Highly Regioselective Amination of Unactivated Alkanes by Hypervalent Sulfonylimino-lambda(3)-Bromane

作者:Ochiai Masahito*; Miyamoto Kazunori; Kaneaki Takao; Hayashi Satoko; Nakanishi Waro
来源:Science, 2011, 332(6028): 448-451.
DOI:10.1126/science.1201686

摘要

Amination of alkanes has generally required metal catalysts and/or high temperatures. Here we report that simple exposure of a broad range of alkanes to N-triflylimino-lambda(3)-bromane 1 at ambient temperature results in C-H insertion of the nitrogen functionality to afford triflyl-substituted amines in moderate to high yields. Marked selectivity for tertiary over secondary C-H bonds was observed; primary (methyl) C-H bonds were inert. Addition of hexafluoroisopropanol to inhibit decomposition of 1 dramatically improved the C-H amination efficiencies. Second-order kinetics, activation parameters (negative activation entropy), deuterium isotope effects, and theoretical calculations suggest a concerted asynchronous bimolecular transition state for the metal-free C-H amination event.

  • 出版日期2011-4-22