61066-87-3Relevant academic research and scientific papers
Fast microwave-assisted resolution of (±)-cyanohydrins promoted by lipase from Candida antarctica
Ribeiro, Sandra S.,Ferreira, Irlon M.,Lima, Jo?o P. F.,De Sousa, Bruno A.,Carmona, Rafaela C.,Santos, Alcindo A. Dos,Porto, André L. M.
, p. 1344 - 1350 (2015/07/15)
Enzymatic kinetic resolution (EKR) of (±)-cyanohydrins was performed by using immobilized lipase from Candida antarctica (CALB) under conventional ordinary conditions (orbital shaking) and under microwave radiation (MW). The use of microwave radiation contributed very expressively on the reduction of the reaction time from 24 to 2 h. Most importantly, high selectivity (up to 92percent eep) as well as conversion was achieved under MW radiation (50-56percent).
One-pot three components synthesis of O-acetylcyanohydrins with TMSCN, acetic anhydride and carbonyl compounds under solvent-free condition
Kadam, Santosh T.,Kim, Sung Soo
experimental part, p. 6330 - 6334 (2010/01/06)
One-pot three components synthesis of O-acetylcyanohydrins has been developed in the presence of B(C6F5)3 as the catalyst. Variety of aldehydes or ketones reacts with TMSCN and acetic anhydride (Ac2O) under the
Solvent-free synthesis of cyanohydrin derivatives catalysed by triethylamine
Baeza, Alejandro,Najera, Carmen,Retamosa, Ma. De Gracia,Sansano, Jose M.
, p. 2787 - 2797 (2007/10/03)
A very simple one-step environmentally friendly procedure for the synthesis of O-substituted cyanohydrins from aldehydes and ketones, in the absence of solvent, employing minimum amounts of the corresponding cyanides has been optimised. Aldehydes react more rapidly than ketones using triethylamine as catalyst offering in both cases almost quantitative yields of the corresponding O-trimethylsilyl, O-methoxycarbonyl, O-benzoyl and O-acetyl cyanohydrins. Georg Thieme Verlag Stuttgart.
CAL-B catalyzed enantioselective synthesis of cyanohydrins - A facile route to versatile building blocks
Hanefeld,Li,Sheldon,Maschmeyer
, p. 1775 - 1776 (2007/10/03)
A straightforward process for the preparation of optically active cyanohydrins, important building blocks for the synthesis of drugs and agrochemicals, has been established. Lipase B from Candida antarctica (CAL-B) catalyzes the kinetic resolution of racemic cyanohydrin acetates under mild conditions: optimization of the process led to a user-friendly synthesis of (S)- and (R)-cyanohydrins.
Chemo-enzymatic synthesis of (S)-α-cyano-3-phenoxybenzyl alcohol
Fishman, Ayelet,Zviely, Michael
, p. 107 - 118 (2007/10/03)
A chemo-enzymatic process for the preparation of (S)-α-cyano-3- phenoxybenzyl alcohol (S-CPBA), an important intermediate in the synthesis of many pyrethroids, was developed. The process consists of four stages, including lipase-mediated resolution. The first stage, the synthesis of racemic α-cyano-3-phenoxybenzyl acetate (CPBAc) from m-phenoxybenzaldehyde (m-PBA) and sodium cyanide in the presence of a phase transfer catalyst, resulted in a 75% yield with 95% purity. The second key step is the resolution of the racemic ester by a highly enantioselective lipase from Pseudomonas sp. The immobilized enzyme carried out the transesterification reaction to nearly full conversion (46% out of 50%) with an enantiomeric excess of >96%. The enzymatic reaction was accomplished in a batch system as well as in a fluidized bed column. The reaction was found to be inhibited by accumulation of the product and to a lesser extent, by the aldehyde. The separation of the enantiomerically pure alcohol from the undesired ester was performed by chromatographic techniques, as well as by extraction with hexane. The final racemization step of the (R)-ester was easily attained with the use of triethylamine in diisopropyl ether or toluene. The process was shown to be feasible on a gram scale and shows potential for scale up.
Attempted Enantioselective Synthesis of Terbutaline. Unexpected Partial Racemization During Lithium Aluminium Hydride Reduction of a Secondary Amide
Donohue, Andrew C.,Jackson, W. Roy
, p. 1741 - 1746 (2007/10/03)
Syntheses leading to compounds related to the brobchodilator (-)-terbutaline via optically active cyanohydrins suffered unexpected partial racemization during lithium aluminium hydride reduction of key amide intermediates.
Enantioselective Hydrolysis of α-Cyano-3-phenoxybenzyl Acetate with Arthrobacter Lipase
Mitsuda, Satoshi,Yamamoto, Hidefumi,Umemura, Takeaki,Hirohara, Hideo,Nabeshima, Shigeyasu
, p. 2907 - 2912 (2007/10/02)
Lipase-catalyzed enantioselective hydrolysis of the acetic ester of racemic α-cyano-3-phenoxybenzyl alcohol (CPBA) was examined to prepare (S)-CPBA.Most of the lipases tested hydrolyzed (S)-CPBA acetate preferentially, while Candida cylindracea lipase favored (R)-CPBA acetate.Enantioselective hydrolysis by Arthrobacter lipase gave optically pure (S)-CPBA in the reaction mixture of pH 4.0.The kinetic studies showed that (R)-CPBA acetate reacted as a competitive inhibitor.The Arthrobacter lipase solution in the water/oil biphasic reaction system could be usedrepeatedly.The lipase immobilized to resins had insufficient activity or low operational stability with the repeated batch reaction.The unhydrolyzed (R)-CPBA acetate was racemized by heating with triethylamine and could be reused as the substrate of enzymatic hydrolysis.A chemico-enzymatic process for the preparation of (S)-CPBA was developed based on these studies.
Process for preparing cyanohydrin esters
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, (2008/06/13)
Cyanohydrin esters are prepared by forming a mixture of an acyl cyanide, a carboxylic acid anhydride and an alkali metal borohydride and reacting the mixture at a temperature and for a time sufficient to form the cyanohydrin ester product of the acyl cyan
