Novel Sulfinamide-BasedChiral Ligand Promoted ChiralDiarylmethanol Preparation via <i>exo</i>-Directed AsymmetricC–H Alkynylation under Mild Conditions

Desymmetrization of diarylmethanols has been achieved by means of <i>exo</i>-directed Pd(II)-catalyzed C–H alkynylation under mild conditions (30 °C). We herein designed a class of chiral <i>N</i>-sulfinyl anthranilic acid (CSAA) ligands with chiral information only at the <i>N</i>-protecting group, which were found crucial for challenging stereocontrol within a conformationally flexible <i>exo</i>-chelated six-membered palladacycle. An array of valuable chiral diarylmethanols were obtained in high yield, good enantioselectivity, and broad functional group tolerance. Gram-scale synthesis was readily carried out and a diverse range of transformations were implemented with high retention of configuration, highlighting the synthetic utility of this method. Preliminary mechanistic studies indicated that CSAAs adopted an <i>N,O</i>-chelation mode, and the chiral induction proceeded through direct interaction between the <i>N</i>-<i>tert</i>-butanesulfinamide motif with the substrate.