Scandium Triflate Catalyzed Tandem Transfer Hydrogenation and Cyclization Reaction of o-Aminobenzaldehydes and o-Aminoacetophenone with Alcohols

Abstract

An effective Sc-catalyzed transfer hydrogenation and cyclization tandem reaction has been achieved. This process showed excellent functional group compatibility and good yields. A variety of benzoxazines were produced with primary or secondary alcohols as a hydrogen source. Furthermore, the utility of this newly developed protocol is demonstrated through scaled-up experiment, late-stage modification, and preliminary exploration of enantioselective synthesis.

Synthesis of quinol-type heterobiarylsviaan acid-catalyzed heteroannulation of alkynes ando-aminobenzaldehydes

“…12 Notably, o -aminobenzaldehydes without functional groups at the 3-position gave no desired products, because the self-condensation arose quickly in the presence of an acidic catalyst. 13…”