Catalytic Synthesis of Dibenzazepines and Dibenzazocines by 7-Exo- and 8-Endo-Dig-Selective Cycloisomerization

The 7-exo- and 8-endo-dig-selective gold-catalyzed cycloisomerizations of 2-propargylamino biphenyl derivatives were developed. The reaction of terminal alkynes gave dibenzo[b,d]azepines by 7-exo-dig cycloisomerization. In contrast, when internal alkynes were subjected to the reaction, 8-endo-dig cycloisomerization proceeded to provide dibenzo[b,d]azocines. The nucleophilicity at the reaction site and the electron-withdrawing effect of a tosyl group were important for the present selective transformation. This protocol could be used for ynamide substrates and a silver-catalyzed reaction gave 7-exo-dig products selectively.

Automated summary

The study developed gold-catalyzed 7-exo- and 8-endo-dig-selective cycloisomerizations, providing different compounds based on the nucleophilicity and electron-withdrawing effect during the reactions. Additionally, the method could be extended to ynamide substrates with silver-catalyzed reactions yielding 7-exo-dig products selectively.