90841-69-3Relevant academic research and scientific papers
Electrochemical bromofunctionalization of alkenes in a flow reactor
Seitz, Jakob,Wirth, Thomas
supporting information, p. 6892 - 6896 (2021/08/20)
The bromination of organic molecules has been extensively studied to date, yet there is still a demand for safe and sustainable methodologies. Hazardous reagents, selectivity, low atom economy and waste production are the most persisting problems of brominating reagents. The electrochemical oxidation of bromide to bromine is a viable strategy to reduce waste by avoiding chemical oxidants. Furthermore, thein situgeneration of reactive intermediates minimizes the risk of hazardous reagents. In this work, we investigate the electrochemical generation of bromine from hydrobromic acid in a flow electrochemical reactor. Various alkenes could be converted to their corresponding dibromides, bromohydrines, bromohydrin ethers and cyclized products in good to excellent yields.
Route exploration and synthesis of the reported pyridone-based PDI inhibitor STK076545
Dockendorff, Chris,Flaumenhaft, Robert,Greve, Eric,Lin, Lin,Lindeman, Sergey V.,Scartelli, Christina
, p. 6665 - 6681 (2020/09/21)
The enzyme protein disulfide isomerase (PDI) is essential for the correct folding of proteins and the activation of certain cell surface receptors, and is a promising target for the treatment of cancer and thrombotic conditions. A previous high-throughput screen identified the commercial compound STK076545 as a promising PDI inhibitor. To confirm its activity and support further biological studies, a resynthesis was pursued of the reported β-keto-amide with an N-alkylated pyridone at the α-position. Numerous conventional approaches were complicated by undesired fragmentations or rearrangements. However, a successful 5-step synthetic route was achieved using an aldol reaction with an α-pyridone allyl ester as a key step. An X-ray crystal structure of the final compound confirmed that the reported structure of STK076545 was achieved, however its lack of PDI activity and inconsistent spectral data suggest that the commercial structure was misassigned.
One-pot synthesis of α-bromo- and α-azidoketones from olefins by catalytic oxidation with in situ-generated modified IBX as the key reaction
Chandra, Ajeet,Parida, Keshaba Nanda,Moorthy, Jarugu Narasimha
supporting information, p. 5827 - 5832 (2017/09/09)
Simple one-pot protocols for the syntheses of α-bromoketones and α-azidoketones starting from olefins have been developed by employing catalytic oxidation of the intermediary bromohydrins with in situ-generated modified IBX as the key reaction. The improved procedure involves initial formation of bromohydrin by the reaction of olefin with NBS in acetonitrile-water mixture (1:1) at rt followed by oxidation with in situ-generated 3,4,5,6-tetramethyl-2-iodoxybenzoic acid (TetMe-IBX), produced in catalytic amounts from 3,4,5,6-tetramethyl-2-iodobenzoic and Oxone. α-Bromoketones are further converted in the same pot to the corresponding α-azidoketones using NaN3/NaHCO3. The one-pot conversions are versatile for a variety of olefins that include cyclic as well as acyclic aliphatic olefins and electron-rich and electron-deficient styrenes. Chemoselective bromohydroxylation of electron-rich double bond and subsequent oxidation to the α-bromoketone is demonstrated for a substrate that contains both electron-rich and deficient double bonds.
Regio-and stereoselective hydroxybromination and dibromination of olefins using ammonium bromide and oxone
MacHarla, Arun Kumar,Chozhiyath Nappunni, Rohitha,Nama, Narender
supporting information; experimental part, p. 1401 - 1405 (2012/04/04)
An efficient protocol for the synthesis of vicinal bromohydrins and dibromides from olefins is presented. Various olefins are regio-and stereoselectively hydroxybrominated and dibrominated with anti fashion, following Markonikov's rule, using eco-friendly, non-toxic, and stable reagents such as NH4Br and oxone in CH3CN/H2O (1:1) and CH3CN without employing catalyst in moderate to excellent yields. Bromohydrins are formed instantaneously.
Highly regio- and diastereoselective halohydroxylation of olefins: A facile synthesis of vicinal halohydrins
Zhang, Jinglei,Wang, Jie,Qiu, Zhuibai,Wang, Yang
experimental part, p. 6859 - 6867 (2011/10/02)
An efficient method for the synthesis of vicinal chlorohydrin or bromohydrin derivatives has been developed on the basis of direct halohydroxylation of various olefins with electrondonating or withdrawing substituent. The reactions were carried out under mild conditions in the presence of N-tosyl-l-threonine (NTsLT) as an acidic additive using chloramine T trihydrate, 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) or N-bromoacetamide (AcNHBr) as the halogen source, respectively, affording the corresponding vicinal halohydrins in good to high yields with excellent regio- and stereoselectivities.
Organocatalysis in the stereoselective bromohydrin reaction of alkenes
Bar, Sukanta
experimental part, p. 605 - 612 (2010/08/21)
An efficient regio- and stereo-selective (>99:1) trans-bromohydrination (bromohydroxylation and bromomethoxylation) of alkenes including α,β-unsaturated carbonyl compounds with N-bromosuccinimide (NBS) has been achieved by using 1.0 mol% of N,N'-diarylthi
Comparative study of the vicinal functionalization of olefins with 2:1 bromide/bromate and iodide/iodate reagents
Agrawal, Manoj K.,Adimurthy, Subbarayappa,Ganguly, Bishwajit,Ghosh, Pushpito K.
supporting information; experimental part, p. 2791 - 2797 (2009/08/08)
A comparative evaluation was made on the syntheses of vicinal halohydrins, halo methyl ethers, and halo acetates from olefins using 2:1 Br-/BrO3- and I-/IO3- reagents. In many cases both reagents afforded products selectively in high yields. The highest halogen atom efficiencies attained were 97% and 93% for Br-/BrO3- and I-/IO3-, respectively. Of the two reagents, I-/IO3- was established to be the preferred reagent for vicinal functionalization of linear alkenes and also for halo acetate preparation. However, only Br-/BrO3- was effective for vicinal functionalization of trans-stilbene and chalcones.
A simple and efficient method for regioselective and stereoselective synthesis of vicinal bromohydrins and alkoxybromides from an olefin
Phukan, Prodeep,Chakraborty, Pranita,Kataki, Dolly
, p. 7533 - 7537 (2007/10/03)
(Chemical Equation Presented) A very rapid and efficient method has been developed for the synthesis of vicinal bromohydrins and alkoxybromides directly from an olefin without any catalyst. The reaction was performed in CH 3CN-water (4:1) or alcohol using N,N-dibromo-p-toluenesulfonamide (TsNBr2) as the brominating agent. Excellent yields and regio- and stereoselectivities have been obtained. Bromohydrins are formed instantaneously, whereas formation of alkoxybromides takes 30-60 min.
Effect of cyclodextrin complexation in bromine addition to unsymmetrical olefins: Evidence for participation of cyclodextrin hydroxyl groups
Manickam, Manickam C. Durai,Annalakshmi, Subramanian,Pitchumani, Kasi,Srinivasan, Chockalingam
, p. 1008 - 1012 (2007/10/03)
Multiple recognition by cyclodextrin in a bimolecular reaction, namely bromination of styrene, methyl cinnamate, phenylacetylene and allylbenzene, has been studied. Bromohydrin is obtained as a major product along with dibromide in the bromination of styrene and methyl cinnamate. The percentage of bromohydrin decreases as the cavity size increases. With phenylacetylene, bromophenylacetylene and phenacyl bromide are obtained in addition to the dibromides. In the bromination of cyclodextrin complexes of allylbenzene, the product distribution is the same as in solution bromination. The observed results demonstrate the efficiency of cyclodextrin in stabilizing the open carbocationic intermediate and thus provide chemical evidence for the participation of cyclodextrin hydroxyl groups. The Royal Society of Chemistry 2005.
Synthesis of bromo- And iodohydrins from deactivated alkenes by use of N-Bromo- and W-iodosaccharin
Urankar, Damijana,Rutar, Irena,Modec, Barbara,Dolenc, Darko
, p. 2349 - 2353 (2007/10/03)
N-Bromo and N-iodosaccharin react with electron-deficient alkenes such as α,β-unsaturated ketones, acids, esters and nitriles in aqueous organic solvents, yielding the corresponding halohydrins in good yields. The reactions take place at room temperature,
