1254701-76-2Relevant academic research and scientific papers
A Catalyst-Controlled Enantiodivergent Bromolactonization
Chan, Yuk-Cheung,Lam, Ying-Pong,Tse, Ying-Lung Steve,Wang, Xinyan,Wong, Jonathan,Yeung, Ying-Yeung
supporting information, p. 12745 - 12754 (2021/08/30)
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.
Asymmetric bromolactonization using amino-thiocarbamate catalyst
Zhou, Ling,Tan, Chong Kiat,Jiang, Xiaojian,Chen, Feng,Yeung, Ying-Yeung
supporting information; scheme or table, p. 15474 - 15476 (2011/02/21)
A novel amino-thiocarbamate-catalyzed bromolactonization of unsaturated carboxylic acids has been developed. The scope of the reaction is evidenced by 22 examples of γ-lactones with up to 99% yield and 93% ee. The protocol was applied in the enantioselective synthesis of the key intermediates of VLA-4 antagonists.
