Divergent NHC-Catalyzed Oxidative Transformations of 3-Bromoenal: Selective Synthesis of 2<i>H</i>-Pyran-2-ones and Chiral Dihydropyranones
作者:Gang Wang、Xia Chen、Gaohan Miao、Weijun Yao、Cheng Ma
DOI:10.1021/jo400950j
日期:2013.6.21
A selective synthesis of either 2H-pyran-2-ones (4) or chiral dihydropyranones (6) from the same substrates of 3-bromoenals and 1,3-dicarbonyl compounds upon oxidative N-heterocyclic carbene catalysis is presented. It is shown that the oxidative transformation of 3-bromoenals under NHC catalyst can be well controlled to proceed through two pathways, i.e., elimination of reducible β-bromide or by an
提出了在氧化的N-杂环卡宾催化下,由3-溴烯醛和1,3-二羰基化合物的相同底物选择性合成2 H-吡喃-2-酮(4)或手性二氢吡喃酮(6)的方法。结果表明,可以很好地控制NHC催化剂下3-溴烯醛的氧化转化,通过两条途径进行,即消除可还原的β-溴化物或通过外部氧化剂3进行,从而选择性地产生两种不饱和酰基偶氮,分别。