Zum Mechanismus der ?-Alkinon-Cyclisierung: Synthese und Thermolyse von 1-(1-Methylcyclopentyl)[3-13C]prop-2-inon
作者:Manuel Koller、Martin Karpf、Andr� S. Dreiding
DOI:10.1002/hlca.19830660844
日期:1983.12.14
On the Mechanism of the α-Alkynone Cyclization: Synthesis and Thermolysis of 1-(1-Methylcyclopentyl)[3-13C]prop-2-ynone
关于α-炔酮环化的机理:1-(1-甲基环戊基)[3- 13 C]丙-2-炔酮的合成和热解
Construction of thioglycoside bonds via an asymmetric organocatalyzed sulfa-Michael/aldol reaction: access to 4′-thionucleosides
作者:Tao Wei、Ming-Sheng Xie、Hai-Ming Guo
DOI:10.1039/d4cc00984c
日期:——
Thioglycoside bond formation via an asymmetric sulfa-Michael/aldol reaction of (E)-β-nucleobase acrylketones and 1,4-dithiane-2,5-diol has been achieved with a cinchona alkaloid-derived bifunctional squaramide chiral catalyst. Diverse purine, benzimidazole, and imidazole substrates are well tolerated and generate 4′-thionucleoside derivatives containing three contiguous stereogenic centers with excellent results
使用金鸡纳生物碱衍生的双功能方酰胺手性催化剂,通过( E )-β-核碱基丙烯酮和 1,4-二噻烷-2,5-二醇的不对称磺基-迈克尔/羟醛反应形成硫代糖苷键。多种嘌呤、苯并咪唑和咪唑底物具有良好的耐受性,并生成含有三个连续立体中心的 4'-硫代核苷衍生物,具有优异的结果(30 个示例,高达 97% 的产率,>20 : 1 dr 和高达 99% ee)。此外,该新策略为构建手性4'-硫代核苷提供了一种高效、便捷的合成路线。