Cycloadditions between methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate and various tosylacetamides: Synthesis of trifluoromethylated pyroglutamates and 2-pyridones derivatives
作者:Hong-Hai Zhang、Wei Shen、Long Lu
DOI:10.1016/j.tetlet.2018.01.095
日期:2018.3
Cycloaddition reactions between methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate and various 2-tosylacetamides are described. Various 2-tosylacetamides react with methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate in the presence of NaH at room temperature in one step to form trifluoromethylated pyroglutamates as single diastereomers. However, employing the same reactants using t-BuOK as base at −78 °C results
描述了(Z)-2-溴-4,4,4-三氟-2-丁烯酸甲酯与各种2-甲苯磺酰基乙酰胺之间的环加成反应。在室温下,在NaH存在下,各种2-甲苯基乙酰胺与(Z)-2-溴-4,4,4-三氟-2-丁烯酸甲酯在室温下反应,以形成单一非对映异构体的三氟甲基化焦谷氨酸酯。然而,在-78℃下使用以t- BuOK为碱的相同反应物导致三氟甲基化2-吡啶酮的形成。提出了反应的闭环机理。