Asymmetric conjugate reductions with samarium diiodide: asymmetric synthesis of (2S,3R)- and (2S,3S)-[2-2H,3-2H]-leucine-(S)-phenylalanine dipeptides and (2S,3R)-[2-2H,3-2H]-phenylalanine methyl ester,10.1039/B500566C

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Lactoyl-CoA 全氟丁基戊烷白叶藤碱全氟己基辛烷新白叶藤碱壳寡糖特色专题-生物多肽

Asymmetric conjugate reductions with samarium diiodide: asymmetric synthesis of (2S,3R)- and (2S,3S)-[2-2H,3-2H]-leucine-(S)-phenylalanine dipeptides and (2S,3R)-[2-2H,3-2H]-phenylalanine methyl ester

Stephen G. Davies,Humberto Rodríguez-Solla,Juan A. Tamayo,Andrew R. Cowley,Carmen Concellón,A. Christopher Garner,Alastair L. Parkes,Andrew D. Smith

Organic & Biomolecular Chemistry Pub Date : 03/17/2005 00:00:00 , DOI:10.1039/B500566C

Abstract

The highly diastereoselective samarium diiodide and D₂O-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 ≥95% de and >98% ee, and (2S,3R)- or (2S,3S)-dideuterioleucine-(S)-phenylalanine dipeptides 37 and 38 in moderate de, 66% and 74% respectively. A mechanism is proposed to account for this process.