Theoretical insight into the mechanism of palladium-catalyzed oxidative cascade reaction of phenylacetylene and allenes with different assisting groups

The reaction mechanisms of the palladium-catalyzed oxidative cascade reaction of phenylacetylene and allenes with different assisting groups have been theoretically investigated with the aid of density func-tional theory calculations (DFT) calculations. Both reactions A (Pd(OAc)(2)-catalyzed cascade reactions of phenylacetylene with the allene bearing hydroxyl group) and B (Pd(OAc)(2)-catalyzed cascade reactions of phenylacetylene with the allene bearing p-toluenesulfonamide) involve sp(3) C -H activation processes, but the specific reaction mechanism is different due to allenes bearing different alpha-nucleophilic functionality in the substrate. On the basis of these mechanistic foundations, the influence of electronic effect and steric effect on chemoselectivity was illustrated. The present study provided more universal and deeper mechanistic insights into Pd-catalyzed oxidative cascade reaction of phenylacetylene and allenes with different alpha-nucleophilic functionality (e.g., OH, NHR). (C) 2022 Elsevier B.V. All rights reserved.