6626-15-9Relevant academic research and scientific papers
Regioselective bromination of arenes mediated by triphosgene-oxidized bromide
Xu, Yingzhou,Hu, Dufen,Zheng, Hui,Mei, David,Gao, Zhaobo
supporting information, (2019/08/30)
This article first time describes triphosgene (BTC) as an oxidant while the non-toxic and easy-to-handle potassium bromide (KBr) as the source of bromine to the bromination reaction of aromatic substrates. The novel brominating protocol gives excellent para-regioselectivity of the alkoxyl/hydroxyl arenes and high yield, offering good potential of commercial scale applications. The mechanism of “Triphosgene oxidize bromide” was proposed.
Polymer-anchored [Fe(III)Azo] complex: An efficient reusable catalyst for oxidative bromination and multi-components reaction for the synthesis of spiropiperidine derivatives
Khatun, Resmin,Biswas, Surajit,Ghosh, Swarbhanu,Islam, Sk. Manirul
, p. 37 - 46 (2018/02/03)
A heterogeneous catalyst was prepared by attaching Fe(III) into organically modified chloromethylated polytstyrene and characterized by AAS, IR, PXRD, TG-DTA, UV–Vis, and SEM studies. In presence of H2O2 and KBr as bromine source, the catalyst showed remarkably high conversion with para-selectivity towards the oxidative bromination reaction in acetic acid medium. The catalyst was also very active and highly efficient for the production of spiropiperidine derivatives through multi-component reaction in isopropyl alcohol at room temperature. The catalyst was not leached during the catalytic reactions, moreover, after five cycles the catalytic activity and selectivity of the catalyst were not decreased very significantly.
Practical regioselective halogenation of vinylogous esters: Synthesis of differentiated mono-haloresorcinols and polyhalogenated resorcinols
Chen, Xiaohong,Liu, Xiaoguang,Martinez, Jenny S.,Mohr, Justin T.
, p. 3653 - 3665 (2016/06/06)
A practical and efficient method for the direct, regioselective conversion of vinylogous esters to haloresorcinols is reported. Control of the reaction conditions enables synthesis of either the 4- or 6-haloresorcinol isomers from a common precursor with excellent regiocontrol and high yield. The generality and functional group tolerance of this novel protocol is demonstrated. The utility of this methodology to access polyhaloresorcinols is also reported. These methods create useful functionalized building blocks for further synthetic applications.
Enantioselective synthesis, stereochemical correction, and biological investigation of the rodgersinine family of 1,4-benzodioxane neolignans
Pilkington, Lisa I.,Barker, David,Wagoner, Jessica,Polyak, Stephen J.
supporting information, p. 1046 - 1049 (2015/03/30)
The enantioselective synthesis and chiroptic analysis of all members of the rodgersinine family of 1,4-benzodioxane neolignans has been achieved. ECD spectra and optical rotation analysis determined that the previously published stereochemistry of trans-rodgersinines A and B was incorrect. The cis-rodgersinines A and B did not follow the model ECD study commonly used to assign the absolute stereochemistry of 1,4-benzodioxane natural products. This finding has implications on the absolute stereochemistry of other natural products of this type. Additionally, the rodgersinines were found to have anti-HCV activities.
Candida antarctica lipase B-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxy groups
Miyazawa, Toshifumi,Hamada, Manabu,Morimoto, Ryohei
, p. 44 - 49 (2016/01/16)
Candida antarctica lipase B proved to be highly active in the deacylation of substituted hydroquinones and resorcinols acylated at both phenolic hydroxy groups. The deacylation reactions were much faster than the corresponding direct acylations of these dihydroxybenzenes catalyzed by the same lipase. More importantly, they took place generally in a markedly regioselective manner: the acyloxy group remote from the substituent was preferentially cleaved. The main or exclusive products obtained were the regioisomers of those produced through the direct acylation of the dihydroxybenzenes. In the case of alkyl-substituted hydroquinone derivatives, the regioselectivity increased with an increase in the bulk of the substituent. In the case of 4-substituted diacylated resorcinols, the 3-O-monoacyl derivatives were obtained generally as the sole products. Quite interestingly, some secondary alcohols proved to act as better acyl acceptors than the corresponding primary alcohols in these enzymatic deacylations.
Aerobic oxidation and oxidative bromination in aqueous medium using polymer anchored oxovanadium complex
Islam, Sk. Manirul,Molla, Rostam Ali,Roy, Anupam Singha,Ghosh, Kajari,Salam, Noor,Iqubal, Md. Asif,Tuhina
, p. 169 - 178 (2014/05/06)
Polymer anchored oxovanadium catalyst was synthesized and characterized. Its catalytic activity was evaluated for the oxidation of various primary and secondary alcohols with molecular oxygen under mild reaction conditions. This catalyst was also effective for the oxidative bromination reaction of organic substrates with 90-100% selectivity of mono substituted products with H 2O2/KBr at room temperature. The above reactions require low temperature, short time period and most importantly all the above reactions occur in aqueous medium. The developed catalyst can be facilely recovered and reused six times without significant decrease in activity and selectivity. 2014 Elsevier B.V. All rights reserved.
Polymer-anchored peroxo compounds of molybdenum and tungsten as efficient and versatile catalysts for mild oxidative bromination
Boruah, Jeena Jyoti,Das, Siva Prasad,Borah, Rupam,Gogoi, Sandhya Rani,Islam, Nashreen S.
, p. 246 - 254 (2013/05/23)
A polymer supported peroxomolybdate(VI) compound of the type [MoO 2(O2)(CN)2]-PAN [PAN = poly(acrylonitrile)] (PANMo) was obtained by reacting H2MoO4 with 30% H 2O2 and the macromolecular ligand, PAN at near neutral pH. The macrocomplex has been characterized by elemental analysis (CHN and EDX analysis), spectral (IR, UV-Vis and 13C NMR, 95Mo NMR), thermal (TGA-DTG) as well as SEM studies. The catalytic activity of PANMo and its previously reported tungsten containing analog PANW, in oxidative bromination of organic substrates has been explored. The supported complexes could serve as efficient heterogeneous catalysts for the oxidative bromination of a variety of structurally diverse aromatic compounds, with H 2O2 as terminal oxidant, to afford bromo organics in impressive yields under environmentally clean conditions. The catalysts afforded regeneration and could be reused for a minimum of six reaction cycles.
Poly(4-vinylpyridinium bromochromate): An efficient reagent for bromination of aromatic compounds
Albadi, Jalal,Tajik, Hassan,Keshavarz, Mosadegh,Abedini, Masoumeh
, p. 179 - 181 (2013/07/27)
A simple and efficient method for the bromination of various aromatic compounds by using poly(4-vinylpyridinium bromochromate) is reported. This method has several advantages such as good selectivity between ortho and para positions of aromatic compounds, simple workup, short reaction times, and high yields of the products.
Polymer-anchored Cu(II) complex as an efficient catalyst for selective and mild oxidation of sulfides and oxidative bromination reaction
Islam, Sk. M.,Roy, Anupam Singha,Mondal, Paramita,Salam, Noor,Paul, Sumantra
, p. 225 - 233 (2013/03/13)
A new polymer-anchored Cu(II) complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as oxidant. Sulfides have been selectively oxidized to corresponding sulfoxides in excellent yields and in presence of KBr as bromine source, organic substrates have been selectively converted to mono bromo substituted compounds. The polymer-anchored Cu(II) catalyst could be easily recovered by simple filtration and reused more than six times without appreciable loss of its initial activity. Graphical Abstract: [Figure not available: see fulltext.]
Fast and efficient bromination of aromatic compounds with ammonium bromide and Oxone
Naresh, Mameda,Arun Kumar, Macharla,Mahender Reddy, Marri,Swamy, Peraka,Nanubolu, Jagadeesh Babu,Narender, Nama
, p. 1497 - 1504 (2013/06/27)
A highly efficient, rapid and regioselective protocol was developed for the ring bromination of aromatic compounds under mild conditions with ammonium bromide as a source of bromine source and Oxone (potassium peroxysulfate) as an oxidant. No metal catalyst or acidic additive is required. A variety of aromatic compounds, including methoxy, hydroxy, amino, and alkyl arenes, reacted smoothly to give the corresponding monobrominated products in good to excellent yields in very short reaction times. Moreover, dibromination of deactivated anilines to give the corresponding dibromides proceeded in high yields. Interestingly, 1-(2-naphthyl)ethanone provided a ring-brominated product. Georg Thieme Verlag Stuttgart . New York.
