Organocatalytic Activation of Alkynes Enabled Remote Control of Atroposelectivity via Vinylidene para-Quinone Methides

Axially chiral o-VQMs have been extensively investigated as key intermediates to approach miscellaneous chiral structures. By sharp contrast, their structural isomers p-VQMs have not been previously documented. The major reason, which results in the significant delay, may ascribe to the inherent challenges in the enantioselective activation of alkynes in a remote manner. Herein, we demonstrate that the remote activation mechanism of para-hydroxyl-substituted arylacetylenes enables significant stereochemical induction, resulting in axially chiral aryl-alkenes with excellent enantiopurities. A series of control experiments are performed to elucidate the insights of this asymmetric transformation and to verify the involvement of multimolecular CPAs in the reaction process. These findings are expected to unlock a new feature for VQM chemistry and inspire investigation into the organocatalytic remote control of stereoselectivity.