Asymmetric conjugate reductions with samarium diiodide: asymmetric synthesis of (2S,3R)- and (2S,3S)-[2-<sup>2</sup>H,3-<sup>2</sup>H]-leucine-(S)-phenylalanine dipeptides and (2S,3R)-[2-<sup>2</sup>H,3-<sup>2</sup>H]-phenylalanine methyl ester
作者:Stephen G. Davies、Humberto Rodríguez-Solla、Juan A. Tamayo、Andrew R. Cowley、Carmen Concellón、A. Christopher Garner、Alastair L. Parkes、Andrew D. Smith
DOI:10.1039/b500566c
日期:——
diastereoselective samarium diiodide and D(2)O-promoted conjugate reduction of homochiral (E)- and (Z)-benzylidene and isobutylidene diketopiperazines (E)-5,7 and (Z)-6,8 has been demonstrated. This methodology allows the asymmetric synthesis of methyl (2S,3R)-dideuteriophenylalanine 27 in > or = 95% de and >98% ee, and (2S,3R)- or (2S,3S)-dideuterioleucine-(S)-phenylalanine dipeptides 37 and 38 in moderate de,
已经证明了高度非对映选择性的二碘化and和D(2)O促进的同手性(E)-和(Z)-亚苄基和异丁烯二酮哌嗪(E)-5,7和(Z)-6,8的共轭还原。这种方法学允许不对称合成95%de和98%ee或以下的(2S,3R)-或(2S,3S)-二氘代亮氨酸-(S)-苯丙氨酸的甲基(2S,3R)-二氘代苯丙氨酸二肽37和38分别处于中等水平,分别为66%和74%。提出了一种机制来说明此过程。