<i>N</i>H-1,2,3-Triazoles from Azidomethyl Pivalate and Carbamates: Base-Labile N<i>-</i>Protecting Groups
作者:K. Barry Sharpless、Jon C. Loren、Antoni Krasiński、Valery V. Fokin
DOI:10.1055/s-2005-918944
日期:——
NH-1,2,3-triazoles have been prepared via the copper(I)-catalyzed 1,3-dipolar cycloaddition between terminal alkynes and three N-protected organic azides, azidomethyl pivalate, azidomethyl morpholine-4-carboxylate, and azidomethyl N,N-diethylcarbamate. These organic azides were easily prepared on 0.1-mol scale in one or two steps from inexpensive commercially available materials. The cleaving properties of N-substituents in the resulting 1,2,3-triazole products with aqueous sodium hydroxide vary from <10 minutes at room temperature in the case of N-methyl pivalate, to 24 hours at room temperature in the case of N-methyl morpholine-4-carboxylate, to 24 hours at 85 °C in the case of N-methyl diethylcarbamate.
通过铜(I)催化的1,3-偶极环加成反应,NH-1,2,3-三氮唑已由末端炔烃与三种N-保护的有机叠氮化合物制备得到,这些有机叠氮化合物分别是叠氮甲基叔丁酯、叠氮甲基吗啉-4-羧酸酯和叠氮甲基N,N-二乙基氨基甲酸酯。这些有机叠氮化合物在0.1摩尔规模上通过一步或两步简单地从市售廉价原料制备。所得1,2,3-三氮唑产物中N-取代基的水解特性随氢氧化钠水溶液的条件不同而变化,其中N-甲基叔丁酯在室温下小于10分钟即可水解,N-甲基吗啉-4-羧酸酯在室温下需24小时,而N-甲基二乙基氨基甲酸酯在85°C下需24小时。