Alkyne Migratory Insertion Enabled Dynamic Kinetic Asymmetric Dearomatization of Unactivated Racemic Biaryls.

Abstract

Catalytic asymmetric dearomatization has emerged as an effective approach for transforming planar aromatic compounds into valuable three-dimensional chiral architectures. Herein, we report a palladium-catalyzed enantioconvergent dearomatization of non-activated naphthalene derivatives via alkyne migratory insertion. Unlike existing methods that convert racemic biaryl substrates into enantiopure compounds, this work represents a rare strategy for dynamic kinetic asymmetric dearomatization of racemic unactivated biaryl systems. A custom-designed asymmetric polyfluorinated phosphoramidite ligand enables high reactivity and stereocontrol. Mechanistic studies confirmed an enantioconvergent pathway, converting configurationally labile biaryl substrates into enantioenriched spiro frameworks. A linear correlation between product and ligand enantiopurity supports a 1:1 Pd/ligand ratio in the active catalytic species, with density functional theory calculations offering further mechanistic insight. The synthetic utility was further demonstrated through scale-up reactions and downstream derivatizations, including a central-to-axial chirality transfer process.