Catalytic Asymmetric Synthesis of Isoxazolines from Silyl Nitronates
摘要:
1,3-Dipolar Cycloadditions of triisopropylsilyl intronates and 2-alkylacroleins produced isoxazolines bearing a chiral quaternary center in high yields-and enantioselectivities with the aid of a chiral oxazaborolidine catalyst. One chiral isoxazoline product was converted to (R)-(+)-Tanikolide in 9 steps in a total yield of 43%.
Unanticipated Silyl Transfer in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis Using Silyl Nitronates
作者:Anastassia Matviitsuk、Mark D. Greenhalgh、James E. Taylor、Xuan B. Nguyen、David B. Cordes、Alexandra M. Z. Slawin、David W. Lupton、Andrew D. Smith
DOI:10.1021/acs.orglett.9b04404
日期:2020.1.3
The use of silyl nitronates is reported for the isothiourea-catalyzed synthesis of γ-nitro-substituted silyl esters containing up to two contiguous stereocenters in good yields with excellent enantioselectivities (up to 93% yield and 99:1 er). The serendipitously discovered formation of silyl ester products in this reaction demonstrates a novel platform for catalyst turnover in α,β-unsaturated acyl
Catalytic Asymmetric Synthesis of Isoxazolines from Silyl Nitronates
作者:Xiaoyu Han、Li Dong、Caiwei Geng、Peng Jiao
DOI:10.1021/acs.orglett.5b00826
日期:2015.7.2
1,3-Dipolar Cycloadditions of triisopropylsilyl intronates and 2-alkylacroleins produced isoxazolines bearing a chiral quaternary center in high yields-and enantioselectivities with the aid of a chiral oxazaborolidine catalyst. One chiral isoxazoline product was converted to (R)-(+)-Tanikolide in 9 steps in a total yield of 43%.