Asymmetric Sulfa-Michael Addition of α,β-Unsaturated Esters/Amides Using a Chiral N-Heterocyclic Carbene as a Noncovalent Organocatalyst
作者:Jiean Chen、Yong Huang、Pengfei Yuan、Sixuan Meng
DOI:10.1055/s-0035-1561843
日期:——
We report an asymmetric sulfa-Michael reaction of α,β-unsaturated amides and estersusing a chiral N-heterocyclic carbene as the HOMO-raising organocatalyst. We discovered an interesting correlation between 13C NMR shifts of substrates and ee of their products. More electron-deficient Michael acceptors afforded higher enantioselectivity.
我们报告了使用手性 N-杂环卡宾作为 HOMO 提升有机催化剂的 α,β-不饱和酰胺和酯的不对称磺胺-迈克尔反应。我们发现底物的 13C NMR 位移与其产物的 ee 之间存在有趣的相关性。更多缺电子迈克尔受体提供更高的对映选择性。
Conjugate Addition of Lithium <i>N</i>-Phenyl-<i>N</i>-(α-methylbenzyl)amide: Application to the Asymmetric Synthesis of (<i>R</i>)-(−)-Angustureine
作者:Scott A. Bentley、Stephen G. Davies、James A. Lee、Paul M. Roberts、James E. Thomson
DOI:10.1021/ol200625h
日期:2011.5.20
The conjugate addition of lithium (R)-N-phenyl-N-(α-methylbenzyl)amide to a range of α,β-unsaturated 4-methoxyphenyl esters proceeds with excellent levels of diastereoselectivity to give the corresponding β-amino esters in good yield and as single diastereoisomers (>99:1 dr). The synthetic utility of this methodology has been demonstrated via the short and concise asymmetricsynthesis of the tetrahydroquinoline