The BF<sub>3</sub>×OEt<sub>2</sub>-Assisted Conversion of Nitriles into Thioamides with Lawesson’s Reagent
作者:Walther Schmid、Michael Nagl、Claudia Panuschka、Andrea Barta
DOI:10.1055/s-0028-1083253
日期:2008.12
A method for the thiolysis of nitriles by applying Lawesson’s reagent and facilitated by the addition of boron trifluoride-diethyl ether complex is reported. The method opens an easy access to primary thioamides. Aromatic, benzylic, and aliphatic nitriles were converted into the corresponding thioamides in high to quantitative yields (even in unfavorable cases, e.g., ortho-substituted benzonitriles). The reaction was performed in 1,2-dimethoxyethane-tetrahydrofuran or toluene-diethyl ether solvent mixtures at 20-50 ËC, and exhibited considerable selectivity in the case of multifunctional nitrile substrates, such as cyanomethyl N-acetylphenylalaninate, benzoylacetonitrile, 4-cyanobenzamide, 4-acetyl-benzonitrile, or pent-3-enenitrile.
报道了一种利用Lawesson试剂进行腈的硫解反应的方法,并通过添加三氟化硼二乙醚复合物来促进反应。该方法为制备一级硫酰胺提供了简便途径。芳香族、苄基和脂肪族腈在高至定量的产率下被转化为相应的硫酰胺(即使在不利情况下,例如邻位取代的苄腈)。反应在1,2-二甲氧基乙烷-四氢呋喃或甲苯-二乙醚溶剂混合物中于20-50℃进行,并对多功能腈底物表现出显著的选择性,如氰甲基N-乙酰苯丙氨酸酯、苯甲酰丙二腈、4-氰基苯甲酰胺、4-乙酰基苯甲腈或戊-3-烯腈。