Synthesis of γ-Amino Esters via Mn-Mediated Radical Addition to Chiral γ-Hydrazonoesters
摘要:
Highly stereoselective Mn-mediated couplings of alkyl iodides with chiral N-acylhydrazones bearing ester functionality afford a series of gamma-hydrazino esters, including gamma-substituted, alpha,gamma-disubstituted, and alpha,alpha,gamma-trisubstituted examples. In contrast to prior work with chiral N-acylhydrazones, high stereoselectivity was observed even in the absence of Lewis acid. Microwave-assisted acylation with trifluoroacetic anhydride and reductive N-N bond cleavage provided the gamma-amino ester functionality in a synthetically useful N-TFA-protected form.
Asymmetric hydroformylation catalyzed by homogeneous and polymer-supported platinum complexes containing chiral phosphine ligands
作者:Giovanni Parrinello、J. K. Stille
DOI:10.1021/ja00257a036
日期:1987.11
Hydroformylation de styrene, isobutyl-4styrene, vinyl-2 et methoxy-6 vinyl-2-naphtalenes, acetate de vinyle, methacrylate de methyle, norbornene, en presence de chlorure stanneux et en presence d'orthoformiate de triethyle
Hydride reduction of alpha, beta-unsaturated carbonyl compounds using chiral organic catalysts
申请人:MacMillan David
公开号:US20060161024A1
公开(公告)日:2006-07-20
Nonmetallic, chiral organic catalysts are used to catalyze the 1,4-hydride reduction of an α,β-unsaturated carbonyl compound. The α,β-unsaturated carbonyl compound may be an aldehyde or cyclic ketone, and the hydride donor may be a dihydropyridine. The reaction is enantioselective, and proceeds with a variety of hydride donors, catalysts, and substrates. The invention also provides compositions effective in carrying out the 1,4-hydride addition of α,β-unsaturated carbonyl compounds.
作者:Stéphane G. Ouellet、Jamison B. Tuttle、David W. C. MacMillan
DOI:10.1021/ja043834g
日期:2005.1.1
The first enantioselectiveorganocatalytic hydride reduction has been accomplished. The use of iminium catalysis has provided a new organocatalytic strategy for the enantioselectivereduction of beta,beta-substituted alpha,beta-unsaturated aldehydes to generate beta-stereogenic aldehydes. The use of imidazolidinone 2 as the asymmetric catalyst has been found to mediate the transfer of hydrogen to a
第一次对映选择性有机催化氢化物还原已经完成。亚胺催化剂的使用为β,β-取代的α,β-不饱和醛的对映选择性还原生成β-立体醛提供了一种新的有机催化策略。已发现使用咪唑烷酮 2 作为不对称催化剂可介导氢从 Hantzsch 乙酯到一大类烯醛底物的转移。催化剂 2 在选择性 E-烯烃还原之前加速 EZ 异构化的能力允许在这个操作简单的协议中实施几何不纯的烯醛。
Rh-Catalyzed Asymmetric Hydroformylation of Functionalized 1,1-Disubstituted Olefins
作者:Xiao Wang、Stephen L. Buchwald
DOI:10.1021/ja2092689
日期:2011.11.30
The first method for the highly enantioselective rhodium-catalyzedhydroformylation of 1,1-disubstituted olefins has been developed. By employing either of the P-chirogenic phosphine ligands BenzP* and QuinoxP*, linear aldehydes with β-chirality can be prepared in a highly enantioselective fashion with good chemo- and regioselectivities.