Abstract

One-pot multicomponent reactions are an attractive synthetic strategy to generate multiple molecular scaffolds. Activation of a terminal alkyne C–H bond by transition metal catalysts is a reaction of fundamental interest in organic synthesis. One of the best examples of such a process is three components coupling of aldehydes, alkynes, and amines (A³-coupling). Herein, Cu(II)-containing nano-silica triazine based dendrimer was prepared, characterized and utilized as a retrievable catalytic system (Cu(II)-TrDen@nSiO₂) for green formation of propargylamines under solvent-free conditions. The various aldehydes/ketones, amines, and phenylacetylene were reacted at 100 °C in the presence of the 1.34 mol% of the catalyst to synthesize propargylamines in high yields (87%–98%). The prepared catalyst can be isolated assisted by a simple filtration and recovered for five courses without significant reduction in its efficiency. The as-prepared nano-catalyst was characterized by FT-IR, TEM, SEM, EDX, TGA and ICP. Performing the reactions in environmentally friendly and affordable conditions, the low catalyst percentage, high yield of products, short reaction times and easy workup are the merits of this protocol.

摘要

一锅多组分反应是一种有吸引力的合成策略，可生成多种分子支架。过渡金属催化剂活化末端炔烃 C-H 键是有机合成中最重要的反应。这种方法的最佳例子之一是醛、炔烃和胺的三组分偶联（A ³ -偶联）。在此，制备、表征了含 Cu(II) 的纳米二氧化硅三嗪基树枝状大分子并将其用作可回收的催化体系 (Cu(II)-TrDen@nSiO ₂) 用于在无溶剂条件下绿色生成炔丙基胺。在 1.34 mol% 的催化剂存在下，各种醛/酮、胺和苯乙炔在 100 °C 下反应，以高收率 (87%–98%) 合成炔丙基胺。制备的催化剂可以通过简单的过滤进行分离，并在五个过程中回收，而不会显着降低其效率。所制备的纳米催化剂通过FT-IR、TEM、SEM、EDX、TGA和ICP进行了表征。在环境友好和负担得起的条件下进行反应, 催化剂百分比低, 产品收率高, 反应时间短, 易于处理是该协议的优点。