degrees , NOESY, and HeteroCOSY. Electron donating resonance and electron withdrawing inductive effect of several groups showed marked changes in chemical shifts of nuclei at the seventh positions of O-substituted quinolinols (2-15). Although in N-alkyl, 8-alkoxyquinolinium halides (16-21), ring A rightly showed low frequency chemical shift values.
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。