硼酸催化三组分无溶剂“一锅法””合成5-[(3-吲哚基)-甲基]-2,2-亚丁基-1,3-二噁烷-4,6-二酮衍生物

Solvent-Free One-Pot Three-Component Synthesis of 5-[(Indol-3-yl)-methyl]-2,2-butylidene-1,3-dioxane-4,6-dione Derivatives with B(OH)_3 as Catalyst

在硼酸催化下,以吲哚、醛和2,2-亚丁基-1,3-二噁烷-4,6-二酮为原料,经三组分无溶剂条件合成了9种5-[（3-吲哚基）-甲基]-2,2-亚丁基-1,3-二噁烷-4,6-二酮衍生物.当催化剂的用量为5 mol%时,60℃反应30~90 min,收率为68.6%~91.3%.此外,还探讨了硼酸可能的催化机理.该方法具有反应条件温和,反应时间短且收率高的优点.硼酸催化剂对环境友好且可循环利用.

Nine kinds of 5-[（indol-3-yl）-methyl]-2,2-butylidene-l,3-dioxane-4,6-dione derivatives were synthesized by the three-component one-pot reaction of indole with aldehydes and 2,2-butylidene-1,3-dioxane-4,6-dione in the presence of boric acid under solvent-free. The results indicated that the yields ranged from 68.6% to 91.3%, when using 5 mol% boric acid and reacting at 60 ℃for 30~90 min. Furthermore, a proposed reaction mechanism for the reaction catalyzed by boric acidwas speculated. The main advantages of the present procedure were milder conditions, shorter reaction time and higher yields. Further study showed that boric acid was environmentally friendly and reused for six times without any noticeable decrease in the catalytic activity.