Aldehydes and ketones, on treatment with a low-valent cerium reagent, undergo reductive dimerization to produce the corresponding pinacols in high yield.
醛和酮经低价铈试剂处理后,进行还原二聚化,从而以高收率生产相应的频哪醇。
On-Column Solvent-Free Oxidative Cleavage Reactions of Vicinal Diols by Silica Gel and Paraperiodic Acid: Application to In-Situ Sequential Oxidation and Knoevenagel Reactions
作者:Saada C. Dakdouki、Didier Villemin、Nathalie Bar
DOI:10.1002/ejoc.201101329
日期:2012.2
An on-column solvent-free oxidativecleavagereaction of vicinaldiols by paraperiodic acid supported on silica gel at room temperature is described. The resulting pure carbonyl compounds are prepared in good to excellent yields with short reaction times. The cleavagereactions proceed under mild conditions, which avoids further cyclization reactions of the product dialdehydes. This method is also
Studies on the Lanthanum‐Induced Pinacol Coupling of Aromatic Aldehydes and Ketones in Aqueous Media
作者:Yan‐Jiang Bian、Xu‐Guang Yu、Hong‐Wei Peng、Ji‐Tai Li
DOI:10.1080/00397910600781307
日期:2006.8.1
Abstract The pinacol coupling of aromaticaldehydes and ketones was carried out in 16–71% yield using La–36%HAc–CH2Cl2 system with stirring at rt in 4 h. The reactions in the same system gave pinacols in 12–91% yield under ultrasound irradiation at rt in 2 h.
An Original On-Column Oxidative Cleavage of Vicinal Diols Using Alumina/Potassium Periodate: Application to Sequential Oxidation/Horner-Emmons Reactions
作者:Saada C. Dakdouki、Didier Villemin、Nathalie Bar
DOI:10.1002/ejoc.201100396
日期:2011.8
unprecedented simple on-column solvent-free oxidativecleavage of vicinaldiols in the solid phase usingalumina/ potassium metaperiodate is described herein. It permits preparation of the corresponding carbonyl compounds with high purity and good to excellent yields requiring only short reaction times. This methodology is then employed in on-columnsequentialoxidation/Horner―Emmons reactions for the preparation
pinacol-type couplings between two structurally similar aromatic aldehydes promoted by low-valenttitanium generated unsymmetrical pinacols in moderate to good isolated yields in an erythro/threo ratio of up to 91:9. This synthetic methodology significantly extends the scope of the cross pinacol-type couplings. pinacol - pinacol-type coupling - cross coupling - McMurry coupling - low-valenttitanium