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Updated: Jul 6, 2026

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
The Newman-Kwart rearrangement: a microwave kinetic study
John P Gilday1, Philip Lenden, Jonathan D Moseley
1AstraZeneca, Process Research and Development, Avlon Works, Severn Road, Hallen, Bristol, BS10 7ZE, UK.
Abstract:
The kinetic profile of the Newman-Kwart rearrangement has been evaluated using microwave heating. After first demonstrating equivalence between conventional convective heating and microwave heating, data was gathered and analyzed to determine the effects of substituent, solvent, and concentration on the reaction order. Reaction rate constants, Arrhenius constants, and activation energies have been determined. The reaction rate shows strong sensitivity to the substituent and modest sensitivity to the solvent. At high concentrations, the reaction order increases from the previously reported first-order to a mixed first/second-order reaction. Overall, this re-evaluation of the Newman-Kwart rearrangement has shown the reaction rate order to be more complex than previously thought. In addition, microwave heating has proven ideal for the rapid collection of data to facilitate this type of kinetic study.
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