Stereoselective Cycloaddition of<i>N</i>-Acyliminium Ions with<i>α</i>,<i>β</i>-Unsaturated Ketones and Esters
作者:Lingfeng Qiao、Yuehua Zhou、Wei Zhang
DOI:10.1002/cjoc.201090095
日期:2010.1
β‐unsaturated ketones or esters were examined, and the dependence of these reactions on the substituents at double bonds was clarified. For β‐aryl substituted α,β‐unsaturated ketones and esters such as 4‐aryl‐3‐buten‐2‐ones, chalcones and methyl cinnamate, the [4+2] reactions could proceed smoothly at room temperature to afford 6‐acyl‐5,6,6a,11‐tetrahydroisoindolo[2,1‐a]quinolin‐11‐ones and 4‐acyl‐1
由2-芳基-3-羟基-2-,3-二氢异吲哚-1-酮或5-羟基-1-苯基-2-,5-二氢/ 2,3产生的N-酰亚胺离子的[4 + 2]反应研究了在BF 3 OEt 2存在下,与α,β-不饱和酮或酯形成的4,5-四氢吡咯-2-酮,并阐明了这些反应对双键取代基的依赖性。对于β-芳基取代的α,β-不饱和酮和酯(例如4-芳基-3-丁烯-2-酮,查耳酮和肉桂酸甲酯),[4 + 2]反应在室温下可平稳进行,得到6-酰基‐5,6,6 a,11‐四氢异吲哚[2,1‐ a〕喹啉-11酮和4 -酰基-1,3-一个,4,5-四氢吡咯并[1,2一]喹啉-1-酮或4-酰基1,2,3,3-一个,4,5-六氢吡咯并[1,2一]喹啉-1-酮在较高产率; 对于简单的α,β-不饱和酮和酯,如巴豆酸甲酯和3-甲基丁-2-烯酸乙酯,除异丁烯三醇外,[4 + 2]反应很难进行。环加成反应是高度立体选择性的,并且在每个反应中仅产生一种立体异构体。