Intramolecular Heck Reaction on Bromobenzyloxy-Substituted Chromenes: Formation of Chelated Ketones
TL;DR: In this paper, the Heck reaction on 2-bromobenzyloxy-substituted 4H-chromene derivatives using Pd(OAc)2 in Aliquat 336 and N,N-dimethylformamide mixture leads to intramolecular heteroannulation along with hydrolysis, affording chelated 6H-benzo[c]chromen-2-yl ketones.
About: This article is published in Synthetic Communications.The article was published on 2013-03-06. It has received 5 citations till now. The article focuses on the topics: Heck reaction & Regioselectivity.
Citations
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TL;DR: In this study, the one-pot three-component synthesis of 2-amino-4H-chromenes was accomplished by supramolecular catalysis using a series of well-designed amino-appended β-cyclodextrins (ACDs) in water.
37 citations
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TL;DR: In this article, a magnetically recoverable Fe3O4@SiO2−BenzIm-Fc[Cl]/BiOCl nano-composite was synthesized using a simple chemical co-precipitation method.
Abstract: In this study, a novel magnetically recoverable Fe3O4@SiO2–BenzIm-Fc[Cl]/BiOCl nano-composite was synthesized using a simple chemical co-precipitation method. This is the first time that a magnetic nano-catalyst bearing ionic liquid, ferrocene and BiOCl is synthesized. The Fe3O4@SiO2–BenzIm-Fc[Cl]/BiOCl nano-composite was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FE-SEM) techniques. The catalytic activities of the novel magnetic nano-composite were evaluated in one-pot three-component synthesis of a wide variety of 2-amino-3-cyano-4H-chromene derivatives under ultrasound irradiation. A simple, facile and highly efficient ultrasound-assisted method was developed to synthesize 4H-chromene derivatives via one-pot, three-component reaction of aldehyde, malononitrile and active phenolic compounds (2-naphthol, 1-naphthol, 3-(dimethylamino)phenol, resorcinol and orcinol) at room temperature. The reaction of aldehyde, malononitrile and orcinol is newly introduced in this paper. The ultrasound-assisted synthesis protocol that was studied in this article exhibits some notable advantages such as short reaction times, operational simplicity, green reaction conditions, high yields and easy work-up and purification steps. In addition, the novel magnetic nano-composite could be easily recovered by an external magnetic field and reused for six-reaction cycles without significant loss of its catalytic activity.
28 citations
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TL;DR: A series of polyalkoxy substituted 7-hydroxy- and 7-methoxy-4-aryl-4H-chromenes evaluated using the sea urchin embryo model yielded several compounds exhibiting potent antimitotic microtubule destabilizing activity.
17 citations
References
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TL;DR: A simple, clean, environmentally benign route to the synthesis of 2-amino-chromenes is described using K2CO3 as a green catalyst in water under microwave irradiation, implying a convenient route avoiding the usage of hazardous organic solvents and organic bases.
383 citations
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TL;DR: Brønsted acid-base ionic liquids based on guanidine and acetic acid are efficient reaction media for palladium-catalyzed Heck reactions and play multiple roles in the reaction: it could act as solvent, as a strong base to facilitate beta-hydride elimination, and as a ligand to stabilize activated Pd species.
131 citations
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TL;DR: Yttrium(III) nitrate hexahydrate [Y(NO3)3.6H2O] as a catalyst for organic reaction is described for the first time in this article.
Abstract: Yttrium(III) nitrate hexahydrate [Y(NO3)3.6H2O] as a catalyst for organic reaction is described for the first time. The catalytic activity is demonstrated using Biginelli reaction as a model under solvent-free conditions. Excellent yields of dihydropyrmidinones are obtained at 70 °C within a short reaction time (10–50 min) and the catalyst is also recyclable. Other advantages over the classical method include greater substrate compatibility, faster reaction rates and easy workup procedures.
86 citations