可见光促进荧光素催化的氧化偶联反应合成苯并咪唑 [2,1-a]并异喹啉衍生物

Visible Light Promoting Fluorescein catalyzed Oxidative Coupling for the Synthesis of Benzimidazo[2,1-a]iso-quinolin-6(5H)-ones

摘要:

苯并咪唑[2,1-a]并异喹啉衍生物广泛应用于生物医药、导电材料以及高分子等领域。开发其绿色的合成新方法具有重要的意义。在室温下以N-丙烯酰胺结构为自由基受体，1,3-二氧戊烷为自由基来源，荧光素为催化剂，可见光驱动下经历自由基加成/环化反应历程制备了苯并咪唑[2,1-a]并异喹啉骨架结构。在最优反应条件下，以48%~78%收率合成了11种具有不同取代基团的苯并咪唑[2,1-a]并异喹啉衍生物，采用1H NMR、13C NMR对终产物进行了结构鉴定。

Abstract:

Benzimidazo[2,1-a]isoquinolin-6(5H)-one moieties are one of the most important compounds exten-sively existed in many pharmaceutically active compounds and functional materials. It is of great scientific significance to develop a new efficient and green method for the synthesis of benzimidazo[2,1-a]isoquinolin-6(5H)-ones. In this paper, a visible-light promoted fluoresce-in-catalyzed oxidative coupling of N-methacryloyl-2-phenylbenzoimidazole with dioxolane has been successfully developed, which underwent radical addition/ cyclization to construct benzimid-azo[2,1-a]isoquinolin-6(5H)-one derivatives. Under the optimized reaction conditions, eleven ben-zimidazo[2,1-a]isoquinolin-6(5H)-ones were obtained in 48%-78% yields. Their structures were de-termined by 1HNMR and 13CNMR. This protocal has the advantages of mild condition, green and simplicity.