The chemistry of imidazolium-catalyzed imidazolium synthesis was studied as part of an effort to develop a plausible prebiotic synthesis of a small catalytic molecule capable of catalyzing its own synthesis. Specifically, we investigated the one-pot 1-ethyl-3-methylimidazolium acetate (EMIM-Ac) catalyzed synthesis of 1,3-dibutyl-4,5-difuryl-imidazolium acetate (DBDFIM-Ac) from furfural, n-butylamine, formaldehyde, and acetic acid at 80 °C. Liu et al. (2012) had previously demonstrated the first reaction of the synthetic process, the EMIM-Ac catalyzed benzoin condensation of furfural that yields furoin. Our early studies established the second reaction of the synthetic process, the multicomponent reaction of furoin, n-butylamine, formaldehyde, and acetic acid that yields the imidazolium salt, DBDFIM-Ac. Studies of the complete two-reaction process that uses furfural for the synthesis of DBDFIM-Ac showed that the highest yield of DBDFIM-Ac was obtained when the mole ratio of n-butylamine, formaldehyde, and acetic acid relative to furfural was respectively (0.5:0.25:0.25:1.0-furfural), or one-half of the stoichiometric ratio (1.0:0.5:0.5:1.0-furfural). A time course study of the process showed transient formation of furoin, the obligatory reaction intermediate. DBDFIM-Ac and the imidazolium side product, 1,3-dibutyl-4,5-trifuryl-imidazolium acetate (DBTFIM-Ac), were stable under the reaction conditions. Imidazolium products (DBDFIM and DBTFIM) and the furoin intermediate were not formed in control reactions (80 °C, 24 h) in which EMIM catalyst was either absent or replaced with an equal volume of acetonitrile or DMF. The imidazolium product, DBDFIM-Ac, was shown to catalyze the synthesis of structurally similar 1,3-dipentyl-4,5-difuryl-imidazolium acetate (DPDFIM-Ac) from furfural, n-pentylamine, formaldehyde, and acetic acid at 80 °C.

中文翻译：

---

咪唑鎓催化剂的咪唑鎓催化合成。


对咪唑鎓催化的咪唑鎓合成的化学进行了研究，作为开发一种能够催化其自身合成的小催化分子的合理的益生元合成的努力的一部分。具体来说，我们研究了以糠醛、正丁胺、甲醛和乙酸，80°C。刘等人。 (2012) 之前已经演示了合成过程的第一个反应，即 EMIM-Ac 催化糠醛的安息香缩合，生成糠醛。我们的早期研究建立了合成过程的第二个反应，即糠秕、正丁胺、甲醛和乙酸的多组分反应，生成咪唑鎓盐 DBDFIM-Ac。对糠醛合成 DBDFIM-Ac 的完整双反应过程的研究表明，当正丁胺、甲醛和乙酸相对于糠醛的摩尔比分别为（0.5）时，获得最高的 DBDFIM-Ac 产率。 :0.25:0.25:1.0-糠醛），或化学计量比的二分之一（1.0:0.5:0.5:1.0-糠醛）。该过程的时间进程研究表明，短暂形成了必须的反应中间体——弗洛因。 DBDFIM-Ac 和咪唑鎓副产物 1,3-二丁基-4,5-三呋喃基-咪唑鎓乙酸盐 (DBTFIM-Ac) 在反应条件下稳定。在对照反应（80℃，24小时）中没有形成咪唑鎓产品（DBDFIM和DBTFIM）和呋喃中间体，其中EMIM催化剂要么不存在，要么用等体积的乙腈或DMF代替。 咪唑鎓产品 DBDFIM-Ac 在 80 ℃下催化由糠醛、正戊胺、甲醛和乙酸合成结构相似的 1,3-二戊基-4,5-二呋喃基-咪唑鎓乙酸盐 (DPDFIM-Ac)。 °C。