Asymmetric vinylogous Michael reaction of α,β-unsaturated ketones with γ-butenolide under multifunctional catalysis
作者:Huicai Huang、Feng Yu、Zhichao Jin、Wenjun Li、Wenbin Wu、Xinmiao Liang、Jinxing Ye
DOI:10.1039/c0cc01054e
日期:——
general and directorganocatalytic asymmetric vinylogousMichael reaction of gamma-butenolide with alpha,beta-unsaturated ketones was investigated with a multifunctional primary amine salt as catalyst. The reaction enables straightforward access toward synthetically versatile gamma-substituted butenolides from simple 2(5H)-furanone with satisfactory yields, diastereo- and enantioselectivities (up to 30:1
Expedite Protocol for Construction of Chiral Regioselectively N-Protected Monosubstituted Piperazine, 1,4-Diazepane, and 1,4-Diazocane Building Blocks
作者:François Crestey、Matthias Witt、Jerzy W. Jaroszewski、Henrik Franzyk
DOI:10.1021/jo900441s
日期:2009.8.7
This paper describes the first study of solution-phase synthesis of chiral monosubstituted piperazine building blocks from nosylamide-activated aziridines. The protocol, involving aminolysis of the starting aziridines with omega-amino alcohols and subsequent Fukuyama-Mitsunobu cyclization, offers the advantage of mild conditions as well as short reaction times, and it leads to optically Pure N-Boc- or N-Ns-protected piperazines. This four-step sequence, requiring only a single final chromatographic purification, was extended to include novel diazepane and diazocane derivatives.