The reaction of chlorosulfonyl isocyanates with allenes and olefins
作者:Emil J. Moriconi、John F. Kelly
DOI:10.1021/jo01272a005
日期:1968.8
Au-Catalyzed Synthesis of 5,6-Dihydro-8<i>H</i>-indolizin-7-ones from <i>N</i>-(Pent-2-en-4-ynyl)-β-lactams
作者:Yu Peng、Meng Yu、Liming Zhang
DOI:10.1021/ol802159v
日期:2008.11.20
Au-catalyzed synthesis of 5,6-dihydro-8H-indolizin-7-ones from readily available N-(pent-2-en-4-ynyl)-beta-lactams is developed. In this reaction, a 5-exo-dig cyclization of the beta-lactam nitrogen to the Au-activated C-C triple bond is followed by heterolytic fragmentation of the amide bond, forming a highly nucleophilic acyl cation. An expedient formal synthesis of indolizidine 167B was easily achieved using this new method.
Synthesis and conformational analysis of an
<i>anti</i>
‐β
<sup>2,</sup>
<scp>
<sup>3</sup>
‐amino
</scp>
acid as a building block for unnatural peptide helices
作者:Sunglim Choi、Soo Hyuk Choi
DOI:10.1002/bkcs.12457
日期:2022.2
Anti-β2,3-amino acids are a class of acyclic β-amino acids that usually stabilize β-sheet-like conformations of unnatural peptides. (2S,3R)-3-amino-2-ethylpentanoic acid (AEPA) is a diethyl-substituted anti-β2,3-amino acid that can be regarded as an acyclic analog of cis-2-aminocyclohexanecarboxylic acid, which is known to promote the α/β-peptide 11/9-helix and the β-peptide 12/10-helix. We report
抗-β 2,3-氨基酸是一类通常稳定非天然肽的β-折叠样构象的无环β-氨基酸。(2 S ,3 R )-3-amino-2-ethylpentanoic acid (AEPA) 是一种二乙基取代的反-β 2,3 - 氨基酸,可视为顺式-2-氨基环己烷羧酸的无环类似物,已知可促进 α/β-肽 11/9-螺旋和 β-肽 12/10-螺旋。我们报告说,AEPA 可以掺入两个非天然肽螺旋中,而不会破坏螺旋折叠。晶体结构数据显示,抗-β 2,3 -残基采用非常规的gauche(+) 那些非天然肽螺旋中的构象。