SmI2-Mediated Radical Cyclizations Directed by a C−Si Bond
摘要:
The use of a silicon stereocontrol element in cyclobutanol and cyclopentanol-forming cyclizations mediated by SmI2 results in excellent diastereocontrol. The C-Si bond in the products of cyclization provides a versatile handle for further manipulation. An asymmetric route to cyclization substrates involving copper-catalyzed silyl transfer has also been developed.
Cu(I)–NHC Catalyzed Asymmetric Silyl Transfer to Unsaturated Lactams and Amides
摘要:
The first asymmetric silylation of unsaturated lactams and amides using Cu(I)-NHC catalysts and PhMe(2)SiBpin has been accomplished. The method has been exploited in an expedient asymmetric synthesis of the (R)-enantiomer of the nootropic drug oxiracetam.