On the Mechanism of Pd(0)-Catalyzed, Cu(I) Carboxylate-Mediated Thioorganic-Boronic Acid Desulfitative Coupling. A Non-innocent Role for Carboxylate Ligand

• Authors: Jamal Musaev, Emory University; Lanny S Liebeskind, Emory University
• Journal Title: Organometallics
• Volume: Volume 28, Number 16
• Publisher: American Chemical Society | 2009-07-22, Pages 4639-4642
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1021/om900602b
• Subjects: Chemistry, General
• Keywords: Cu(I) carboxylate; density functional calculations; transmetalation; thioorganic-boronic acid coupling; non-innocent carboxylate

Abstract

Computational studies of the mechanism of the Pd-catalyzed, Cu(I)-carboxylate-mediated desulfitative coupling of thioorganics with boronic acids have determined that the requisite Cu(I)-carboxylate plays multiple important roles. The Cu(I)-carboxylate enhances both the transmetalation and the C-C reductive elimination steps: it acts as a reactive transmetalation center and it provides a vital carboxylate ligand. The carboxylate ligand functions not only as an activator for the boronic acid, but it also displaces a phosphine ligand at the palladium center generating a catalytically competent mono-phosphine-palladium intermediate.