Facile C−N Cleavage in a Series of Bridged Lactams

A series of strained bi- and tricyclic amides has been shown to be unusually sensitive to cleavage of the C−N bond adjacent to the amide moiety. This bond undergoes facile breaking when subjected to treatment with H2/Pd(OH)2, MeI, and DDQ. In each case, the reaction is highly regioselective and mainly results in breaking the C−N bond that deviates the farthest from its natural planar state. Preliminary experiments that bear on the mechanisms of these reactions are described.