reaction initiated
R or S? 2) oxidation numbers of the designated carbon atoms: note: An oxidation number must have a sign. F 3 C OCH 3 oxidation #: OH.
ame 5 F0-Exam o. Page I. ( points) The following compounds are those used in our study on the mechanism of the chemical carcinogenesis of benzo[a]pyrene. ) Designate in each of the boxes below the stereochemistry
Chapter 12. Alcohols from Carbonyl Compounds Oxidation-Reduction & Organometallic Compounds. Structure
Chapter 12 Alcohols from Carbonyl Compounds xidation-eduction & rganometallic Compounds Created by Professor William Tam & Dr. Phillis Chang Structure ~ 120 o ~ 120 o C ~ 120 o Carbonyl carbon: sp 2 hybridized
Three Type Of Carbene Complexes
Three Type f arbene omplexes arbene complexes have formal metal-to-carbon double bonds. Several types are known. The reactivity of the carbene and how it contributes to the overall electron counting is
Part C- section 1 p-bonds as nucleophiles
Part C- section 1 p-bonds as nucleophiles Chemistry of Alkenes (Ch 8, 9, 10) - the double bond prevents free rotation - isomerism cis and trans - nomenclature E and Z (3 or 4 different substituents around
VI. Metal alkyls from oxidative addition / insertion
V. Metal alkyls from oxidative addition / insertion A. Carbonylation - C insertion very facile, metal acyls easily cleaved, all substrates which undergo oxidative addition can in principle be carbonylated.
Abstracts VII. Phthalocyanines and Related Compounds. M. S. Rodr guez-morgade and T. Torres
VII p1 thalocyanines and Related Compounds 17.9.24 M.. Rodr guez-morgade and T. Torres This review updates the original cience of ynthesis chapter (ection 17.9) on phthalocyanines and various ring-fused,
Suggested solutions for Chapter 30
s for Chapter 30 30 PRBLEM 1 uggest a mechanism for this synthesis of a tricyclic aromatic heterocycle. 2 Cl base A simple exercise in the synthesis of a pyridine fused to a pyrrole (or an indole with
Structure and Reactivity: Prerequired Knowledge
Structure and eactivity: Prerequired Knowledge!!! The concepts presented in this summary are required for lecture and examination!!! 1. Important Principles in rganic Chemistry In general, structures which
Chiral Catalyst II. Palladium Catalysed Allylic Displacement ( -allyl complexes) 1. L n Pd(0) 2. Nuc
Chiral Catalyst II ast lecture we looked at asymmetric catalysis for oxidation and reduction Many other organic transformations, this has led to much investigation Today we will look at some others...
11-Step Enantioselective Synthesis of ( )-Lomaiviticin Aglycon
11-Step Enantioselective Synthesis of ( )-Lomaiviticin Aglycon Seth B. erzon, Liang Lu, Christina M. Woo, and Shivajirao L. Gholap J. Am. Chem. Soc. ASAP DI 10.1021/ja200034b Melissa Sprachman Current
Lecture 1 ADVANCED SYNTHESIS Stereochemistry Introduction
ecture 1 ADVACED YTEI tereochemistry Introduction ne of the most important issues in modern organic synthesis ost natural compounds are enantiomerically pure Frequently different enantiomers have different
3.7. Pyridinium Chloro Chromate (PCC):
xidation 3.7. Pyridinium hloro hromate (P): 97 l l r r 3 r l P is a very important oxidising reagent which will give controlled oxidation in the case of primary alcohol. It does not give over oxidation
A 1,3 Strain and the Anomeric Effect. Michael Shaghafi Chem. Topics Feb. 6, 2012
A 1,3 Strain and the Anomeric Effect Michael Shaghafi Chem. Topics Feb. 6, 2012 Introduction: Definition of A 1,3 Strain m L L m m 3 L 3 1 1 otation about σ-bond between α-stereocenter and olefin is associated
Chem 263 Notes March 2, 2006
Chem 263 Notes March 2, 2006 Average for the midterm is 102.5 / 150 (approx. 68%). Preparation of Aldehydes and Ketones There are several methods to prepare aldehydes and ketones. We will only deal with
[3,3]-Sigmatropic rearrangements
![[3,3]-Sigmatropic rearrangements](/thumbs/75/71504906.jpg "[3,3]-Sigmatropic rearrangements")
1 [3,3]-Sigmatropic rearrangements heat R 1 R 3 R 1 R 3 R 1 R 3 A class of pericyclic reactions whose stereochemical outcome is governed by the geometric requirements of the cyclic transition state Reactions
Keisuke Suzuki. Baran lab Group Meeting 6/11/16. Shigenobu Umemiya. Akira Suzuki. Takanori Suzuki (Hokkaido University)
197.D., Teruaki Mukaiyama, University of Tokyo 193 Assistant Professor, Keio University 197 Lecturer, Keio University 199 Assocate Professor, Keio University 1990 Visiting Professor, ET 1994 ull Professor,
Reporter: Yue Ji. Date: 2016/12/26
Literature Report (11) Total Synthesis of Rubriflordilactone B Reporter: Yue Ji Checker: Mu-Wang Chen Date: 2016/12/26 Yang, P.; Yao, M.; Li, J.; Li, Y.; Li, A.* Angew. Chem. Int. Ed. 2016, 55, 6964. Laboratory
Problem Session(5) Please provide each reaction mechanisms and explain the stereoselectivities.
Problem ession(5) Please provide each reaction mechanisms and explain the stereoselectivities. 2017.10.28. iroaki Matoba Boc 1.BF 3 Et 2,C 2 Cl 2,-78 C; allyltm,-78to-20 C 2.MsCl,Et 3,C 2 Cl 2,0 Ctort
Additions to Metal-Alkene and -Alkyne Complexes
Additions to tal-alkene and -Alkyne Complexes ecal that alkenes, alkynes and other π-systems can be excellent ligands for transition metals. As a consequence of this binding, the nature of the π-system
Although we won t go into this, the reactions can be regioselective if non-symmetrical alkenes are used.
2.1 rganic ynthesis A. Armstrong - 2004-2005 Functional Group Interconversions - Lecture 5 ection 5: xidation of C- bonds bearing no heteroatom 5.1 xidation of allylic positions Many reagents will do this
Catalytic Reactions in Organic Synthesis
17 April, 2008 Catalytic eactions in rganic Synthesis hodium Complexes and edox Catalysts Koichi AASAKA, Motoki YAMAE, Shunsuke CIBA Division of Chemistry and Biological Chemistry, School of ysical and
Chapter 5B. Functional Group Transformations: The Chemistry. Related Reactions
Chapter 5B Functional Group Transformations: The Chemistry of fcarbon-carbon C b π-bonds B d and Related Reactions Oxymercuation-Demercuration Markovnikov hydration of a double bond 1 Mechanism Comparision
Section Practice Exam II Solutions
Paul Bracher Chem 30 Section 7 Section Practice Exam II s Whether problems old r problems new, You d better practice, r you ll fail exam II. -- Anonymous TF Problem 1 a) Rank the following series of electrophiles
Convergent Route to ent-kaurane Diterpenoids: Total Synthesis of Lungshengenin D and 1α6α- Diacetoxy-ent-kaura-9(11),16-dien- 12,15-dione
Convergent Route to ent-kaurane Diterpenoids: Total Synthesis of Lungshengenin D and 1α6α- Diacetoxy-ent-kaura-9(11),16-dien- 12,15-dione Xiangbo Zhao, Wu Li, Junjie Wang, and Dawei Ma* Shanghai Institute
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.
H CH 2 -OH (4) H b. H H (5) (6) a. b.
ame 215 F010-Exam o. 2 Page 2 I. (15 points) For each of the following pairs of compounds, predict which compound is more acidic. Compare the two underlined s for each pair and circle the compound that
Synthetic Efforts Toward Palau'amine
ynthetic Efforts Toward Palau'amine Doug Behenna, Ryan McFadden Eric Ashley, Jenn tockdill Akihiko Iwashita August 9, 2004 2 2 2 Isolation of Palau'amine and Congeners R 2 R 1 R 1 R 2 2 2 2 2 2 2 R 1 =
Enantioselective Synthesis of Pactamycin, a Complex Antitumor Antibiotic
Journal Club (3) Tomoya akamura Enantioselective Synthesis of Pactamycin, a Complex Antitumor Antibiotic Justin T. Malinowski, Robert J. Sharpe, Jeffrey S. Johnson Science 03, 30, 80 8.. Introduction -.
(c) S. orbital is (a) 1 (b) 0 (c) +1 (d) undefined.
QUESTI PAPER CEMISTRY-CY Q. Q.25 : Carry E mark each.. The maximum non-pv work that a system can perform at constant P is 2. Consider the reaction : G S A A B C The unit of the thermodynamic equilibrium
Short Lit
Short Lit. - 7-12-2010 Jonathan A. Brekan a Department of Chemistry, orthwestern University, 2145 Sheridan Road, 60208, Evanston, Illinois, United States of America Citronellal Monoterpenoid distillate
JOC: 1985 Year in Review
Baran Group eting JC: 1985 Year in eview Syntheses discussed: thodoligies discussed: Quadrone 2 C (+)-irsutic Acid C (±) Coriolin (!)-Longifolene (!)-astanecine Manganese (III)-mediated "-lactone annulation
CHEM 203. Final Exam December 18, 2013 ANSWERS. This a closed-notes, closed-book exam. You may use your set of molecular models
CEM 203 Your name: Final Exam December 18, 2013 ANSWERS This a closed-notes, closed-book exam You may use your set of molecular models This test consists of 10 pages Time: 2h 30 min 1. / 20 2. / 20 3.
Epoxidation with Peroxy Acids
Epoxidation with Peroxy Acids RC 3 R C more reactive more likely Freccero, M.; Gandolfi, R.; Sarzi-Amadè, M.; Rastelli, A. J. rg. Chem. 2000, 65, 2030. Singleton, D. A.; Merrigan, S. R.; Liu, J.; ouk,
Mild Cobalt-Catalyzed Hydrocyanation of Olefins with Tosyl Cyanide
Mild Cobalt-Catalyzed ydrocyanation of lefins with Tosyl Cyanide 1 3 2 + Ts Co cat., Si 3 Et, 1-3 h, T 1 2 3 Gaspar, B.; Carreira, E. M. Angew. Chem. Int. Ed. ASAP Current Literature Kalyani Patil 12 May
Direct, Catalytic Hydroaminoalkylation of Unactivated Olefins with N-Alkyl Arylamines
Current Literature - May 12, 2007 Direct, Catalytic ydroaminoalkylation of Unactivated lefins with -Alkyl ylamines ' '' Ta[ 2 ] 5 (4-8 mol%), 160-165 o C 24-67h 66-95% ' '' S. B. erzon and J. F. artwig,
ANSWER GUIDE APRIL/MAY 2006 EXAMINATIONS CHEMISTRY 249H
AWER GUIDE APRIL/MAY 2006 EXAMIATI CEMITRY 249 1. (a) PDC / C 2 2 (b) t-bume 2 i (1 equiv) / imidazole (1 equiv) i TBDM protection of the less sterically hindered alcohol (c) BuLi (1 equiv) then (d) 2
water methanol dimethyl ether Ether can only act as a hydrogen bond acceptor H-bond acceptor O R
Chapter 14: Ethers and Epoxides; Thiols and Sulfides 14.1 Introduction to Ethers An ether group is an oxygen atom that is bonded to two carbons. The ether carbons can be part of alkyl, aryl, or vinyl groups.
Functional Group Transformations
Ways to make esters Baeyer-Villiger oxidation Favorskii rearrangement C 2 Et aet/et mcpba Mitsunobu reaction C 2 + ' DEAD, PPh 3 C 2 ' Ph 3 P Et 2 C C 2 Et Ph 3 P Et 2 C C 2 Et Ph 3 P Et 2 C C 2 Et + C
Suggested solutions for Chapter 32
s for Chapter 32 32 PBLEM 1 Explain how the stereo- and regio- chemistry of these reactions are controlled. Why is the epoxidation only moderately diastereoselective, and why does the amine attack where
Heterocyclic Chemistry
Heterocyclic Chemistry Third Edition Thomas L. Gilchrist University of Liverpool 1 Longman Contents Preface to the third edition Preface to the second edition Preface to the first edition Acknowledgements
LG XH. Alicyclic and Heterocyclic Chemistry. Lecture 8. Synthesis of four-membered rings (irreversible reactions only)
Alicyclic and eterocyclic hemistry. Lecture 8 ynthesis of four-membered rings (irreversible reactions only) Because of the strain in the rings, the syntheses of this size of ring must be irreversible just
CYCLOBUTADIENE IN ORGANIC SYNTHESIS
Lit. Seminar 061129 CYCLBUTADIENE IN GANIC SYNTESIS Usage of Unstable Intermediate: Cyclobutadiene as A Case 0. Introduction (C) 3 Fe 2 steps Kenzo YAMATSUGU (M2) (+)-Asteriscanolide difficulty to use
Copper-Catalyzed Reaction of Alkyl Halides with Cyclopentadienylmagnesium Reagent
Copper-Catalyzed eaction of Alkyl Halides with Cyclopentadienylmagnesium eagent Mg 1) cat. Cu(Tf) 2 i Pr 2, 25 o C, 3 h 2) H 2, Pt 2 Masahiro Sai, Hidenori Someya, Hideki Yorimitsu, and Koichiro shima
Application of Two Direct C(sp 3 )-H Functionalizations for the Total Synthesis of (+)-Lactacystin
Application of Two Direct C(sp 3 )- Functionalizations for the Total Synthesis of (+)-Lactacystin two stereoselective C(sp 3 )- functionalisations 2 C S Ac (S)-pyroglutaminol (+)-lactacystin S. Yoshioka,
2.222 Practice Problems 2003
2.222 Practice Problems 2003 Set #1 1. Provide the missing starting compound(s), reagent/solvent, or product to correctly complete each of the following. Most people in the class have not done this type
mcpba e.g. mcpba (major) Section 7: Oxidation of C=X bonds
Section 7: xidation of C=X bonds Functional Group Interconversions - Lecture 6 7.1 Epoxidation of Alkenes Epoxides are VEY useful in synthesis - the strain of the three membered ring makes these cyclic
CuI CuI eage lic R tal ome rgan gbr ommon
Common rganometallic eagents Li Et 2 Li Mg Et 2 Li alkyllithium rignard Mg Mg Li Zn TF ZnCl 2 TF dialkylzinc Zn 2 2 Zn Li CuI TF ganocuprate CuI 2 2 CuI common electrophile pairings ' Cl ' '' ' ' ' ' '