Asymmetric Synthesis of Diarylmethyl Sulfones by Palladium‐Catalyzed Enantioselective Benzylic Substitution: A Remarkable Effect of Water

Abstract

A Pd/(R)-BINAP-catalyzed enantioselective benzylic sulfonation of diarylmethyl carbonates with sodium sulfinates proceeds to deliver the corresponding chiral diarylmethyl sulfones in good yields with high enantioselectivity. The reaction occurs in a dynamic kinetic asymmetric transformation (DYKAT) manner and thus provides convergent access to optically active benzylic sulfones from racemic secondary benzylic carbonates. Additionally, the addition of H O is found to be critical for high enantioselectivity.

Synthesis and applications of sodium sulfinates (RSO2Na): a powerful building block for the synthesis of organosulfur compounds

“…The reaction proceeded in a dynamic kinetic asymmetric transformation (DYKAT) manner to form the enantiomerically enriched benzylic sulfones ( Scheme 260 ). 368 As the authors observed, the addition of H 2 O was found to be critical for high enantioselectivity. Several secondary benzylic carbonates with sodium benzenesulfinate delivered the corresponding chiral diarylmethyl sulfones in good yields with high enantioselectivity.…”

Water-enabling strategies for asymmetric catalysis

“…In 2018, Miura et al described an asymmetric benzylic substitution of diarylmethyl carbonates with sodium sulfinates (Scheme 19). 37 The enantioselectivity was very low or almost absent under anhydrous conditions or with other proton sources. Only water had a positive impact on enantioselectivity, and up to 98% ee could be obtained under optimized conditions.…”

Palladium-Catalyzed Benzylic Phosphorylation of Diarylmethyl Carbonates

“…On the other hand, our research group recently developed the palladium-catalyzed benzylic substitution of readily accessible and easy-to-handle diarylmethyl carbonates with carbon, nitrogen, oxygen, and sulfur nucleophiles . Additionally, the asymmetric version was also realized by the judicious choice of chiral bisphosphine ligands.…”