Pd(0)-catalyzed atom transfer radical cyclization of N-allyl-α-chloroamides: highly stereoselective synthesis of substituted γ-lactam
摘要:
A catalysis system comprised of Pd(cod)Cl-2 precursor and IMes ligand has been developed, which is efficient to catalyze the atom transfer radical cyclization of N-allyl-alpha-chloroamides with the help of NaI additive. This reaction provides a facile access to beta-iodomethyl-gamma-lactam with high stereoselectivity. Moreover, the results from the reaction of deuterium-labeled substrate and TEMPO-trapping experiment clearly indicate that radical intermediate(s) should be involved in the reaction. (C) 2015 Elsevier Ltd. All rights reserved.