426827-26-1Relevant articles and documents
Discovery and Biocatalytic Application of a PLP-Dependent Amino Acid ?-Substitution Enzyme That Catalyzes C-C Bond Formation
Chen, Mengbin,Liu, Chun-Ting,Tang, Yi
supporting information, p. 10506 - 10515 (2020/09/21)
Pyridoxal phosphate (PLP)-dependent enzymes can catalyze transformations of l-amino acids at α, β, and γpositions. These enzymes are frequently involved in the biosynthesis of nonproteinogenic amino acids as building blocks of natural products and are attractive biocatalysts. Here, we report the discovery of a two-step enzymatic synthesis of (2S,6S)-6-methyl pipecolate 1, from the biosynthetic pathway of citrinadin. The key enzyme CndF is PLP-dependent and catalyzes the synthesis of (S)-2-amino-6-oxoheptanoate 3 that is in equilibrium with the cyclic Schiff base. The second enzyme CndE is a stereoselective imine reductase that gives 1. Biochemical characterization of CndF showed this enzyme performs ?-elimination of O-acetyl-l-homoserine to generate the vinylglycine ketimine, which is subjected to nucleophilic attack by acetoacetate to form the new C?-C? bond in 3 and complete the ?-substitution reaction. CndF displays promiscuity toward different β-keto carboxylate and esters. With use of an Aspergillus strain expressing CndF and CndE, feeding various alkyl-β-keto esters led to the biosynthesis of 6-substituted l-pipecolates. The discovery of CndF expands the repertoire of reactions that can be catalyzed by PLP-dependent enzymes.
The intriguing reactivity of functionalized β-amino alcohols with glyoxal: Application to a new expedient enantioselective synthesis of trans-6-alkylpipecolic acids
Agami, Claude,Comesse, Sebastien,Kadouri-Puchot, Catherine
, p. 2424 - 2428 (2007/10/03)
New β-amino alcohols possessing a vinylsilane moiety were reacted with glyoxal to produce lactones that were transformed in three steps in enantiopure pipecolic acid derivatives. The key step was a totally diastereoselective ene-iminium cyclization, whose mechanism can be viewed as a direct cyclization of the vinylsilane moiety onto the iminium ion. The reactivity of two β-amino alcohols having an allylsilane terminator was also examined. Their difference of reactivity toward glyoxal can be ascribed to the intervention of a carbocation, which presents a behavior that differs according to the position of the trimethylsilyl group.
Asymmetric Synthesis. 32. A New Access to Enantiomerically Pure (S)-(-)-Pipecolic Acid and 2- or 6-Alkylated Derivatives
Berrien, J. -F.,Royer, J.,Husson, H. -P.
, p. 3769 - 3774 (2007/10/02)
Enantiomerically pure (S)-(-)-pipecolic acid (5) was synthesized in four steps and 47percent overall yield starting from 2-cyano-6-phenyloxazolopiperidine (1).A general strategy is described for preparing 2-alkylated and 6-alkylated pipecolic acid 7a-c and 11a-c using diastereoselective procedures.
