Highly Active Monoligated Arylpalladacyles for Cross-Coupling Reactions

• Published in: Organic process research & development Vol. 23; no. 10; pp. 2181 - 2190
• Main Authors: Zhang, Chunming, Ogawa, Kelli, Tu, Siyu, Zu, Chengli, Ringer, Jim, Derstine, Chris, Do, Hien, Fontaine, Philip P, Klosin, Jerzy
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.10.2019
• Subjects: monoligated palladium complex; Suzuki−Miyaura cross-coupling; phosphane ligands; C−C coupling; arylpalladacycles
• ISSN: 1083-6160; 1520-586X
• DOI: 10.1021/acs.oprd.9b00234

A series of new monoligated arylpalladacyclic complexes with amide, urea, and carbamate frameworks have been developed and were found to be highly active for Suzuki–Miyaura cross-couplings. These palladacycle precatalysts are derived from simple, inexpensive starting materials and are air- and moisture-stable. The most active congeners among those tested are the urea-based palladacycles, which in conjunction with a tBu3P ligand induce high conversions for a range of aryl halide and boronate coupling partners. Notably, aryl chlorides are viable coupling partners even under relatively mild conditions at short reaction times (e.g., 1 h at 60 °C). One of the best catalysts described here exhibits improved turnover frequency for a particularly difficult coupling reaction involving an aryl chloride and a sterically congested boronic ester.