Enantioselective<i>N</i>-Heterocyclic Carbene-Catalyzed Michael Addition to α,β-Unsaturated Aldehydes by Redox Oxidation
作者:Zi-Qiang Rong、Min-Qiang Jia、Shu-Li You
DOI:10.1021/ol201595f
日期:2011.8.5
Enantioselective N-heterocyclic carbene-catalyzed Michael addition reactions to α,β-unsaturated aldehydes by redox oxidation were realized. With 10 mol % of camphor-derived triazolium salt D, 15 mol % of DBU, 5 mol % of NaBF4, and 100 mol % of quinone oxidant, the reactions of various dicarbonyl compounds with α,β-unsaturated aldehydes led to 3,4-dihydro-α-pyrones in good yields and excellent ee’s
对映选择性Ñ -杂环卡宾催化迈克尔加成反应的α,通过氧化还原氧化β不饱和醛分别实现。用10摩尔%的樟脑衍生的三唑盐D,15摩尔%的DBU,5摩尔%的NaBF 4和100摩尔%的醌氧化剂,各种二羰基化合物与α,β-不饱和醛的反应导致3, 4-二氢-α-吡喃酮,收率高,ee优良。