作者:Christopher J. Moody、Elizabeth Swann、Christopher J. Moody、Leigh Ferris、David Haigh
DOI:10.1039/a706658i
日期:——
A new approach to the synthesis of dipeptides is described based on the formation of the NHCHR1CONH–CHR2CO bond by carbenoid N–H insertion, rather than the formation of the peptide bond itself.
triethyl diazophosphonoacetate catalysed by rhodium(II) acetate in the presence of N-protected amino acid amides 8 gives the phosphonates 9. Subsequent Wadsworth-Emmons reaction of 9 with aldehydes in the presence of DBU gives dehydro dipeptides 10. The reaction has been extended to a simple two-step procedure, without the isolation of the intermediate phosphonate, for conversion of a range of amino acid
The rearrangement of (E)-didehydroamino acid derivatives to the corresponding Z-derivatives under acid or basic catalysis as well as under the influence of radicals has been investigated. The condensation of N-benzyloxycarbonyl or N-tert-butoxycarbonyl protected alkyl 2-amino-2-(dimethoxyphosphoryl)acetates with aldehydes or ketones in dichloromethane in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene furnishes (Z)-didehydroamino acid ester derivatives diastereoselectively in excellent yields and with high purity.
研究了在酸或碱催化以及自由基影响下,(E)-二脱氢氨基酸衍生物重排为相应的 Z 衍生物的过程。在 1,8- 二氮杂双环[5.4.0]十一碳-7-烯存在下,N-苄氧羰基或 N-叔丁氧羰基保护的 2-氨基-2-(二甲氧基磷酰)乙酸烷基酯与醛或酮在二氯甲烷中缩合,可产生非对映选择性的 (Z)-二脱氢氨基酸酯衍生物,收率极高,纯度也很高。
Amino Acids and Peptides; XLIII<sup>1</sup>. Dehydroamino Acids; XVIII<sup>2</sup>. Synthesis of Dehydroamino Acids and Amino Acids from<i>N</i>-Acyl-2-(dialkyloxyphosphinyl)-glycin Esters; II