[EN] ASYMMETRIC MICHAEL AND ALDOL ADDITION USING BIFUNCTIONAL CINCHONA-ALKALOID-BASED CATALYSTS<br/>[FR] ADDITIONS ASYMETRIQUES DE MICHAEL ET D'ALDOL UTILISANT DES CATALYSEURS BIFONCTIONNELS A BASE DE CINCHONINE
申请人:UNIV BRANDEIS
公开号:WO2005121137A1
公开(公告)日:2005-12-22
One aspect of the present invention relates to quinine-based and quinidine-based catalysts. Another aspect of the invention relates to a method of preparing a derivatized quinine-based or quinidine-based catalyst comprising 1) reacting quinine or quinidine with 5 base and a compound that has a suitable leaving group, and 2) converting the ring methoxy group to a hydroxy group. Another aspect of the present invention relates to a method of preparing a chiral, non-racemic compound from a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral ketone, comprising the step of: reacting a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral 10 ketone with a nucleophile in the presence of a catalyst; thereby producing a chiral, non racemic compound; wherein said catalyst is a derivatized quinine or quinidine. Another aspect of the present invention relates to a method of kinetic resolution, comprising the step of reacting racemic chiral alkene with a nucleophile in the presence of a derivatized quinine or quinidine.
A series of novel carbohydrate-derived thioureas were synthesized and examined as catalysts for the asymmetric Michael addition of symmetrical 1,3-dicarbonyl compounds, including dimethyl malonate, to several trans-β-nitrostyrenes. High enantioselectivities (up to 94% ee) as well as high yields (up to 98%) were attained using a bifunctional organocatalyst bearing a cinchona-based alkaloid unit.
progress has been made toward the development of metal-free catalysts of enantioselective transformations, yet the discovery of organic catalysts effective at low catalyst loadings remains a major challenge. Here we report a novel synergistic catalyst combination system consisting of a peptide-inspired chiral helical (thio)urea oligomer and a simple tertiary amine that is able to promote the Michael reaction
Highly Enantioselective Michael
Addition of Malonates to Nitroolefins Catalyzed by Chiral
Bifunctional Tertiary Amine-Thioureas Based on Saccharides
作者:Jun-An Ma、Xiao-Juan Li、Kun Liu、Hai Ma、Jing Nie
DOI:10.1055/s-0028-1087370
日期:——
A series of saccharide-derived bifunctional tertiary amine-thioureas for the asymmetric Michaeladdition reaction have been designed and synthesized. The addition products between malonates and various nitroolefins were obtained in high yields (up to 99%) and excellentenantioselectivities (up to 99% ee).
Iodine-Promoted Synthesis of 3-Arylindolizine-1-Carboxylates from 2-(2-Nitro-1-Arylethyl)Malonates and Pyridine
作者:Yun Li、Zhengquan Zhou、Weijian Ye、Juanjuan Liu、Juan Yao、Cunde Wang
DOI:10.3184/174751913x13737205567934
日期:2013.9
An efficient and straightforward one-pot synthetic protocol has been developed for the synthesis of 3-arylindolizine-1-carboxylates via 1,3-dipolar annulation of 2-(2-nitro-1-arylethyl)malonates with pyridine and subsequent aromatisation in the presence of molecular iodine. The structure of methyl 3-(4-methoxyphenyl)indolizine-1-carboxylate (2a) and methyl 3-iodo-2-(4-nitrophenyl)indolizine-1-carboxylate