TMSCl-Catalyzed synthesis of substituted quinolines from arylimines and enolizable aldehydes

Abstract

Some substituted quinolines were effectively synthesized utilizing chlorotrimethylsilane (TMSCl) as efficient promoter in the cyclization addition of enolizable aldehydes to arylimines under an air atmosphere in DMSO. The clean, mild and ecofriendly process with high yields and a simple workup of the desired compounds are attractive features of the reaction which enables a facile preparation of the quinoline ring.

Synthesis of hexahydroquinolines using the new ionic liquid sulfonic acid functionalized pyridinium chloride as a catalyst

“…One series of DHP derivatives with an improved structural scaffold, the hexahydroquinoline derivatives (HHQs), can be synthesized according to a Hantzsch synthesis using aryl aldehydes, dimedone (5,5dimethylcyclohexane-1,3-dione), β-ketoesters, and ammonium acetate in a one-pot multi-component condensation reaction [31,32]. Quinolines bearing a 1,4-dihydropyridine scaffold have been identified as promising structure in medicinal chemistry because of their many pharmacological properties, including their antibacterial antihypertensive, anti-inflammatory, antimalarial, antiasthmatic, and tyrosine kinase inhibitory activity [33][34][35][36][37][38]. Furthermore, various methods and catalysts have been developed for the preparation of HHQs [39][40][41][42][43][44][45][46][47].…”

One-Pot Synthesis of 4,6-Diarylpyrimidin-2(1H)-Ones via Multicomponent Reaction Promoted by Chlorotrimethylsilane

“…TMSCl has also been reported as a mild, useful and inexpensive Lewis acid promoter for one-pot multicomponent reactions for the preparation of other heterocyclic compounds. 38,39 In previous work, [40][41][42][43] TMSCl was employed to carry out several unusual cyclo-condensations including one-pot synthesis of subtituted quinolines, oxazine-3-ones and pyrroles. Continuing our investigations on the TMSCl-promoted synthesis of heterocycles, we were interested to prepare 4,6diarylpyrimidin-2(1H)-ones from arylketones, substituted benzaldehydes and urea via the one-pot three-component reaction under air in DMF/CH 3 CN using TMSCl as promoting agent in the absence of other catalysts.…”

Different Reactivities of Alkoxy- and Thiocarbene Complexes of Fischer-Type: Formation of (N-Enamino)ethoxycarbene Complexes and Quinolines, Respectively

“…The conversion of vinylidenes into quinolines resembles the Povarov reaction, which involves [4+2] cycloaddition of N -aryl imines (Schiff bases) to nucleophilic olefins catalyzed by a Lewis acid, Bro̷nsted acid, or lanthanide triflate (Scheme ). The Povarov reaction is a one-pot, but multicomponent reaction.…”