Synthesis of 3-aryl-3-benzazepines via aryne [1,2] Stevens rearrangement of 1,2,3,4-tetrahydroisoquinolines

An efficient method for the synthesis of 3-aryl-3-benzazepines via aryne induced [1,2] Stevens rearrangement of 1,2,3,4-tetrahydroisoquinolines is described. This approach provided straightforward access to 3-aryl-3-benzazepines in moderate to good yields under transition-metal-free and strong-base-free conditions. Temperature-dependent α-arylated products of the carbonyl group were also obtained. Preliminary mechanistic studies suggest both 3-aryl-3-benzazepines and α-arylated products of the carbonyl group were generated via the rearrangement of nitrogen ylide intermediates.