Diastereo- and Enantioselective Synthesis of Oxazine and Oxazolidine Derivatives with a Chiral Quaternary Carbon Center under Multifunctional Catalysis

An easy one-pot, multistep cascade reaction which could afford a series of substituted benzo[d]pyrido[2,1-b]oxazolidine and [1,3]oxazine derivatives in a highly enantio- (up to 98% ee) and diastereoselective (4:1 to >20:1 dr) manner with generally good to excellent yields (up to 99%) has been developed. This well designed strategy could be applied to a wide scope of substrates under mild conditions with simple operations.