Organic Chemistry Portal

Abstracts

Search:

The Newman-Kwart Rearrangement of O-Aryl Thiocarbamates: Substantial Reduction in Reaction Temperatures through Palladium Catalysis

Jeremy N. Harvey, Jesús Jover, Guy C. Lloyd-Jones*, Jonathan D. Moseley, Paul Murray, Joseph S. Renny

*School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK), Email: guy.lloyd-jonesbris.ac.uk

J. N. Harvey, J. Jover, G. C. Lloyd-Jones, J. D. Moseley, P. Murray, J. S. Renny, Angew. Chem. Int. Ed., 2009, 48, 7612-7615.

DOI: 10.1002/anie.200903908 (free Supporting Information)


Abstract

The Newman-Kwart rearrangement normally requires high temperatures (200-300°C), but in the presence of Pd(PtBu)2 proceeds smothly at 100°C with a range of substrates. The reaction proceeds through a five-centred Pd-S coordinated oxidative addition, with intermolecular exchange of aryl and thiocarbamate moieties through dimerization of the resting state

see article for more examples

Working model for Pd-catalyzed NKR of 1a to 2a. Numbers in parenthesis are DFT-derived ZPE corrected energies in kcal • mol-1
Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.



Key Words

Newman-Kwart Rearrangement, homogeneous catalysis, palladium, reaction mechanism, rearrangement, sulfur compounds


ID: J06-Y2009-0970