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 a,alpha,beta-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 properties.