Boron-Catalyzed, Diastereo- and Enantioselective Allylation of Ketones with Allenes

The diastereo-and enantioselective allylation of ketones remains a synthetic challenge, with transition metal catalysis offering the most applied methods. Here, a boron-catalyzed allylation of ketones with allenes is presented. Excellent yield, regioselectivity, and diastereoselectivity were found across function-alized substrates. The reaction was further developed to accommodate an enantioenriched boron catalyst and thus gave asymmetric ketone allylation in good yield, diastereoselectivity, and enantioselectivity. Mechanistic studies supported a hydroboration- allylation-transborylation pathway.

Automated summary

This article presents a boron-catalyzed allylation of ketones with allenes, exploring the yield, regioselectivity, and diastereoselectivity of the reaction across functionalized substrates. Furthermore, the reaction is developed for asymmetric ketone allylation using an enantioenriched boron catalyst, achieving good yield, diastereoselectivity, and enantioselectivity. Mechanistic studies support a hydroboration-allylation-transborylation pathway.