Abstract
Catalytic, selective, and controlled oxidative functionalization of CH bonds using molecular oxygen as an oxidant remains highly desirable and equally challenging in the development of synthetic methodologies. Presented herein is a one-pot oxygenase cascade reaction wherein a copper(I)-catalyzed oxygenase reaction transforms the allylic methyl group in 3-methylidene oxindoles into an aldehyde, which then undergoes an aldol–oxa-Michael addition sequence with β-ketoesters to yield dihydrofuran-bearing oxindoles.
O2 cascades: The first one-pot oxygenase cascade is presented, wherein a copper-catalyzed oxygenase reaction transforms the allylic CH3 of 3-methylidene oxindole into an aldehyde, which then undergoes an aldol–oxa-Michael addition reaction with β-ketoesters to yield dihydrofuran-bearing oxindoles.
             
|
Electrochemical evidence that pyranopterin redox chemistry controls the catalysis of YedY, a mononuclear Mo enzyme
Hope Adamson a, Alexandr N. Simonov b, Michelina Kierzek c, Richard A. Rothery c, Joel H. Weiner c, Alan M. Bond b, and Alison Parkin a,1 a Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom; b School of Chemistry, Monash University, Clayton, VIC 3800, Australia; and c Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada Edited by Harry B. Gray, California Institute of Technology, Pasadena, CA, and approved October 13, 2015 (received for review August 25, 2015) http://www.pnas.org/content/112/47/14506.short A long-standing contradiction in the field of mononuclear Mo enzyme research is that small-molecule chemistry on active-site mimic compounds predicts ligand participation in the electron transfer reactions, but biochemical measurements only suggest metal-centered catalytic electron transfer.With the simultaneous measurement of substrate turnover and reversible electron transfer that is provided by Fourier-...