Chiral bipyridine-annulated bicyclo[3.3.1]nonane N-oxide organocatalysts for stereoselective allylation and hydrosilylation reactions

The synthesis of chiral C-2-symmetric bis(bipyridine N,N'-dioxide) and bis(bipyridine N-monooxide) derivatives featuring bipyridine-annulated bicyclo[3.3.1 ]nonane framework is reported. The new Lewis basic bipyridine N,N'-dioxides exhibited good catalytic activity in the asymmetric allylation of aldehydes with allyltrichlorosilane, furnishing corresponding homoallylic alcohols in up to 75% ee. Reduction of ketimines and beta-enamino esters with trichlorosilane catalyzed by bipyridine N,N'-dioxides proceeded in high yields but modest enantioselectivity (38-54% ee); good levels of asymmetric induction (up to 73% ee) were attained in the reduction of alpha-imino esters at room temperature. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The newly synthesized chiral Lewis basic bipyridine N,N'-dioxides exhibited good catalytic activity in asymmetric synthesis reactions, providing high yields of target products, but the enantioselectivity needs improvement.