<i>N</i>-Heterocyclic Carbene/Lewis Acid Dual Catalysis for the Divergent Construction of Enantiopure Bridged Lactones and Fused Indenes
作者:Zhan-Yong Wang、Ya-Li Ding、Shi-Ning Li、Ying Cheng
DOI:10.1021/acs.joc.6b02329
日期:2016.12.2
The chiral triazole carbene and Ti(OPr-i)4 cocatalyzed reaction between α,β-unsaturated aldehydes and 2-(aroylvinyl)benzaldehydes was systematically studied. A divergence in reaction pathways was observed under different reaction conditions. In benzene solvent and at ambient temperature, the reaction produced 4,5-dihydro-1,4-methanobenzo[c]oxepin-3-ones, the bridged caprolactones, as the major products
系统地研究了α,β-不饱和醛与2-(芳酰基乙烯基)苯甲醛之间的手性三唑卡宾和Ti(OPr- i)4共催化反应。在不同的反应条件下,观察到了反应途径的差异。在苯溶剂中和在环境温度下,该反应以适中的收率和出色的对映选择性产生了主要产物4,5-二氢-1,4-甲氧基苯并[ c ] oxepin -3-ones,桥联己内酯。然而,在二氯乙烷中和在50°C下进行相同的反应,得到2,8-二氢环戊[ a在大多数情况下,]茚是主要产品。通过将桥接的内酯产物转化为对映体纯的4-羟基-1,2,3,4-四氢萘-2-羧酸,证明了所开发方法的应用。