A Catalyst-Controlled Enantiodivergent Bromolactonization

A catalyst-controlled enantiodivergent bromolactonization of olefinic acids has been developed. Quinine-derived amino-amides bearing the same chiral core but different achiral aryl substituents were used as the catalysts. Switching the methoxy substituent in the aryl amide system from meta- to ortho-position results in a complete switch in asymmetric induction to afford the desired lactone in good enantioselectivity and yield. Mechanistic studies, including chemical experiments and density functional theory calculations, reveal that the differences in steric and electronic effects of the catalyst substituent alter the reaction mechanism.

Automated summary

A catalyst-controlled enantiodivergent bromolactonization of olefinic acids has been developed by using different quinine-derived amino-amides as catalysts. Switching the position of the methoxy substituent in the aryl amide system alters the asymmetric induction, leading to the desired lactone with good enantioselectivity and yield. Mechanistic studies reveal that the differences in steric and electronic effects of the catalyst substituent affect the reaction mechanism.