Ambient temperature synthesis of high enantiopurity N-protected peptidyl ketones by peptidyl thiol ester-boronic acid cross-coupling.

ABSTRACT: alpha-Amino acid thiol esters derived from N-protected mono-, di-, and tripeptides couple with aryl, pi-electron-rich heteroaryl, or alkenyl boronic acids in the presence of stoichiometric Cu(I) thiophene-2-carboxylate and catalytic Pd(2)(dba)(3)/triethylphosphite to generate the corresponding N-protected peptidyl ketones in good-to-excellent yields and in high enantiopurity. Triethylphosphite plays a key role as a supporting ligand by mitigating an undesired palladium-catalyzed decarbonylation-beta-elimination of the alpha-amino thiol esters. The peptidyl ketone synthesis proceeds at room temperature under nonbasic conditions and demonstrates a high tolerance to functionality.

SUBMITTER: Yang H 

PROVIDER: S-EPMC2652697 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature