Mild and Regioselective Pd(OAc)₂-Catalyzed C-H Arylation of Tryptophans by [ArN₂]X, Promoted by Tosic Acid.

ABSTRACT: A regioselective Pd-mediated C-H bond arylation methodology for tryptophans, utilizing stable aryldiazonium salts, affords C2-arylated tryptophan derivatives, in several cases quantitatively. The reactions proceed in air, without base, and at room temperature in EtOAc. The synthetic methodology has been evaluated and compared against other tryptophan derivative arylation methods using the CHEM21 green chemistry toolkit. The behavior of the Pd catalyst species has been probed in preliminary mechanistic studies, which indicate that the reaction is operating homogeneously, although Pd nanoparticles are formed during substrate turnover. The effects of these higher order Pd species on catalysis, under the reaction conditions examined, appear to be minimal: e.g., acting as a Pd reservoir in the

SUBMITTER: Reay AJ 

PROVIDER: S-EPMC5557615 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature