نتایج جستجو برای: ortho diphenols

تعداد نتایج: 6442  

Journal: :The Journal of organic chemistry 2011
Hong Chen Fuchun Xie Jian Gong Youhong Hu

A base-promoted one-pot tandem reaction sequence has been developed to transform electron-deficient chromone-fused dienes 1 and 1,3-dicarbonyl compounds 2 to functionalized 2-hydroxybenzophenones 3 under mild conditions. This domino process, which involves multiple reactions, including Michael addition/cyclization/elimination, serves as an efficient, economic, and eco-friendly method for the co...

Journal: :Journal of Porphyrins and Phthalocyanines 2021

Increasing the number of meso-methine carbons porphyrin has led to a creation series vinylogous expanded porphyrins, while introduction an ortho-phenylene-unit as pyrrole-connecting two-carbon bridge usually leads prevention effective macrocyclic conjugation. Cyclopentene can serve conjugative increase conjugation owing its cis-geometry. In this work, ortho-phenylene-cyclopentene-bridged tetrap...

Journal: :Science 2014
Antonio J Martínez-Martínez Alan R Kennedy Robert E Mulvey Charles T O'Hara

The regioselectivity of deprotonation reactions between arene substrates and basic metalating agents is usually governed by the electronic and/or coordinative characteristics of a directing group attached to the benzene ring. Generally, the reaction takes place in the ortho position, adjacent to the substituent. Here, we introduce a protocol by which the metalating agent, a disodium-monomagnesi...

2018
Zi Liu Hui Xu Guan-Wu Wang

A solvent-free palladium-catalyzed ortho-iodination of acetanilides using N-iodosuccinimide as the iodine source has been developed under ball-milling conditions. This present method avoids the use of hazardous organic solvents, high reaction temperature, and long reaction time and provides a highly efficient methodology to realize the regioselective functionalization of acetanilides in yields ...

2017
Claire M Wilson Venkataraman Ganesh Adam Noble Varinder K Aggarwal

The coupling of ortho- and para-phenols with secondary and tertiary boronic esters has been explored. In the case of para-substituted phenols, after reaction of a dilithio phenolate species with a boronic ester, treatment with Ph3 BiF2 or Martin's sulfurane gave the coupled product with complete enantiospecificity. The methodology was applied to the synthesis of the broad spectrum antibacterial...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
Cyrille Costentin Guillaume Passard Marc Robert Jean-Michel Savéant

A very efficient electrogenerated Fe(0) porphyrin catalyst was obtained by substituting in tetraphenylporphyrin two of the opposite phenyl rings by ortho-, ortho'-phenol groups while the other two are perfluorinated. It proves to be an excellent catalyst of the CO2-to-CO conversion as to selectivity (the CO faradaic yield is nearly quantitative), overpotential, and turnover frequency. Benchmark...

Journal: :Physical review letters 2013
E Blackburn J Chang M Hücker A T Holmes N B Christensen Ruixing Liang D A Bonn W N Hardy U Rütt O Gutowski M von Zimmermann E M Forgan S M Hayden

X-ray diffraction measurements show that the high-temperature superconductor YBa2Cu3O6.54, with ortho-II oxygen order, has charge-density-wave order in the absence of an applied magnetic field. The dominant wave vector of the charge density wave is q(CDW)=(0,0.328(2),0.5), with the in-plane component parallel to the b axis (chain direction). It has a similar incommensurability to that observed ...

Journal: :Journal of the American Chemical Society 2010
Joann M Um Osvaldo Gutierrez Franziska Schoenebeck K N Houk David W C MacMillan

The intramolecular alpha-arylation of aldehydes via organo-SOMO catalysis was investigated using density functional theory (B3LYP and M06-2X functionals). The geometries, spin densities, Mulliken charges, and molecular orbitals of the reacting enamine radical cations were analyzed, and the nature of the resulting cyclized radical cation intermediates was characterized. In agreement with experim...

Journal: :Applied and environmental microbiology 2004
Werner E G Müller Vladislav A Grebenjuk Narsinh L Thakur Archana N Thakur Renato Batel Anatoli Krasko Isabel M Müller Hans J Breter

Sponges (phylum Porifera), known to be the richest producers among the metazoans of bioactive secondary metabolites, are assumed to live in a symbiotic relationship with microorganisms, especially bacteria. Until now, the molecular basis of the mutual symbiosis, the exchange of metabolites for the benefit of the other partner, has not been understood. We show with the demosponge Suberites domun...

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