Perchloric Acid Impregnated on Silica Gel (HClO4/SiO2): A Versatile Catalyst for Michael Addition of Thiols to the Electron-Deficient Alkenes
作者:Abu T. Khan、Subrata Ghosh、Lokman H. Choudhury
DOI:10.1002/ejoc.200600006
日期:2006.5
Perchloricacid adsorbed on silica gel (HClO4/SiO2) has been found to be a highly efficient and versatile catalyst for the Michael addition of thiols to a wide variety of conjugated alkenes such as α,β-unsaturated ketones, carboxylic esters, nitriles, amides and chalcones in dichloromethane or methanol at room temperature. The reactions are completed within 2–20 min in high yields. Some of the additional
Asymmetric syntheses based on 1,3-oxathianes. 2. Synthesis of chiral tertiary .alpha.-hydroxy aldehydes, .alpha.-hydroxy acids, glycols [R1R2C(OH)CH2OH], and carbinols [R1R2C(OH)Me] in high enantiomeric purity.
作者:Joseph E. Lynch、Ernest L. Eliel
DOI:10.1021/ja00322a034
日期:1984.5
Scission par le N-chlorosuccinimide de trimethyl-4,4,7 oxa-1thia-3 bicyclo [4.4.0] decanecarbinols, avec formation d'α-aldols. Etude de l'oxydation et de la reduction de ces α-aldols
Scission par le N-chlorosuccinimide de trimethyl-4,4,7 oxa-1thia-3 双环 [4.4.0] 癸烷醇,avec 形成 d'α-醛醇。α-醛醇的氧化和还原练习曲
New reagent for the optical resolution of ketones: (−) (1R, 2R, 5R)-5-methyl-2-(1-mercapto-1-methylethy)-cyclohexanol. Application to trans dimethyl cyclopentanone-3,4-dicarboxylate.
作者:Guy Solladié、Olivier Lohse
DOI:10.1016/s0957-4166(00)80357-2
日期:1993.7
(-) (1R, 2R, 5R)-5-methyl-2-(1-mercapto-1-methylethyl)-cyclohexanol was shown to be a very powerful agent for the optical resolution of ketones. It was used for the resolution of trans dimethyl cyclopentanone-3,4-dicarboxylate combined with the epimerization of the more soluble diastereomer, allowing an efficient second order asymmetric transformation to give the (SS) enantiomer in 80% yield.