title: Sulfonamide-promoted palladium(II)-catalyzed alkylation of unactivated methylene C(sp3)-H bonds with alkyl iodides.
abstract: The alkylation of unactivated β-methylene C(sp(3))-H bonds of α-amino acid substrates with a broad range of alkyl iodides using Pd(OAc)2 as the catalyst is described. The addition of NaOCN and 4-Cl-C6H4SO2NH2 was found to be crucial for the success of this transformation. The reaction is compatible with a diverse array of functional groups and proceeds with high diastereoselectivity. Furthermore, various β,β-hetero-dialkyl- and β-alkyl-β-aryl-α-amino acids were prepared by sequential C(sp(3))-H functionalization of an alanine-derived substrate, thus providing a versatile strategy for the stereoselective synthesis of unnatural β-disubstituted α-amino acids.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027 (China).
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Bing-Feng
authors.initials: BF
authors.lastname: Shi
keywords: CH activation; alkylation; amino acids; palladium; synthetic methods