The Stannum-Ene Reactions of Benzyne and Cyclohexyne with Superb Chemoselectivity for Cyclohexyne

The stannum-ene reactions of both benzyne and cyclohexyne were realized, which is particularly suitable for cyclohexyne with a broad substrate scope and excellent chemoselectivity. Our DFT calculations via distortion/interaction analysis revealed that both stannum- and hydrogen-ene reactions with cyclohexyne have later transition states due to their higher distortion energies in the transition states than those in benzyne reactions, which lead to enhanced Pauli repulsion as the decisive factor in the interaction energy accompanied with enlarged energy gap between two types of ene reactions. Therefore, excellent chemoselectivity was disclosed in the cyclohexyne-ene reaction.

Automated summary

The stannum-ene reactions of benzyne and cyclohexyne were successfully achieved, with cyclohexyne demonstrating a wide substrate scope and excellent chemoselectivity. DFT calculations revealed that the transition states of the stannum- and hydrogen-ene reactions with cyclohexyne occurred later due to higher distortion energies, resulting in enhanced Pauli repulsion and increased energy gap between the two types of ene reactions, leading to excellent chemoselectivity.