How Solvents Control the Chemoselectivity in Rh-Catalyzed Defluorinated [4 + 1] Annulation

Org Lett. 2021 Feb 19;23(4):1489-1494. doi: 10.1021/acs.orglett.1c00223. Epub 2021 Feb 10.

Abstract

Density functional theory calculations have been performed to reveal the chemoselectivity of Rh-catalyzed chiral C-F cleavage and γ-site functionalization. We found that the chemoselectivity is controlled by β-F elimination in methanol solvent, leading to formation of the alkynylic product. In isobutyronitrile solvent, the chemoselectivity is controlled by the allene insertion step, where the fluoroalkenylic product can be observed. The difference can be explained by analysis of the explicit solvent models.