CHO. OMe. endo. xylene, 140 o C, 2 h 70% 1. CH 2 (OMe) 2, MeOH TsOH, rt 2. Bu 2 O, 1,2-dichloroethane 140 o C, 2 h 3. 6 M HCl, THF, rt 44%

Transcription

1 VII Abstracts 2010 p Arene rganometallic Complexes of Chromium, Molybdenum, and Tungsten M. Uemura This review is an update to Section 2.4 and covers the literature from 1999 to (h 6 -Arene)chromium complexes have been considerably developed in organic synthesis on the basis of the strong electron-withdrawing ability and steric effect of the tricarbonylchromium fragment. The corresponding arenechromium complexes of unsymmetrical 1,2- or 1,3-disubstituted arene ligands are nonsuperimposable on their mirror images. Catalytic asymmetric synthesis of the planar chiral arenechromium complexes with chiral catalysts has been actively developed. The planar chiral arenetricarbonylchromium complexes have been widely employed in asymmetric synthesis, natural product synthesis, and increasingly as chiral ligands in asymmetric catalysis. This review focuses on the synthesis of planar chiral arenechromium complexes, and their applications in organic synthesis. () 2 B (C) 3 Cr C Me Br 5 mol% Pd(P 3 ) 4 a 2 C 3, Me 2, 75 o C 74% (C) 3 Cr C Me (+) endo xylene, 140 o C, 2 h 70% 1. C 2 (Me) 2, Me Ts, rt 2. Bu 2, 1,2-dichloroethane 140 o C, 2 h 3. 6 M Cl, TF, rt 44% (C) 3 Cr (C) 3 Cr C Me exo C Me ent-exo Keywords: asymmetric hydroboration asymmetric reduction of ketones atropisomer catalytic asymmetric synthesis chromium migration cross coupling cycloisomerization enantioselective lithiation gold catalysts higher-order cycloaddition nucleophilic substitution molecular switch axially chiral biaryl palladium catalyst planar chirality radical coupling 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

2 VIII Science of Synthesis Abstracts 2010 p Diazo-1-silylalkanes Y. ari, T. Aoyama, and T. Shioiri This manuscript is an update to Section describing methods for the synthesis and applications of 1-diazo-1-silylalkanes. This update focuses on papers published in the period Me 3 Si MgBr 2 TF, 78 o C Me 3 Si 2 Keywords: silyldiazoalkanes diazo(trimethylsilyl)methane alkylidene carbenes Colvin rearrangement insertion reaction cyclopropanation [3+2] cycloaddition diazo(silyl)acetates diazo(silyl)methyl ketones 2010 p Aluminum ydrides. aka and S. Saito This manuscript is an update to the earlier Science of Synthesis contribution describing methods for the preparation of aluminum hydrides used for organic synthesis, and recent advances in synthetic applications of aluminum hydrides. Various chemoselective reductions, such as partial reduction of esters, nitriles, or amides to aldehydes, are possible using aluminum hydrides with suitable ligands. Me a + Al Me t-buk, toluene, t-bume <15 o C, 1 h 95% Bn Bn Keywords: aluminum compounds chemoselectivity hydroalumination metal hydrides reduction reductive cyclization regioselectivity stereoselective synthesis 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

3 Abstracts IX 2010 p Aluminum alides. aka and S. Saito This manuscript is an update to the earlier Science of Synthesis contribution describing methods for the preparation of aluminum halides used for organic synthesis, along with recent synthetic applications of aluminum halides. Me Et 2 AlCl, toluene 0 o C to rt 93% Me Al Cl Keywords: acid catalysts aluminum compounds bromides chiral compounds chlorides halides iodides ionic liquids Lewis acid catalysts salen complexes 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

4 X Science of Synthesis Abstracts 2010 p Triorganoaluminum Compounds M. ishi and. Takikawa This manuscript is an update to the earlier Science of Synthesis contribution describing applications of triorganoaluminums and related compounds. It focuses on selective carboalumination, catalytic enantioselective conjugate additions, and carbonyl additions covered in the literature over the period In addition, activations of C-F and C- bonds are of increasing importance in organoaluminum chemistry. Pr i 1. 5 mol% Cl Zr Cl Pr i Me 3 Al, MA diastereomer separation 79%; dr 40:1; 98% ee 90% ee siphonarienal C MA = methylaluminoxane Keywords: carboalumination carbonyl additions conjugate addition reactions coupling reactions regioselectivity enantioselectivity C- bond activation C-F bond activation 2010 p Gallium Compounds M. Yamaguchi This manuscript is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of organogallium compounds as well as their application in organic synthesis. It focuses on the literature published in the period Me Me Me Me GaCl 3 (0.25 equiv) Pr i 91% C Pr i C Me Me Keywords: catalysis complexation gallium compounds Lewis acid catalysts metal alkyl complexes organometallic reagents oxidative addition 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

5 Abstracts XI 2010 p Product Class 3: Indium Compounds S. Araki and T. irashita This manuscript is a revision update to the earlier Science of Synthesis contribution describing methods for the synthesis of indium compounds. More recent developments in this area, in particular chemical transformations using indium reagents, have been reviewed. X + In InL n Keywords: allylic compounds allenic compounds allylation Barbier reaction carbon-metal bonds carbon carbon coupling reactions indium compounds Lewis acid catalysts transmetalation 2010 p Barium Compounds A. Yanagisawa This manuscript is an update to the earlier Science of Synthesis contribution describing methods for the application of barium compounds in organic synthesis. It focuses on the literature published in the decade up to mol% Bn 2 C + 10 mol% Ba(iPr) 2 DME, 0 o C, 24 h 85% (2 equiv) Bn 2 C R + Bn 2 C 99% ee >20:1 Keywords: aldol reaction b-amino carbonyl compounds asymmetric catalysis barium compounds conjugate addition cross-coupling reactions Diels Alder reaction 1,5-di Updated Section 2010 Completely Revised Contributions ew ew Contributions

6 XII Science of Synthesis Abstracts ketones homocoupling b-hydroxy carbonyl compounds Mannich-type reaction propargylic compounds ew p The Catalytic Use of Lithium Compounds for Bond Formation S. Matsunaga The catalytic use of lithium compounds as Lewis bases and Brønsted bases is introduced. Several C-C bond-forming (enantioselective) transformations, such as aldol reactions, Mannich reactions, cyanation, conjugate additions, sulfur ylide additions for oxirane and oxetane synthesis, and others, are described. + TMSC 10 mol% (R)-BIL 10 mol% LiiPr toluene, 78 o C, 1 h 96%; 98% ee TMS C Keywords: asymmetric aldol reaction asymmetric Mannich reaction asymmetric cyanation lithium compounds Lewis base catalysts asymmetric conjugate addition reactions asymmetric Michael reaction sulfur ylides oxetane oxiranes Brønsted base catalysts ew p The Catalytic Use of Sodium Compounds for Bond Formation T. Arai Safe and inexpensive sodium reagents are promoted as versatile Lewis base, Lewis acid, and combination acid base catalysts in green chemistry. Sodium-containing heterobimetallic asymmetric complexes enable highly stereoselective catalysis of transformations such as Michael reactions, cyclopropanation, and the enry reaction. TMS TMS C Me Cl 3 C TMS sodium catalysis: safe and inexpensive Bn 2 EtS S C 2 Bn C 2 Bn Keywords: sodium compounds catalysis asymmetric synthesis Mukaiyama reaction Michael reaction 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

7 Abstracts XIII 2010 p Pyridazines J. Zhang This manuscript is an update of the original Science of Synthesis chapter and includes methods for the preparation of pyridazines and pyridazinones described in the literature up to Methods proceeding by condensation of diketones, keto acids, or keto esters with hydrazine, and Diels Alder reaction of 1,2,4,5-tetrazines and ketones are covered, as well as the application of halopyridazines in palladium-catalyzed cross-coupling reactions. + toluene, silica gel 110 o C, 10 h 98% Keywords: pyridazines ring closure condensation reactions dicarbonyl compounds Diels Alder reaction cross-coupling reactions 2010 p Synthesis with Retention of the Functional Group (Update 1) G. Landelle and J.-F. Paquin This manuscript is an update to the earlier Science of Synthesis contribution, and specifically describes methods involving conjugate addition to a,b-unsaturated carboxylic acids. It focuses on the literature published in the period C 2 BuLi, CuI, BF 3 Et 2 Et 2, 75 o C to rt 86% Bu C 2 Keywords: conjugate addition carboxylic acids unsaturated compounds organometallic reagents stereoselectivity regioselectivity 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

8 XIV Science of Synthesis Abstracts 2010 p Synthesis with Retention of the Functional Group (Update 2) J. L. Gleason and E. A. Tiong This manuscript is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of carboxylic acids. It focuses on direct a-alkylations of carboxylic acids and diastereoselective a-alkylation of carboxylic acid derivatives used in carboxylic acid synthesis. Me BnBr, LDA, LiCl TF, 0 o C, 15 min 90%; 94% de Me Bn 2 S 4 dioxane, reflux 95% Bn Keywords: alkylation carboxylic acid chiral auxiliary enolates alkyl halides tertiary stereocenters quaternary stereocenters ew p Product Class 15: Polyamides T. igashihara and M. Ueda This manuscript describes methods for the synthesis of polyamides, especially focusing on recent advances in aromatic polyamides as well as synthesis of block copolymers, hyperbranched polymers, and dendrimers. n aliphatic Ar 1 Ar 2 m Ar 1 n n n n aliphatic aromatic aromatic Keywords: amides condensation reactions dendrimers diamines dicarboxylic acids polymerization polymers 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

9 Abstracts XV 2010 p itrones and Cyclic Analogues P. Merino This chapter is an update to the previous Science of Synthesis contribution describing methods for the synthesis of nitrones and cyclic analogues. It covers the literature published in the period R 3 R3 [] [] R3 [] R3 2 R 3 R 4 R 5 1,3-dipolar cycloaddition ux nucleophilic addition R 5 u R 2 R 4 R 3 R 3 X Keywords: nitrones hydroxylamines amines imines oxidation isoxazolidines carbon nitrogen bonds dipolar cycloaddition nucleophilic addition nitrogen heterocycles 2010 p Reductive Amination of Carbonyl Compounds P. Margaretha This chapter summarizes syntheses of both achiral and chiral amines, either via direct reductive amination of carbonyl compounds or by two-step reactions, wherein the first step consists of conversion of the carbonyl compound into an -derivative (-alkylidenealkylamine, enamine, imine, oxime, or oxime ether), which, in the second step, is then 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions

10 XVI Science of Synthesis Abstracts reduced to the desired amine product. It is shown that primary, secondary, and tertiary amines are easily accessible synthetic targets. either -protected amines (e.g., amides) nor amines containing a functional group of higher priority (e.g., amino acids) are taken into account in this survey. 1. R 3 R 4 2. reduction R 3 R 4 R 3 2 R 3 reduction R 3 R 3 R 4 = CR 5 R 6 R 5 R 6 R 3 R 4 reduction R 3 R reduction 2 Keywords: amination amines -alkylidenealkylamines enamines imines oximes oxime ethers carbonyl compounds reduction enantioselective reactions 2010 Updated Section 2010 Completely Revised Contributions ew ew Contributions