70. Insights into complicated Au(I)-catalyzed polycycloisomerization driven by strain release: A DFT study

Xin, W.; Bi, S.*; Zhang, W.; Hu, J.; Jiang, Y.; Yuan, X.-A. Mol. Catal. 2022, 518, 112082. Download Link

Abstract: The complicated Au(I)-catalyzed polycycloisomerization driven by strain release was explored theoretically with the aid of density functional theory calculations. Mechanistic study shows the reaction first generates an organic intermediate (a bicycle[4.2.0] diene) through Au(I)-induced yne‑ene cyclization, ring expansion and 1,2-H shift. After again yne‑ene cyclization and 1,2-alkyl shift from the LAu-coordinated bicycle[4.2.0] diene, the reaction was found to undergo 1,2-AuL shift rather than NTf2-assisted deprotonation to finally furnish the product. Formation of the organic intermediate was indicated to be rate-determinant. Based on the aforementioned ratedeterminant process, the influence of substituents on product yields was reasonably rationalized. In addition, a catalytic process seperation was predicted to be involved. The approach provided in this work to identify a process seperation or a non-process seperation would be extended to other one-pot catalytic tandem reactions.