Deoxygenative Borylation of Secondary and Tertiary Alcohols
作者:Florian W. Friese、Armido Studer
DOI:10.1002/anie.201904028
日期:2019.7.8
Two different approaches for the deoxygenative radical borylation of secondary and tertiary alcohols are presented. These transformations either proceed through a metal‐free silyl‐radical‐mediated pathway or utilize visible‐light photoredox catalysis. Readily available xanthates or methyl oxalates are used as radical precursors. The reactions show broad substrate scope and high functional‐group tolerance
Trifluoromethyl ethers R-OCF3 are easily synthesized from the corresponding dithiocarbonates R-OCS2Me (R = aryl or primary alkyl) by a reagent system consisting of 70% HF/pyridine and an N-halo imide. When the reaction is applied to R-OCS2Me wherein R = secondary alkyl, tertiary alkyl, or benzylic group, fluorination leading to the corresponding alkyl fluorides R-F is achieved, whereas a combination
Potassium Fluoride on Alumina: A Convenient Synthesis of O-Alkyl Methyldithiocarbonates. Pyrolysis of O-Benzyl-S-Methyldithiocarbonates
作者:Didier Villemin、Messaoud Hachemi
DOI:10.1080/00397919608004557
日期:1996.7
Abstract Xanthates were easily prepared by adsorption of alcohol on KF-Al2O3 followed by treatment of carbon disulfide and iodomethane at room temperature. Pyrolysis of benzyl xanthate affords to a complex mixture of products. A radical process was proposed to explain the nature of products obtained.
Deoxygenation of Alcohols Employing Water as the Hydrogen Atom Source
作者:David A. Spiegel、Kenneth B. Wiberg、Laura N. Schacherer、Matthew R. Medeiros、John L. Wood
DOI:10.1021/ja052185l
日期:2005.9.1
Trialkylboranes (BMe3, BEt3, and BBu3) have been shown to mediate reductive deoxygenation reactions of O-alkyl-S-methyl dithiocarbonates (methyl xanthates) in which water or deuterium oxide functions as the source of hydrogen or deuterium. This method has proven versatile with regard to substrate scope and is capable of providing protio- or deuterioalkane products in high yields with excellent levels
三烷基硼烷(BMe3、BEt3 和 BBu3)已被证明可介导 O-烷基-S-甲基二硫代碳酸酯(甲基黄原酸盐)的还原脱氧反应,其中水或氧化氘充当氢或氘的来源。该方法在底物范围方面已被证明是通用的,并且能够以高产率提供具有优异 D 掺入水平的质子或氘代烷烃产品。从头算计算表明,三烷基硼烷-水复合物具有异常低的 OH 键解离能 (73 kcal/mol),并支持该过程的自由基链机制。总之,本报告为水和三烷基硼烷在理论和应用研究中具有广泛重要性的根本新颖和以前被忽视的反应模式提供了证据。
Observations on the reaction of xanthate esters with 4-methyl(difluoroiodo)benzene: a new method for the conversion of alcohols to alkyl fluorides
作者:Mark J. Koen、Frederic Le Guyader、William B. Motherwell
DOI:10.1039/c39950001241
日期:——
Treatment of a range of S-methyldithiocarbonates (xanthates) with 4-methyl(difluoroiodo)benzene gives the corresponding alkyl fluorides.