A range of heterocycles, namely thiazoles, imidazoles, imidazopyridines, thiazolidines and dimethoxyindoles, have been synthesised directly from alkenes via a two-step ketoidoination/cyclisation protocol. The alkene starting materials are themselves readily accessible using many different and well-established approaches, and allow access to a variety of heterocycles with excellent yields and re...

Three-component couplings were achieved from common aryl halides, alkyl halides, and heteroarenes under palladium and norbornene co-catalysis. The reaction forges hindered aryl-heteroaryl bonds and introduces ortho-alkyl groups to aryl rings. Various heterocycles such as oxazoles, thiazoles and thiophenes underwent efficient coupling. The heteroarenes were deprotonated in situ by bases without ...

Ten 2-substituted 4-thiazolecarboxaldehyde hydrazones bearing 5-nitro-2-furyl, 5-nitro-2-thiazolyl, and 1-methyl-5-nitro-2-imidazolyl functions have been prepared and screened for activity against Trypanosoma cruzi infections in mice. The results permitted the ranking of these substituents in decreasing order of activity: 1-methyl-5-nitro-2-imidazolyl greater than 5-nitro-2-furyl greater than 5...

Palladium-catalyzed amidation of five-membered heterocyclic bromides that contain multiple heteroatoms was achieved for the first time using the Pd/1 catalyst system. This system allows for efficient access to N-arylated imidazoles, pyrazoles, thiazoles, pyrroles, and thiophenes in moderate to excellent yield. Experimental results and DFT calculations point to the need for electron-rich and esp...

ABSTRACT Some reactions of selected chlorooxoesters and haloesters with a 1-allylthiourea under various conditions have been performed. The reactions have been performed in methanol in alkaline and neutral environment. Condensation of 1-allylthiourea with chlorooxoesters has been further led via acetal as intermediate compound. As a result, the compounds containing thiazole and a 4,5-dihydrothi...

Cyclocondensation of 2-[bis(methylthio)methylene]malononitrile (1) and cysteamine (2) afforded 2-(thiazolidin-2-ylidene)malononitrile (3). This compound on treatment with NaSH gave the corresponding thioamide derivative 4a in a regioselective manner on the basis of its single crystal X-ray diffraction analysis. Reaction of this compound with several alpha-bromocarbonyl compounds gave new 2-(E)-...

Plantazolicin A, a linear decacyclic natural product, exhibits desirable selective activity against the causative agent of anthrax toxicity. The total synthesis of plantazolicin A and its biosynthetic precursor plantazolicin B was successfully achieved by an efficient, unified, and highly convergent route featuring dicyclizations to form 2,4-concatenated oxazoles and the mild synthesis of thiaz...

The mechanisms for photochemical isomerization reactions are studied theoretically using three model systems: 3-methylisothiazole, 4-methylisothiazole and 5-methylisothiazole. The CASSCF (ten-electron/seven-orbital active space) and MP2-CAS methods are used with the 6-311G(d) and 6-311++G(3df,3pd) basis sets, respectively. Three mechanisms, the internal cyclization-isomerization route (path A),...