Unusual rearrangement and dearomatization reactions in Cu(I)-catalyzed atom transfer radical cyclizations from N-(1-phenylethyl)trichloroacetamides

Abstract

Atom transfer radical cyclization of N-(α-methyl)benzyl substituted trichloroacetamide upon α,β-unsaturated nitriles in compounds 1, using CuCl, trispyridylmethylamine (TPMA), and AIBN as a reducing agent, gives morphan derivatives (2 and 3) and the unusual normorphans 4 and 5, as well as the unexpected azaspirodecanes 6. Stereospecific formation of normorphans involves memory of chirality in the cyclization step and azaspirodecanes are generated by a radical dearomative ipsocyclization followed by a radical dimerization.