A new Brønsted acid derived from squaric acid and its application to Mukaiyama aldol and Michael reactions
作者:Cheol Hong Cheon、Hisashi Yamamoto
DOI:10.1016/j.tetlet.2009.03.060
日期:2009.7
of silyl enol ether. The Brønsted acid was further applied to Mukaiyama Michael reaction of α,β-unsaturated ketones. It is noted that catalyst loading of all Mukaiyama reactions was only 1 mol % or less, which demonstrated the high reactivity of this acid. Mechanistic studies implied that the Mukaiyama aldol reaction might proceed through Brønsted acid catalysis, rather than through Lewis acid catalysis
双ñ制备了三稳定的强布朗斯台德酸-三氟甲磺酰基方酸酰胺,并将其用于布朗斯台德酸催化的甲硅烷基烯醇醚的Mukaiyama醇醛和迈克尔反应。以定量收率获得了所得的Mukaiyama醛醛缩醛产品,而该Brønsted酸在酮类中的用途扩展仅限于缺电子的酮类,这可能是由于酮的反应性较低以及甲硅烷基烯醇醚的竞争性去甲硅烷基化。将布朗斯台德酸进一步用于α,β-不饱和酮的Mukaiyama Michael反应。值得注意的是,所有Mukaiyama反应的催化剂负载量仅为1mol%或更低,这表明该酸具有高反应性。机理研究表明,Mukaiyama aldol反应可能会通过Brønsted酸催化进行,