Environmentally Benign Neat Mechanochemical Synthesis and Photophysical Studies of Indolylquinolines via Silica gel Catalyzed Metal free A3‐Coupling

Abstract

An efficient neat mechanochemical method for the synthesis of fluorescent indolylquinonlines via A3-coupling reaction of 1phenylsulfonylindole-3-carbaldehyde (1), substituted anilines 2(a-j) and substituted phenylacetylene 3(a,b) using SiO 2 as an effective catalyst has been developed. The photophysical properties of newly synthesized indolylquinoline derivatives 4(a-l) were established and it depends on the nature of substituent at C6 position of quinoline moiety.[a] C.

A solvent-free mechanochemical synthesis of polyaromatic hydrocarbon derivatives

“…35,36 In order to gain a better understanding of this phenomenon, we added milling aids such as silica gel, which has been shown to provide signicant rate enhancements of mechanochemical processes. [37][38][39][40] Upon adding silica gel to the reaction mixture, we observed a signicant rate enhancement on the reactivity of the anthracene substrates. Currently, we are investigating the inuence of silica gel on these reactions in order to get a better understanding of this effect.…”

Metal-free multicomponent approach for the synthesis of propargylamine: a review

“…An exceptional product was reported by Yadav et al 38 among the A3 coupling of 1 aromatic amine 38, heteroaromatic aldehyde 39 and phenylacetylene 18a using silica gel (SiO 2 ) as catalyst under solvent-free condition. 61 This methodology provided an easy access of uorescent active indolylquinolines, 62 derivatives 40 (Scheme 19) instead of propargylamine.…”

“…27 There are only a few reports published in the literature describing the A3 and other MCR (multicomponent reaction) for the metal-free propargylamine synthesis. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] From the green and sustainable point of view, metal-free synthesis is the best eco-friendly approach while assessing environmental safety. The object of green chemistry mainly focuses on the development of novel methodologies and alternative sustainable synthetic strategies, which must include the environmental considerations.…”

A Novel Recyclable Ni/Cu/Fe Termetallic Nanocatalyst for the Synthesis of Propargylamines through the A3‐Coupling Reactions

“…This multimetallic nanocatalyst has very attractive potentials due to the synergistic effects of the multi metals . In addition, the coupling reactions using precious metals‐free and low cost metal systems are of great importance in organic synthesis …”