Silicon-mediated enantioselective synthesis of structurally diverseα-amino acid derivatives

The catalytic asymmetric synthesis of novel and chiral amino acid derivatives with unconventional chemo-,diastereo-,and enantio-selectivity remains a paramount challenge.Herein we reported a novel protocol for the use of highly enantioselective copper-catalyzed cycloaddition ofα,β-unsaturated acylsilanes as a springboard reaction for the facile synthesis of structurally diversified pyrrolidines and complicatedα-amino esters by desilylation.The newly developed process could provide a wide range of synthetically useful acylsilane-substituted pyrrolidines(ASiP)in high yields and excellent diastereo-and enantioselectivities with Cu/(R)-XylBINAP complex as the catalyst.And the downstream desilylation transformation enables to expand the potntial applications of 1,3-dipolar cycloaddition in the construction of structurally unique amino acid derivatives,in which an unprecedented and concerted fluoride anion-promoted C–X(X=H,Si,N,C)bond cleavage occurred to the enantioselective construction of aldehyde-substituted pyrrolidines,linear cinnamaldehyde or alkene-substituted amino esters in high ee values.