Hetero-cope rearrangements of nitrosobutenes. DFT studies of thermal and acid-catalyzed reactions

Org Lett. 2006 Dec 21;8(26):5975-8. doi: 10.1021/ol062454s.

Abstract

[Structure: see text] Density functional theory studies of the hetero-Cope reactions of 4-nitroso-1-butenes and nitrosobicyclo[2.2.2]hexenes are reported. The reactions proceed via concerted mechanisms. The electron-withdrawing methoxycarbonyl group alpha- to the nitroso group decreases the activation barrier. Lewis acids such as SbF5 and TiCl4 accelerate the reactions, as has been found experimentally by Zakarian and Lu.