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.
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