Sulfonamide-Directed Chemo- and Site-Selective Oxidative Halogenation/Amination Using Halogenating Reagents Generated in Situ from Cyclic Diacyl Peroxides
作者:Denghu Chang、Rong Zhao、Congyin Wei、Yuan Yao、Yang Liu、Lei Shi
DOI:10.1021/acs.joc.8b00243
日期:2018.3.16
The combination of cyclicdiacylperoxides with commercially available halide salts as a unique halogenating system is utilized in Hofmann–Löffler–Freytag-type reaction. This strategy allows for the formation of N-chloroamides, δ-brominated products, and even biologically relevant pyrrolidines under mild conditions in moderate to excellent yields. Meanwhile, the preliminary structure of the in situ
oxidation catalysis employing bromine has remained largely unexplored. We herein show that the combination of a tetraalkylammonium bromide and meta‐chloroperbenzoic acid offers a unique catalyst system for the convenient and selective oxidation of saturated C(sp3)−H bonds upon photochemical initiation with day light. This approach enables remote, intramolecular, position‐selective C−H amination as demonstrated
and ecologically benign alternatives to transition metals, although their application as molecular catalysts in challenging CH oxidation reactions has remained elusive. An attractive iodine oxidation catalysis is now shown to promote the convenient conversion of carbon–hydrogenbonds into carbon–nitrogen bonds with unprecedented complete selectivity. The reaction proceeds by two interlocked catalytic