Theoretical evaluation of the carbene-based site-selectivity in gold(iii)-catalyzed annulations of alkynes with anthranils†
The gold(III)-catalyzed annulations of alkynes with anthranils were evaluated using DFT calculations. A unified rationale for the Br-migration on α-imino gold(III)-carbene was proposed, from which an unprecedented “N-donation/abstraction substitution” mechanism was established using the substituted anthranils, while direct C–H nucleophilic attack was involved with the unsubstituted anthranils. The controlling factors guiding the site-selectivity were uncovered. These computational studies provide insight for developing new α-imino gold(III)-carbene mediated reactions.