Aminocatalyzed Synthesis of Enantioenriched Phenalene Skeletons through a Friedel–Crafts/Cyclization Strategy

A series
of enantioenriched phenalene-derived compounds were accessed
by a Friedel–Crafts/cyclization strategy. Starting from α,β-unsaturated
aldehydes and 2-naphthol derivatives, high levels of enantioselectivity
were obtained through iminium–enamine catalysis. The catalytic
system composed of a diphenylprolinol silyl ether organocatalyst and
triethylamine as a base was applied to a combination of diversely
functionalized substrates. The obtained phenalene-derived architectures
are promising building blocks for reaching natural products and exhibit
fluorescence properties.

本研究通过傅-克（Friedel–Crafts）/环化策略，合成了一系列对映体富集的非那烯（phenalene）衍生化合物。以α,β-不饱和醛与2-萘酚衍生物为起始原料，借助亚胺-烯胺（iminium–enamine）催化体系，可获得高对映选择性的目标产物。该催化体系由二苯脯氨醇硅醚有机催化剂与作为碱的三乙胺组成，可适配多种不同官能化的底物。所得到的非那烯衍生分子骨架是制备天然产物的极具潜力的结构砌块，同时还展现出荧光特性。