An Organocatalyst Bearing Stereogenic Carbon and Sulfur Centers as an Efficient Promoter for Enantioselective Hydrosilylation of 1,4-Benzooxazines

The efficient and enantioselective
hydrosilylation of 3-aryl-1,4-benzooxazines
was achieved using an l-phenyl alanine derived new Lewis
base catalyst bearing stereogenic carbon and sulfur centers. In the
presence of 2 mol % of catalyst, a broad range of 3-aryl-1,4-benzooxazines
were hydrosilylated to afford the corresponding chiral 3-aryl-3,4-dihydro-2H-1,4-benzooxazine products with good to high yields (66–98%)
and enantioselectivities (70–99% ee). This method provides
an alternative approach with great practical application potential
to access chiral 3-aryl-3,4-dihydro-2H-1,4-benzooxazines.