In situ generation and protonation of the isocyanide/acetylene adduct: a powerful catalyst-free strategy for multicomponent synthesis of ketenimines, aza-dienes, and heterocycles

Abstract

In addition to isocyanide-based Ugi, Passerini, van Leusen, and Orru multicomponent reactions, a new class of isocyanide/acetylene-based multicomponent reactions, using zwitterionic adducts, have emerged as powerful methods to synthesize biologically interesting molecules.

Isocyanide-based multicomponent reactions in the synthesis of heterocycles

“…The organic segment is connected to the isocyanide group via the nitrogen atom, not via the carbon. They are used as privileged synthons for the synthesis of other organic compounds in particular various heterocycles [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] , frequently via multicomponent reactions (MCRs) namely isocyanide multicomponent reactions (IMCRs) 25,[38][39][40][41][42][43][44][45][46][47][48][49] . Noticeably isocyanides are susceptible to polymerization 50 .…”

Synergy Effects in the Chemical Synthesis and Extensions of Multicomponent Reactions (MCRs)—The Low Energy Way to Ultra-Short Syntheses of Tailor-Made Molecules

“…IMCRs [ 38 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], alkyne-based [ 38 , 51 , 52 , 53 , 54 ] and C-H-acidic compound [ 55 , 56 , 57 , 58 , 59 , 60 ]-based MCRs in particular have a high potential to be very diverse. Many novel MCRs [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ] have meanwhile become part of the range of syntheses, e.g., boron-mediated [ 62 , 66 ], photo-induced [ 67 ] and carbene-based MCRs [ 72 ] such as N-heterocyclic carbenes (NHCs).…”

Synthesis of Quinazoline Derivatives Catalyzed by a New Efficient Reusable Nanomagnetic Catalyst Supported with Functionalized Piperidinium Benzene‐1,3‐Disulfonate Ionic Liquid

“…In these protocols, the whole range of compounds could be synthesized by minimizing waste, time and cost without intermediates isolation . In recent years, many publications based on MCRs have been reported which emphasizes their highlighted applications in organic and medicinal chemistry . In MCRs catalyst plays an important role by altering the required activation energy.…”