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A novel process using N-benzylhydroxylamine hydrochloride as a "C1N1 synthon" in [2+2+1] cyclization for the construction of 1,2,5-trisubstituted imidazoles has been described for the first time. The key to realizing this process lies in capturing arylamines by in situ generated novel acyl ketonitrone intermediates. Subsequent tautomerization activates the α-C(sp3)–H of N-benzylhydroxylamines, and thus breaks through its inherent reaction mode and achieves N, α-C site-selective cyclization. Furthermore, this method enables scale-up synthesis and late-stage modification of complex molecules. [ABSTRACT FROM AUTHOR]

A total synthesis strategy was developed for the synthesis of luotonin A, B and their analogues using synergistic FeCl3/KI‐catalyzed oxidative cyclization. This protocol utilizes cheap and widely available N‐propargyl 2‐methyl‐quinazolinones and arylamines under mild conditions, and it has a wide substrate scope and high atom economy. Different natural products (luotonin A, B and derivatives) can be synthesized via a unique switchable approach. Further transformations from luotonin B to luotonin E and structural modification of natural products demonstrate the potential applications of this method. Moreover, camptothecin can also be modified with the reported protocol to afford the hydroxyl‐substituted product. [ABSTRACT FROM AUTHOR]

A DABCO‐promoted bicyclization/rearrangement reaction has been developed for the synthesis of tetrasubstituted furans from 1,4‐enediones at room temperature. This transformation involves aza‐Michael addition, intramolecular bicyclization, and rearrangement processes. In addition, the 4‐ureidofuran‐3‐carboxylate ester products can further be converted to furo[3,4‐d]pyrimidine‐2,4‐diones through intramolecular substitution cyclization under heating conditions. [ABSTRACT FROM AUTHOR]

A I2‐DMSO mediated approach to introduce −OCD3 into pyrroles in situ via multicomponent cascade cyclization reaction using methyl ketones, aniline, ethyl benzoylacetate and CD3OD as readily available substrates is reported. This process realizes introduction of −OCD3 into the Hantzsch pyrrole synthesis and synthesis of deuterated alkoxy‐substituted pyrroles with formation of one C−C bond, one C−O bond and two C−N bonds in one pot. Notably, this conversion has good substrate compatibility (62 examples) and eliminates of the need for anhydrous and anaerobic operation. [ABSTRACT FROM AUTHOR]

Abstract: We herein describe the development of a dimerization procedure for amino acids to prepare 2,5‐disubstituted thiazoles and oxazoles in the presence of Na2S⋅9H2O and H2O, respectively. These approaches enabled the direct formation of five‐membered ring systems bearing two different heteroatoms from two amino acid units. Mechanically, decarboxylation, deamination, S/O insertion, cyclization and gradient oxidation processes were involved in the oligomer formation. [ABSTRACT FROM AUTHOR]

A base-promoted and highly selective temperature-dependent tandem oxidation/decarboxylative cyclization of isothiocyanates and isatins has been developed. This method allows the chemodivergent synthesis of 4 H-benzo[ d][1,3]thiazin-4-ones and 2-thioxo-2,3-dihydroquinazolin-4(1 H)-ones in moderate to high yields. [ABSTRACT FROM AUTHOR]

An I2-promoted formal [3+2] cycloaddition for access to oxazoles has been demonstrated. This is the first example of a Lewis acid-promoted formal [3+2] cycloaddition of isocyanides with methyl ketones involving the C≡N cleavage of isocyanides. The salient feature of this approach is unconventional 2,5-disubstituted oxazole formation from isocyanides and ketones rather than 4,5-substituted oxazoline. [ABSTRACT FROM AUTHOR]

An efficient transition-metal-free cascade reaction has been developed for the facile synthesis of 12H-benzo[4,5]thiazolo[2,3-b]quinazolin-12-one derivatives from commercially available isatins and 2-haloaryl isothiocyanates. A preliminary mechanistic study suggested an interrupted Dimroth rearrangement was the key step for the successful transformation. [ABSTRACT FROM AUTHOR]

Although 2-imino-1 H-imidazol-5(2 H)-ones have important biological activities in metabolism, their synthesis has rarely been investigated. Quinoxalines as 'privileged scaffolds' in medicinal chemistry have been extensively investigated, but the development of novel and efficient synthetic methods remains very attractive. Herein, we have developed two copper-catalyzed domino reactions for the synthesis of 2-imino-1 H-imidazol-5(2 H)-ones and quinoxalines involving CC bond-cleavage with a 1,3-dicarbonyl unit as a leaving group. The domino sequence for the synthesis of 2-imino-1 H-imidazol-5(2 H)-ones includes aza-Michael addition, intramolecular cyclization, CC bond-cleavage, 1,2-rearrangement, and aerobic dehydrogenation reaction, whereas the domino sequence for the synthesis of quinoxalines includes aza-Michael addition, intramolecular cyclization, elimination reaction, and CC bond-cleavage reaction. The two domino reactions have significant advantages including high efficiency, mild reaction conditions, and high tolerance of various functional groups. [ABSTRACT FROM AUTHOR]

Reaction of Na2WO4and NaVO3with cis-Ru(dmso)4Cl2in buffer solution (pH 6) led to the formation of a novel polyanion [HVW7O28Ru(dmso)3]6−(1), which is composed of an unprecedented heptatungstovanadate fragment stabilized by one Ru(dmso)3group. The crystallization of 1with sodium–potassium resulted in Na4K2[HVW7O28Ru(dmso)3]·Na3VO4·15H2O (1a), which exhibits a 3D architecture formed by the polyanion 1and sodium–potassium linkers. [ABSTRACT FROM AUTHOR]

[Display omitted] A highly efficient I 2 -promoted formal [3 + 1 + 2] cyclization has been developed for the synthesis of pyrimido[1,2- b ]indazole from methyl ketones and 1 H -indazol-3-amine using 1,4-dithiane-2,5-diol as an ethylene surrogate. This method enriches the diversity of reactions using 1,4-dithiane-2,5-diol as a C2 synthon to construct nitrogen-containing fused heterocycles. Mechanistic investigations indicated that the reaction occurs via an iodination/Kornblum oxidation/condensation/ aza -Diels-Alder cascade. [ABSTRACT FROM AUTHOR]

A molecular iodine mediated oxidative cross-coupling of β-keto ester sp 3 C–H with 1 H -indole sp 2 C–H was developed for the synthesis of indolo[2,3- b ]carbazoles. A self-sequenced iodination/Kornblum oxidation/hydrolyzation/decarboxylative/deacylation/aromatization mechanism has been proposed as a possible reaction sequence to account for the results observed in this study. [ABSTRACT FROM AUTHOR]

A highlyefficient multicomponent domino protocol has been developedfor the synthesis of 5-phenyl-[1,2,3]triazolo[1,5-c]quinazolines from simple and readily available (E)-1-bromo-2-(2-nitrovinyl)benzenes, aldehydes, andsodium azide. This elegant domino process involved consecutive [3+ 2] cycloaddition, copper-catalyzed SNAr, reduction, cyclization,and oxidation sequences. Notably, sodium azide acted as a dual nitrogensource in the construction of this novel fused N-heterocycle. [ABSTRACT FROM AUTHOR]

An electronic tuning Nazarov-type cyclization protocol was proposed for the synthesis of polysubstituted-1-indanones from the readily available starting materials 1,4-enediones. AlCl 3 was highlighted as the most efficient promoter for this reaction. [ABSTRACT FROM AUTHOR]

A novel method for the construction of diheteroaryl thioethers from aromatic methyl ketones and thiourea is described. Iodine is the unique catalyst in this protocol. The transformation is free of foul-smell thiols and transition metal. In addition, this method could synthesize two thiazole rings and a sulfur bridge in one pot. [ABSTRACT FROM AUTHOR]

Abstract: A novel and attractive protocol to synthesis indole-2,3-diones and 2-hydroxy-3(2H)-benzofuranones and via copper(II) oxide catalyzed intramolecular cyclization is described. This method possesses functional-group compatibility, easy workup procedure, shorter reaction time and high yields. [Copyright &y& Elsevier]

A new method formanganous acetate tetrahydrate mediated formalintermolecular [2 + 2 + 2 + 1] cycloaddition was developed for thesynthesis of fused cycloheptatriene derivatives from N-(acylmethyl)pyridinium iodides and naphthoquinone. Thismethod provides an innovative route for the efficient and convenientconstruction of fused seven-membered carbocycles from simple startingmaterials. [ABSTRACT FROM AUTHOR]

Abstract: An I2-promoted sp3 C–H functionalization has been developed for the synthesis of 2,5-disubstituted oxazoles from easily available methyl ketones and benzylamines without any metal and peroxide catalyst. This domino oxidative cyclization process involves the cleavage of C–H bond and the formation of C–N, C–O bonds. [Copyright &y& Elsevier]

A multipathway coupled domino strategy has been developed for the efficient synthesis of 2-acylbenzothiazoles from multiform substrates arylethenes, arylacetylenes, 2-hydroxy-aromatic ketones, and carbinols via four distinct pathways. Through a logical coupled oxidation/heterocyclization domino process, a variety of 2-acylbenzothiazoles were synthesized free of metal in one pot. [ABSTRACT FROM AUTHOR]

Abstract: A concise and efficient one-pot process from easily available methyl ketones/unsaturated methyl ketones and thiourea was developed for the synthesis of 2-aminothiazoles under the media of I2/CuO. The method can highly stereoselectivity obtain the E-isomers of 4-ethenyl-2-aminothiazoles (5a–f). All these target molecules were characterized by NMR, HRMS and IR spectra. Furthermore, the target compounds 3c and 5b were further determined by X-ray crystallographic analysis. [Copyright &y& Elsevier]

Abstract: The convergent and linear domino reactions have been first integrated, for the first time, to provide an efficient synthesis of indole–furan conjugates from indoles, methyl ketones, and 1,3-dicarbonyl compounds. [Copyright &y& Elsevier]

Reaction of Na2WO4and NaVO3with cis-Ru(dmso)4Cl2in buffer solution (pH 6) led to the formation of a novel polyanion [HVW7O28Ru(dmso)3]6−(1), which is composed of an unprecedented heptatungstovanadate fragment stabilized by one Ru(dmso)3group. The crystallization of 1with sodium–potassium resulted in Na4K2[HVW7O28Ru(dmso)3]·Na3VO4·15H2O (1a), which exhibits a 3D architecture formed by the polyanion 1and sodium–potassium linkers. [ABSTRACT FROM AUTHOR]

An abstract of the article "Acid-Catalyzed Multicomponent Tandem Double Cyclization: A One-Pot, Metal-Free Route to Synthesize Polyfunctional 4,9-Dihydropyrrol(2,1-b)quinazolines" by J.-T. Ma, Y.-D. Wu and A.-X. Wu is presented.

A facile synthesis of various functionalized quinazolinones from commercially available isatins and amidine hydrochlorides is presented. [ABSTRACT FROM AUTHOR]

Simple, readily available starting materials are used for the preparation of the desired alkaloid scaffold under metal-free conditions A) or B). [ABSTRACT FROM AUTHOR]

An abstract of the article "Broensted Acid Promoted Addition-Cyclization and C-C Bond Cleavage: A Convenient Synthesis of 2-Amino-5-aroylmethylthiazoles Derivatives" by Fan Ni and colleagues is presented.

A new method to synthesize indole-2,3-diones and 2-hydroxy-3(2H)-benzofuranones is developed via a one-stop oxidative cyclization of the corresponding ortho-functionalized acetophenones (I) and (III). [ABSTRACT FROM AUTHOR]