Synthesis of imidazo[1,2-c]thiazoles through Pd-catalyzed bicyclization of tert-butyl isonitrile with thioamides

Abstract

We report herein the synthesis of imidazo[1,2-c]thiazoles through a Pd-catalyzed insertion reaction of three isonitrile molecules and cascade bicyclization in a one-pot, two-step process.

Synthesis and Applications of Imidazothiazoles: An Overview

“…Veltri and co-workers have developed a methodology for divergent multicomponent tandem Palladium-catalysed aminocarbonylation-cyclisation approach towards functionalized imidazothiazoles (150, 152). [23] They carried out the palladiumcatalysed oxidative aminocarbonylation of 2-(prop-2-ynyl thio) imidazoles (147), under the condition of PdI 2 /KI, O 2 , CO and a secondary amine (148, 151)…”

“…[22] Derivatives of imidazo [1,2-c]thiazoles could act as HIV-1 RT inhibitors. [23] All these attest the importance of these moieties in medicinal chemistry. Naturally, the syntheses of these scaffolds are of paramount importance in organic synthesis.…”

Three-Component Domino Reaction of Thioamide, Isonitriles, and Water: Selective Synthesis of 1,2,4-Thiadiazolidin-3-ones and (E)-N-(1,2-Diamino-2-thioxoethylidene)benzamides

“…In 2018, Pan and co-workers developed a multistep cascade reaction of isocyanides and thioamides by using Pd-metalated phosphorus-doped porous organic polymers as heterogeneous catalysts (Scheme a) . Another step forward was taken in 2019 by this research group that described the preparation of the new class of heterobicyclic compounds by Pd-catalyzed cascade bicyclization from isonitriles with thioamides (Scheme b) . Herein, we report the three-component domino reaction of thioamides, isonitriles, and water.…”

“…10 Another step forward was taken in 2019 by this research group that described the preparation of the new class of heterobicyclic compounds by Pd-catalyzed cascade bicyclization from isonitriles with thioamides (Scheme 1b). 11 Herein, we report the three-component domino reaction of thioamides, isonitriles, and water. With the combination of Pd(dppf)Cl 2 and Cu(OAc) 2 , the reaction of thioamides, benzyl isocyanide, and water afforded novel 1,2,4-thiadiazolidin-3-one cyclic compounds, whereas the same reaction with tertiary alkylisonitriles in the presence of rare earth metal salt [La(OTf) 3 ] resulted in the (E)-N- (1,2-diamino-2-thioxoethylidene)benzamide openchain products.…”

Transition-Metal-Catalyzed Diarylation of Isocyanides with Triarylbismuthines for the Selective Synthesis of Imine Derivatives

“…Recently, we developed novel palladium-catalyzed diarylation reactions of isocyanides 2 [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] using triarylbismuthines 1 and tetraarylleads 4 ( Scheme 1 ). The use of BiAr 3 1 result in α -diimines 3 being selectively obtained ( Scheme 1 a) [ 42 ].…”