DFT Studies on Pd/Xiao‐Phos‐Catalyzed Asymmetric Arylation of Secondary Phosphine Oxides.

Asymmetric arylation of secondary phosphine oxides (SPOs) has been rapidly developed, while there are few theoretical studies reported. DFT computations were carried out to study the whole catalytic cycle of Pd/Xiao‐Phos‐catalyzed asymmetric arylation of SPOs, and a modified mechanism including tautomerization and arylation was presented. Some new tautomerization mechanisms have been traversed, including base‐assisted and Pd/Xiao‐Phos‐catalyzed tautomerization. These are different from the existing report, where base‐assisted tautomerization is the most favored. The resulting intermediate enters the downstream arylation directly. Furthermore, oxidative addition is identified as the enantioselectivity‐determining step. IGMH analysis results indicate that the different non‐bonding interactions between Xiao‐Phos and SPO parts determine the enantioselectivity. This work not only provides deeper insights into the self‐adaptive property of SadPhos ligands but also offers valuable guidance for ligand design. Newly proposed tautomerization mechanisms will also bring some inspiration to subsequent related research. [ABSTRACT FROM AUTHOR]