Carbon–carbon bond formation via benzoyl umpolung attained by photoinduced electron-transfer with benzimidazolines
作者:Tomohito Igarashi、Eiji Tayama、Hajime Iwamoto、Eietsu Hasegawa
DOI:10.1016/j.tetlet.2013.10.028
日期:2013.12
A photoreaction between benzoyl compounds, such as benzoylformate derivatives, and 2-(p-anisyl)-1,3-dimethylbenzimidazoline in the presence of allyl bromide was found to give various allylated alcohols. In the reaction of benzoylformates, α-hydroxy ester enolates, for which the negative charge occurs on the carbonyl carbon of benzoyl (umpolung reactivity), are proposed to be generated as intermediates
发现在烯丙基溴的存在下,苯甲酰基化合物如苯甲酰基甲酸酯衍生物与2-(对茴香基)-1,3-二甲基苯并咪唑啉之间的光反应产生了各种烯丙基化的醇。在苯甲酰基甲酸酯的反应中,建议通过苯并咪唑啉向光激发的苯甲酰基甲酸酯的电子转移,作为中间体生成α-羟基酯烯酸酯,其在苯甲酰基的羰基碳上带有负电荷。这些物质与烯丙基溴反应生成α-烯丙基-α-羟基酯。