The mechanism and “silver effect” in regiodivergent gold-catalyzed hydroamination of terminal alkynyl sulfamides have been explored by the density functional theory (DFT) in the model systems composed of [AuCl(Ph₃P)]/AgOTf (series A), AuCl(Ph₃P)]/K₂CO₃ (series B) and [AuCl(Ph₃P)]/Ag₂CO₃ (series C). Our results clearly showed that the regioselectivity of the terminal alkynyl sulfamides is mainly controlled by true involvement of Ag in the catalysis when using different silver salts as a component of gold-based catalytic system, rather than the steric effect. In the [AuCl(Ph₃P)]/AgOTf and [AuCl(Ph₃P)]/Ag₂CO₃ catalytic systems, the formation of π-activation or σ-gold-π-silver intermediates turns more favorable the 6-endo-dig cyclization in comparison with the 5-exo-dig pathway. On the other hand, the 5-exo-dig cyclization involving a three-membered Au-C-Au ring activated alkyne intermediate is likely the major pathway for the [AuCl(Ph₃P)]/K₂CO₃ catalytic system. Furthermore, the regioselectivity and its origin as well as the rationalization of “silver effect” are also examined and discussed in detail.

在[AuCl（Ph ₃ P）] / AgOTf（系列A），AuCl组成的模型系统中，通过密度泛函理论（DFT）探索了区域发散金催化的末端炔基磺酰胺加氢胺化的机理和“银效应”。（Ph ₃ P）] / K ₂ CO ₃（B系列）和[AuCl（Ph ₃ P）] / Ag ₂ CO ₃（C系列）。我们的结果清楚地表明，当使用不同的银盐作为金基催化体系的组分时，末端炔基磺酰胺的区域选择性主要受Ag真正参与催化的控制，而不是空间效应。在[AuCl（Ph₃ P）] / AgOTf和[AuCl（Ph ₃ P）] / Ag ₂ CO ₃催化体系，形成π-活化或σ-金-π-银中间产物相比，更有利于6-内-挖-环化与5-exo-dig途径。另一方面，涉及三元Au-C-Au环活化炔烃中间体的5-exo-dig环化反应可能是[AuCl（Ph ₃ P）] / K ₂ CO ₃催化系统的主要途径。此外，还对区域选择性及其起源以及“银效应”的合理化进行了详细的讨论。