A Catalyst-Controlled Enantiodivergent Bromolactonization
作者:Yuk-Cheung Chan、Xinyan Wang、Ying-Pong Lam、Jonathan Wong、Ying-Lung Steve Tse、Ying-Yeung Yeung
DOI:10.1021/jacs.1c05680
日期:2021.8.18
enantiodivergent bromolactonization of olefinicacids 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
Enantioselective Functionalization of Radical Intermediates in Redox Catalysis: Copper-Catalyzed Asymmetric Oxytrifluoromethylation of Alkenes
作者:Rong Zhu、Stephen L. Buchwald
DOI:10.1002/anie.201307790
日期:2013.11.25
Something radical: An efficient enantioselectiveoxytrifluoromethylation of alkenes has been developed using a copper catalyst system. Mechanistic studies are consistent with a metal‐catalyzed redoxradical addition mechanism in which a CO bond is formed by the copper‐mediated enantioselective trapping of a prochiral alkyl radicalintermediate derived from the initial trifluoromethyl radical addition
Nitrene‐Mediated Enantioselective Intramolecular Olefin Oxyamination to Access Chiral γ‐Aminomethyl‐γ‐Lactones
作者:Xin Nie、Clayton W. Ritter、Marcel Hemming、Sergei I. Ivlev、Xiulan Xie、Shuming Chen、Eric Meggers
DOI:10.1002/anie.202314398
日期:2023.12.18
Nitrene-mediated asymmetric intramolecularolefin difunctionalization is introduced, in which the nitrene intermediate adds in an unprecedented exocyclic fashion and the nucleophile in an endocyclic fashion. This atom-economic strategy affords chiral γ-aminomethyl-γ-lactones in high yields and excellent enantioselectivities and provides access to versatile chiral building blocks.
A novel amino-thiocarbamate-catalyzed bromolactonization of unsaturated carboxylic acids has been developed. The scope of the reaction is evidenced by 22 examples of gamma-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.
Versatile Enantioselective Synthesis of Functionalized Lactones via Copper-Catalyzed Radical Oxyfunctionalization of Alkenes
作者:Rong Zhu、Stephen L. Buchwald
DOI:10.1021/jacs.5b04821
日期:2015.7.1
A versatile method for the rapid synthesis of diverse enantiomerically enriched lactones has been developed based on Cu-catalyzed enantioselective radical oxyfunctionalization of alkenes. The scope of this strategy encompasses a series of enantioselective difunctionalization reactions: oxyazidation, oxysulfonylation, oxyarylation, diacyloxylation, and oxyalkylation. These reactions provide straightforward access to a wide range of useful chiral lactone building blocks containing tetrasubstituted stereogenic centers, which are hard to access traditionally.