Synthesis of 2,4,5-Trisubstituted Oxazoles from Copper-Mediated Benzylic sp3 C–H Aerobic Oxidative Annulation of Ketones and Amines via a Cascade Reaction
- 27 December 2022
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 88 (2) , 1227-1234
Abstract
The functionalization of sp3 carbons is deemed challenging in synthetic organic chemistry yet has tremendous potential in producing potent organic compounds. A facile synthesis of 2,4,5-trisubstituted oxazoles through an oxidative, copper-catalyzed, and solvent-free annulation is described. Various arylated oxazoles were efficaciously synthesized at a mild temperature from readily available substrates under a molecular oxygen atmosphere. Preliminary mechanistic studies suggested that the reaction proceeds via an anionic-type mechanism and indicated the formation of a keto-imine intermediate. The reaction is notable for the abstraction of six hydrogen atoms, the functionalization of one sp2 carbon and two sp3 carbons, and the formation of C-O and C-N bonds.Keywords
Funding Information
- South African Agency for Science and Technology Advancement (TTK180410319052)
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