Effective and recyclable dendritic catalysts for the direct asymmetric Michael addition of aldehydes to nitrostyrenes
作者:Yawen Li、Xin-Yuan Liu、Gang Zhao
DOI:10.1016/j.tetasy.2006.07.004
日期:2006.8
Direct catalytic enantio- and diastereoselective Michael addition reaction of aldehydes to nitrostyrenes is described using a series of recyclable chiral 2-trimethylsilanyloxy-methyl-pyrrolidine-based dendritic catalysts. Good yields (up to 82%), and high diastereoselectivities (up to syn/anti = 95/5) and enantioselectivities (up to 99% ee) have been obtained.
使用一系列可循环使用的手性2-三甲基甲硅烷基氧基-甲基-吡咯烷基树枝状催化剂描述了醛与硝基苯乙烯的直接催化对映和非对映选择性迈克尔加成反应。获得了良好的收率(高达82%),高的非对映选择性(高达syn / anti = 95/5)和对映选择性(高达99%ee)。
4,4′-Disubstituted-L-proline Catalyzes the Direct Asymmetric Michael Addition of Aldehydes to Nitrostyrenes
作者:Liu-qun Gu、Gang Zhao
DOI:10.1002/adsc.200600640
日期:2007.7.2
In a search for small organic molecules as catalysts for the directasymmetricMichaeladdition reaction of aldehydes to nitrostyrenes, 4,4′-di(naphthalene-1-ylmethyl)-L-proline 1c and a catalytic amount of 4-dimethylaminopyridine (DMAP) were found to be an efficient system for the Michaeladdition of aldehydes to nitrostyrenes with high diastereo- and enantioselectivity and broad substrate range.
Efficient and Highly Enantioselective Michael Addition of Aldehydes to Nitroalkenes Catalyzed by a Surfactant-type Organocatalyst in the Presence of Water
silyl ether organocatalyst bearing a long chain only in 2 mol % loading could catalyze the asymmetric Michael reaction of various aldehydes with trans-nitroalkenes at room temperature in the presence of water, giving the desired adducts in excellent yields with high diastereoselectivities and excellent enantioselectivities (up to >99% ee).
Betancort, Juan M.; Sakthivel, Kandasamy; Thayumanavan, Rajeswari, Synthesis, 2004, # 9, p. 1509 - 1521
作者:Betancort, Juan M.、Sakthivel, Kandasamy、Thayumanavan, Rajeswari、Tanaka, Fujie、Barbas III, Carlos F.
DOI:——
日期:——
Catalytic Direct Asymmetric Michael Reactions: Taming Naked Aldehyde Donors
作者:Juan M. Betancort、Carlos F. Barbas
DOI:10.1021/ol0167006
日期:2001.11.1
[GRAPHICS]Direct catalytic enantio- and diastereoselective Michael addition reactions of unmodified aldehydes to nitro olefins using (S)-2-(morpholinomethyl)-pyrrolidine as a catalyst are described. The reactions proceed in good yield (up to 96%) in a highly syn-selective manner (up to 98:2) with enantloselectivities approaching 80%. The resulting gamma -formyl nitro compounds are readily converted to chiral, nonracemic 3,4-disubstituted pyrrolidines.