Silylative Kinetic Resolution of Acyclic Secondary Benzylic Alcohols Catalyzed by Chiral Guanidine Having Axial Chirality Containing a Methoxy Group

Comprehensive Summary New chiral guanidine catalysts having axial chirality containing a methoxy group were synthesized. Subsequently, their catalytic ability was examined by applying the silylative kinetic resolution of racemic alcohols using chlorosilanes. Based on an X‐ray crystallographic analysis of the catalysts, the functional role of the methoxy group was predicted, and the plausible reaction pathways and a transition state were described. It was also revealed that the existence of hydrogen bonding between the methoxy group on the catalyst and hydrogen atom at C‐1 position of the substrates was of great importance for attaining high selectivity and reactivity. The proposed method is applicable to various acyclic aryl, heteroaryl, and normal‐alkyl alcohols exhibiting medium to high s ‐values ( s = 15–96, 15 examples).