Department of Chemistry, Gilman Hall, Iowa State University, Ames, Iowa 50011, United States.
J Org Chem. 2010 Nov 5;75(21):7166-74. doi: 10.1021/jo1012515.
The bicyclic triaminophosphine P(RNCH(2)CH(2))(3)N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated. We were able to isolate and characterize (by X-ray means; see above) the reactive WE intermediate species formed from 2b and 1c.
双环三胺膦 P(RNCH(2)CH(2))(3)N（R = i-Bu，1c）可用作有效促进剂，在室温下从各种芳族、脂肪族、杂环和环状醛和酮，使用一系列 Wadsworth-Emmons（WE）膦酸酯，立体选择性合成α，β-不饱和酯、氟化物和腈。在 1c 的类似物[R = Me（1a），i-Pr（1b），Bn（1d）]中，1a 和 1b 表现良好，尽管反应时间较长，而 1d 的产率低于 1c。氰基、氯、溴、甲氧基、氨基、酯和硝基等官能团得到了很好的容忍。我们能够分离并通过 X 射线手段对 2b 和 1c 形成的反应性 WE 中间体进行表征（见上文）。
