RESUMO
A highly efficient method for the synthesis of 2-hydroxy-2,3-dihydrofuran derivatives from 1,4-enediones and phenacyl pyridinium halides via a domino reaction has been developed. This is a simple and beneficial strategy for the construction of 2-hydroxy-2,3-dihydrofuran compounds from readily available starting materials under mild conditions. Moreover, the application of this reaction provides a straightforward and practical route for the synthesis of the novel 4-(1H-pyrazol-4-yl)pyridazine skeleton.
Assuntos
Furanos/química , Hidrocarbonetos Halogenados/química , Cetonas/química , Pirazóis/síntese química , Piridazinas/síntese química , Compostos de Piridínio/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Pirazóis/química , Piridazinas/químicaRESUMO
A Brønsted acid promoted C-C bond cleavage method for the synthesis of novel 2-amino-5-aroylmethylthiazole derivatives has been directly developed from 1,4-enediones and thioureas through self-sequenced thio-Michael-addition, intramolecular selective cyclization, dehydration/aromatization, and C-C bond cleavage reactions. It is noteworthy that this reaction has significant advantages in simple reagents, under environmentally benign conditions and with excellent yields. This highly efficient method is also a highly attractive alternative for the preparation of PLTP, CETP inhibitors and novel biheterocycles.
RESUMO
A transition-metal-free coupling annulation reaction of arynes, ketones, and alkynoates has been demonstrated. Using this formal [2 + 2 + 2] cycloaddition reaction, a wide variety of naphthalene derivatives were conveniently constructed in one pot with high efficiency. In addition, this novel and valid annulation has been successfully applied to the synthesis of 1-phenanthrenol derivatives.
RESUMO
A transition-metal-free multicomponent coupling cyclization reaction was explored involving arynes, tosylhydrazine, and α-bromo ketones. The reaction proceeds via a formal [2 + 2 + 2] cycloaddition, giving access to cinnoline derivatives in moderate yields under mild conditions. Three chemical bonds were formed-two C-N bonds and one C-C bond-in a single step.
Assuntos
Compostos Heterocíclicos com 2 Anéis/química , Hidrocarbonetos Bromados/química , Imidas/química , Cetonas/química , Catálise , Ciclização , Estrutura Molecular , EstereoisomerismoRESUMO
A one-pot acid-mediated reaction has been developed for the N-H/α,ß-C(sp(3))-H trifunctionalization of pyrrolidine without any metallic reagents or external oxidants. This reaction involves the intermolecular [3 + 2] cycloaddition of in situ-generated azomethine ylides with acrylic esters to provide facile access to 2,3-dihydro-1H-pyrrolizine derivatives in high yields under mild conditions.
RESUMO
A transition-metal-free multicomponent benzannulation reaction was developed from readily available ketones, nitro-olefins, and diester acetylenedicarboxylate. This approach provides a straightforward and efficient way to construct polysubstituted benzene derivatives under mild conditions in high yields.
RESUMO
A multicomponent reaction has been developed for the synthesis of polyfunctional pyrazole derivatives from readily available arylglyoxal monohydrates, tosylhydrazine, and aldehydes or ketones. This synthetic method has significant advantages in broad substrate scope, excellent regioselectivity, and simple operation.
Assuntos
Pirazóis/síntese química , Aldeídos/química , Glioxal/análogos & derivados , Glioxal/química , Hidrazinas/química , Cetonas/química , Estrutura Molecular , Pirazóis/química , EstereoisomerismoRESUMO
A new method for manganous acetate tetrahydrate mediated formal intermolecular [2 + 2 + 2 + 1] cycloaddition was developed for the synthesis of fused cycloheptatriene derivatives from N-(acylmethyl)pyridinium iodides and naphthoquinone. This method provides an innovative route for the efficient and convenient construction of fused seven-membered carbocycles from simple starting materials.