Chiral Lewis Base Catalyzed Enantioselective Selenocyclization of 1,1-Disubstituted Alkenes: Asymmetric Synthesis of Selenium-Containing 4H-3,1-Benzoxazines

An enantioselective selenocyclization of 1,1-disubstituted alkenes was achieved for the first time, which is enabled by a novel combination of a chiral BINAM-derived sulfide and an achiral Lewis acid. Various seleniumcontaining 4H-3,1-benzoxazines, which are widely present in a range of medicinally relevant molecules, were readily obtained in moderate to good yields and good to excellent enantioselectivities. A series of tetrasubstituted carbon stereocenters were facilely constructed.

Automated summary

An enantioselective selenocyclization of 1,1-disubstituted alkenes was achieved for the first time using a novel combination of a chiral BINAM-derived sulfide and an achiral Lewis acid. Various selenium-containing 4H-3,1-benzoxazines, which are found in many medicinally relevant molecules, were synthesized in moderate to good yields and good to excellent enantioselectivities. The reaction also facilitated the construction of tetrasubstituted carbon stereocenters.