Friedländer condensation between 2-aminoaryl ketones and different carbonyl compounds, catalyzed by CuBTC was investigated by a combination of various experimental techniques and by density functional theory based modelling. CuBTC exhibiting hard Lewis acid character showed highly improved catalytic activity when compared with other molecular sieves showing high concentraion of Lewis acid sites, e.g. in BEA and (Al)SBA-15. Polysubstituted quinolines were synthesized via a Friedländer reaction catalyzed by CuBTC under the solvent-free conditions. High concentration of active sites in CuBTC together with the concerted effect of a pair of adjacent Cu2+ coordinatively unsaturated active sites are behind a very high quinoline yield reached within a short reaction time. Results reported here make CuBTC a promising catalyst for other Lewis acid-promoted condensations, including those leading to biologically active compounds with a particular relevance for the pharmaceutical industry. The mechanism of a catalyzed Friedländer reaction investigated computationally is also reported.
对Friedländer缩聚反应在2-
氨基芳基酮和不同羰基化合物之间,采用Cu
BTC作为催化剂的研究,结合了多种实验技术和基于密度泛函理论的建模。具有硬
路易斯酸特性的Cu
BTC展现出了比其他
分子筛(如BEA和(Al)SBA-15,它们的
路易斯酸位点浓度高)更高的催化活性。在无溶剂条件下,通过Cu
BTC催化的Friedländer反应合成了多取代
喹啉。Cu
BTC中高浓度的活性位点以及相邻的一对配位不饱和的Cu2+活性位点的协同效应,是其在一小段时间内达到极高
喹啉产率的原因。这里报告的结果使Cu
BTC成为其他
路易斯酸促进缩聚反应的有力催化剂,包括那些导致
生物活性化合物产生的反应,对制药行业具有特别重要意义。同时,还报告了通过计算研究得出的催化Friedländer反应的机理。