An efficient catalytic deprotection of thioacetals employing bismuth triflate: synthesis of pyrrolo[2,1-c] [1,4] benzodiazepines
作者:Ahmed Kamal、P.S.M.M Reddy、D Rajasekhar Reddy
DOI:10.1016/s0040-4039(03)00437-4
日期:2003.3
A simple and efficientdeprotection of thioacetals has been achieved by employing bismuthtriflate. This method has been effectively employed in the preparation of DNA-binding pyrrolo[2,1-c] [1,4]benzodiazepine and its dimers.
通过使用三氟甲磺酸铋已经实现了对硫缩醛的简单有效的脱保护。该方法已有效地用于制备结合DNA的吡咯并[2,1- c ] [1,4]苯并二氮杂及其二聚体。
Chemoselective thioacetalization and transthioacetalization of carbonyl compounds catalyzed by immobilized scandium(III) triflate in ionic liquids
作者:Ahmed Kamal、Gagan Chouhan
DOI:10.1016/s0040-4039(03)00580-x
日期:2003.4
Immobilized scandium triflate [Sc(OTf)(3)] in ionic liquids has been found to be an extremely efficient and recyclable catalyst for the thioacetalization and transthioacetalization of both aromatic and aliphatic aldehydes. Significant rate acceleration and chemoselectivity was achieved by employing this catalytic system. (C) 2003 Elsevier Science Ltd. All rights reserved.
Simple, Mild and Efficient Thioacetalization and Transthioacetalization of Carbonyl Compounds and Deprotection of Thioacetals: Unique Role of Thiols in the Selectivity of Thioacetalization
Silicasupportedsodiumhydrogen sulfate (NaHSO 4 .SiO 2 ) has been employed for efficient thioacetalization and transthioacetalization of carbonyl compounds in CH 2 Cl 2 at room temperature. Selectivity of thioacetalization was dependent on the thiols used for the conversion. The same catalyst was also found to be effective for deprotection of thioacetals in CH 2 Cl 2 -H 2 O at room temperature.
Oxathioacetalization, thioacetalization and transthioacetalization of carbonyl compounds by N-bromosuccinimide: selectivity and scope
作者:Ahmed Kamal、Gagan Chouhan、Kaleem Ahmed
DOI:10.1016/s0040-4039(02)01610-6
日期:2002.9
Efficient oxathioacetalization, thioacetalization and transthioacetalization of carbonylcompounds have been achieved in high yields employing N-bromosuccinimide as a catalyst.