A series of new modular bifunctional chiral thiourea organocatalysts were synthesized from natural Cinchona alkaloids and amino acids, and their performance in the aza-Henry reaction of nitroalkanes to imines, the Michaeladdition of acetylacetone to nitroolefins and the Michaeladdition of acetone to nitroolefins was investigated. Under the mild conditions, the important building blocks β-nitro amines
Novel bifunctional thiourea–ammonium salt catalysts derived from amino acids: application to highly enantio- and diastereoselective aza-Henry reaction
作者:Hong-Yu Wang、Zhuo Chai、Gang Zhao
DOI:10.1016/j.tet.2013.04.079
日期:2013.6
development of new efficient and easily accessible catalysts has been one of the focuses in asymmetric phase-transfer catalysis. In this paper, a novel class of chiral bifunctional thiourea–ammonium phase-transfercatalysts were synthesized from commercially available α-amino acids. The structural modularity of these catalysts permits facile tunings to achieve optimum results, which was demonstrated
The formal addition of ammonia to nitroalkenes, affording optically active β‐amino nitro compounds in high yields and enantioselectivities, is presented (see scheme). The approach is based on a novel thiourea‐catalyzed aza‐Michael reaction, by which benzophenone imine serves as a masked ammonia equivalent, which is released by hydrolysis.
Dinuclear Zinc-AzePhenol Catalyzed Asymmetric Aza-Henry Reaction of <i>N</i>-Boc Imines and Nitroalkanes under Ambient Conditions
作者:Shanshan Liu、Wen-Chao Gao、Yu-Hang Miao、Min-Can Wang
DOI:10.1021/acs.joc.8b02943
日期:2019.3.1
asymmetric aza-Henryreaction of N-Boc imines and nitroalkanes was realized in the presence of 10 mol % dinuclear zinc-AzePhenol catalysts under ambient conditions. A variety of nitroamines were obtained in good yields (up to 97%) with excellent enantioselectivities (up to 99% ee) and high diasteroselectivity (up to 14:1 dr). Our protocol combined the operational simplicity and mild reaction conditions
作者:Xianxing Jiang、Yifu Zhang、Lipeng Wu、Gen Zhang、Xing Liu、Hailong Zhang、Dan Fu、Rui Wang
DOI:10.1002/adsc.200900413
日期:2009.9
doubly stereocontrolled organocatalytic aza-Henry reaction of nitroalkanes to N-Boc-imines generated in situfrom a variety of substituted α-amidosulfones was investigated for the first time, in general, affording the corresponding products with high to excellent yields (up to 93% yield) and enantioselectivities (up to 98% ee), and satisfactory diastereoselectivies (anti/syn up to 98:2). Furthermore