Fast Microwave-Assisted Resolution of (±)-Cyanohydrins Promoted by Lipase fromCandida antarctica
摘要:
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 92% ee(p)) as well as conversion was achieved under MW radiation (50-56%).
Zinc Tetrafluoroborate-Catalyzed Efficient Conversion of Aldehydes to Geminal Diacetates and Cyanoacetates
作者:Brindaban C. Ranu、Jyotirmoy Dutta、Arijit Das
DOI:10.1246/cl.2003.366
日期:2003.4
A trace of an aqueous solution of zinc tetrafluoroborate was demonstrated to catalyze the conversion of an aldehyde to its 1,1-diacetate by acetic anhydride without any solvent. A similar reaction of an aldehyde with a mixture of potassium cyanide and acetic anhydride in methylene chloride was also catalyzed by Zn(BF4)2 to provide the corresponding geminal cyanoacetate.
TBD- or PS-TBD-Catalyzed One-Pot Synthesis of Cyanohydrin Carbonates and Cyanohydrin Acetates from Carbonyl Compounds
作者:Satoru Matsukawa、Junya Kimura、Miki Yoshioka
DOI:10.3390/molecules21081030
日期:——
Cyanation reactions of carbonylcompounds with methyl cyanoformate or acetyl cyanide catalyzed by 5 mol % of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) were examined. Using methyl cyanoformate, the corresponding cyanohydrin carbonates were readily obtained in high yield for aromatic and aliphatic aldehydes and ketones. Similar results were obtained when acetyl cyanide was used as the cyanide source.
IMPROVED THREE-COMPONENT LEWIS ACID-FREE APPROACH FOR THE SYNTHESIS OF PROTECTED RACEMIC CYANOHYDRINS
作者:G. Kumaraswamy、K. Ankamma
DOI:10.1080/00304940809458105
日期:2008.10
Catalytic, asymmetric synthesis of α-acetoxy amides
作者:Michael North、Adrian W. Parkins、Atiya N. Shariff
DOI:10.1016/j.tetlet.2004.08.114
日期:2004.10
Non-racemic cyanohydrin acetates are readily available from aldehydes and potassium cyanide/acetic anhydride by use of bimetallic titanium (salen) catalyst 1. Treatment of the cyanohydrin acetates with a platinum(II) phosphinito catalyst 3 under neutral conditions results in chemoselective hydrolysis to the corresponding alpha-acetoxy amides in a racemization free process. (C) 2004 Elsevier Ltd. All rights reserved.