Asymmetric Synthesis of 2-Alkyl-3-phosphonopropanoic Acids via P−C Bond Formation and Hydrogenation
摘要:
Allylic acetates, formed by the acetylation of Baylis Hillman adducts, undergo addition of phosphorus nucleophiles to give stereoselectively the Z-unsaturated esters. TFA cleavage of the tert-butyl ester and asymmetric hydrogenation of the unsaturated acid yields the phosphono alkyl propanoic acid moiety, commonly found in phosphonate- and phosphinate-based enzyme inhibitors.
Asymmetric Synthesis of 2-Alkyl-3-phosphonopropanoic Acids via P−C Bond Formation and Hydrogenation
摘要:
Allylic acetates, formed by the acetylation of Baylis Hillman adducts, undergo addition of phosphorus nucleophiles to give stereoselectively the Z-unsaturated esters. TFA cleavage of the tert-butyl ester and asymmetric hydrogenation of the unsaturated acid yields the phosphono alkyl propanoic acid moiety, commonly found in phosphonate- and phosphinate-based enzyme inhibitors.
The organocatalyzed regioselective allylic trifluoromethylation of Morita–Baylis–Hillman adducts using Ruppert–Prakash reagent was achieved in high to excellent yields via a successive SN2′/SN2′ mode for the first time. The reaction was extended to the asymmetric allylic trifluoromethylation by the use of a bis-cinchona alkaloid catalyst with high enantioselectivities up to 94% ee.
首次通过连续的S N 2'/ S N 2'模式,使用Ruppert-Prakash试剂对Morita-Baylis-Hillman加合物进行了有机催化的区域选择性烯丙基三氟甲基化反应,收率很高。通过使用具有高达94%ee的高对映选择性的双金鸡纳生物碱催化剂,反应扩展到不对称的烯丙基三氟甲基化反应。