61092-03-3Relevant academic research and scientific papers
A useful propionate cofactor enhancing activity for organic solvent-tolerant recombinant metal-free bromoperoxidase (perhydrolase) from Streptomyces aureofaciens
China, Hideyasu,Ogino, Hiroyasu
, p. 327 - 332 (2019/07/12)
The oxidative brominating activity of an organic solvent-tolerant recombinant metal-free bromoperoxidase BPO-A1 with C-terminal His-tag (rBPO-A1), from Streptomyces aureofaciens found to depend on various additives. These included carboxylic acids, used as cofactors and alcohols, used as water-miscible organic solvents. Enzyme activity was significantly enhanced by using propanoic acid (PA) as a cofactor, which had a high Log D at pH 5.0 and ethylene glycol with a low Log P. The positional specificity of oxidative hydroxybromination for olefins, using rBPO-A1 and PA in the presence of methanol, was higher compared to a non-enzymatic reaction using peracetic acid. The oxidative bromination step, occurring after enzymatic peroxidation step, is suggested to be pseudoenzymatic.
A simple and facile method for regio- and stereoselective bromoformyloxylation and bromoacetoxylation of olefins using NH4Br and oxone
Naresh, Mameda,Swamy, Peraka,Arun Kumar, Macharla,Mahender Reddy, Marri,Srujana, Kodumuri,Narender, Nama
supporting information, p. 3926 - 3933 (2014/07/08)
A mild and efficient protocol for the preparation of bromoformates as well as bromoacetates from olefins using NH4Br and oxone in nucleophile sources (DMF or DMA) without employing catalyst at room temperature is described. This method is facile, environmentally friendly and cost effective. A variety of terminal, internal and cyclic alkenes reacted smoothly to give the corresponding bromoformate and acetate products in good to excellent yields. Moreover, 1,2-disubstituted olefins provided moderate to excellent diastereoselectivity.
Enzymatic preparation of (1S,2R)- and (1R,2S)-stereoisomers of 2-halocycloalkanols
Kolodiazhna, Olga O.,Kolodiazhna, Anastasy O.,Kolodiazhnyi, Oleg I.
, p. 37 - 42 (2013/02/25)
The stereoisomers of cis-2-halocycloalkanols were resolved by a kinetically controlled transesterification with vinyl acetate in the presence of lipases in organic media. High enantioselectivities (ee >98%) and good isolated yields were obtained for all substrates using the appropriate lipase. Burkholderia cepacia lipase was the most efficient enzyme for the resolution of these substrates. The enantiomeric purities of the compounds were defined by derivatization with Mosher's acid and the absolute configurations were determined by chemical correlation.
Lipase-catalyzed kinetic resolution of 2-methylene-substituted cycloalkanols in batch and continuous-flow modes
Tomin, Anna,Hornyánszky, Gábor,Kupai, Katalin,Dorkó, Zsanett,ürge, László,Darvas, Ferenc,Poppe, László
experimental part, p. 859 - 865 (2011/12/15)
Kinetic resolutions of cyclic racemic secondary alcohols (2-methylenecyclopentan-1-ol rac-1a, 2-methylenecyclohexan-1-ol rac-1b, 2-methylenecycloheptan-1-ol rac-1c, 6-methylene-[1,3]dioxepan-5-ol rac-1d, 2,2-dimethyl-6-methylene-[1,3]dioxepan-5-ol rac-1e and trans-2-bromocyclohexan-1-ol rac-3) catalyzed by different (commercial and in-house-made) lipases were performed using vinyl acetate in THF-hexane. In the most typical cases (rac-1b, rac-1d and rac-3), the immobilized Candida antarctica lipase B (CaLB, for rac-1b and rac-3)- or sol-gel immobilized Pseudomonas fluorescens lipase (sol-gel LAK, for rac-1d)-catalyzed batch mode reactions were compared to the continuous mode reactions carried out in an enzyme-filled stainless steel bioreactor. The effect of temperature (20-60 °C) and flow rate (0.1-0.3 ml min-1) on the continuous-flow acetylation of rac-1b, rac-1d and rac-3 were investigated. In the kinetic resolutions of rac-1b, rac-1d and rac-3, the enantiomeric selectivities (E) were similar in the continuous-flow and batch (shake flask) modes. However, the productivities (specific reaction rate: r), were significantly higher in the continuous-flow mode biotransformations of rac-1b, rac-1d and rac-3.
Iodine(III)-initiated bromoacetoxylation of olefins
Hashem, Md. Abul,Jung, Alexander,Ries, Monika,Kirschning, Andreas
, p. 195 - 197 (2007/10/03)
A new and mild method for the bromoacetoxylation of olefins is presented, which is initiated by iodine(III). α-Acetoxy bromides 6-11 are generated from olefins 5 in the presence of tetraethylammonium bromide (1) and (diacetoxyiodo)benzene (2). The 1,2-addition to carbohydrate-derived enol ethers results in 2-deoxy-2-bromo-pyranosyl acetates which are versatile glycosyl donors for the synthesis of 2′-deoxy-2′-bromo glycosides 16.
Synthesis of an enantiomerically pure aminoisoquinocarbazole with antiarrhythmic activity via lipase-catalyzed enantioselective transesterification
Fukazawa, Tetuya,Shimoji, Yasuo,Hashimoto, Toshihiko
, p. 1649 - 1658 (2007/10/03)
Enantiomerically pure (R)-2-cyclohexen-1-ol 5 was prepared via lipase- catalyzed enantioselective transesterification of 2-substituted cyclohexanol, and stereospecifically converted to (-)-(2-cyclohexenyl)acetic acid 4. Enantiomerically pure aminoisoquinocarbazole 1 (RS-2135) was synthesized stereoselectively from 4, using an intramolecular Diels-Alder reaction and Curtius rearrangement.
Synthesis of enantiomerically pure (R)-2-cycloalken-1-ols using highly enantioselective enzymatic transesterification
Fukazawa,Hashimoto
, p. 2323 - 2326 (2007/10/02)
Optically pure (R)-2-cycloalken-1-ols were synthesized via highly enantioselective lipase-catalyzed transesterification of 2-substituted cycloalkanols.
CIS 1,2-FUNCTIONALIZATION OF CYCLOHEXANE USING SELENIUM INTERMEDIATES
Morella, Angelo M.,Ward, A. David
, p. 2899 - 2900 (2007/10/02)
The trans 1,2-phenylseleno acetate, acetamide, alcohol and nitrile of cyclohexane may be oxidized at selenium by halogens and the phenylseleno moiety displaced by halide to give high yields of 1,2 halide-containing products with cis geometry.
