Visible light bromide catalysis for oxazoline, pyrrolidine, and dihydrooxazine syntheses via Csp-H functionalizations
Navdeep Kaur1, Elizabeth C Ziegelmeyer1, Olutayo N Farinde1
1Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, Toledo, Ohio 43606, USA. wei.li@utoledo.edu.
Abstract:
A catalytic benzylic Csp-H functionalization protocol is described here. This visible light-mediated process is centered on the utilization of a bromide catalyst and oxidant to generate a nitrogen (N)-centered radical for a site-selective hydrogen atom transfer (HAT) process. This strategy enabled the unconventional syntheses of a number of N-heterocycles dependent on the amide identity. We also discovered a nucleophilicity-dependent kinetic resolution for stereochemical differentiation of Csp-H bonds that enabled the stereoselective synthesis of cis- and trans-oxazolines.
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