Transition metal-free one-pot cascade synthesis of 7-oxa-2-azatricyclo[7.4.0.02,6]trideca-1(9),10,12-trien-3-ones from biomass-derived levulinic acid under mild conditions
作者:Amitabh Jha、Ajaya B. Naidu、Ashraf M. Abdelkhalik
DOI:10.1039/c3ob41826j
日期:——
An efficient, environmentally benign, transition-metal free, tandem C–N, C–O bond formation reaction is developed for the synthesis of tricyclic 7-oxa-2-azatricyclo[7.4.0.02,6]trideca-1(9),10,12-trien-3-ones and their homologs from easily available starting materials, including renewable levulinic acid, a keto acid. The reaction of keto acids with methyl chloroformate and variously substituted o-aminobenzyl alcohols using triethylamine as a base in toluene at room temperature gave good to excellent yields. This newly developed protocol was successfully utilized for the synthesis of a variety of polycyclic 7-oxa-2-azatricyclo[7.4.0.02,6]trideca-1(9),10,12-trien-3-ones and related compounds.
开发了一种高效、环境友好、无需过渡金属的串联C-N、C-O键形成反应,用于从易于获得的起始原料,包括可再生的乙酰乙酸,一种酮酸,合成三环7-氧杂-2-氮杂三环[7.4.0.0²,6]十三碳-1(9),10,12-三烯-3-酮及其同系物。酮酸与氯甲酸甲酯和各种取代的邻氨基苄醇在甲苯中室温下使用三乙胺作为碱进行反应,产率良好至优秀。这一新开发的方案成功地应用于合成多种多环7-氧杂-2-氮杂三环[7.4.0.0²,6]十三碳-1(9),10,12-三烯-3-酮及相关化合物。