Reduction of alkyl and vinyl sulfonates using the CuCl2·2H2O–Li–DTBB(cat.) system
摘要:
The reduction of a series of alkyl mesylates, dimesylates and triflates to the corresponding hydrocarbons was efficiently performed using a reducing system composed of CuCl2 center dot 2H(2)O, an excess of lithium sand and a catalytic amount (5 mol%) of 4,4'-di-tertbutylbiphenyl (DTBB), in tetrahydrofuran at room temperature. The process was also applied to enol and dienol triflates affording alkenes and dienes, respectively. The use of the deuterated copper salt CuCl2 center dot 2D(2)O allowed the simple preparation of the corresponding deuterated products. (c) 2005 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Reduction of Alkyl Triflates and Iodides: An Efficient Method for the Deoxygenation of Primary and Secondary Alcohols
作者:Hester Dang、Nick Cox、Gojko Lalic
DOI:10.1002/anie.201307697
日期:2014.1.13
We describe an effective method for catalytic reduction of 1° alkyl sulfonates, and 1° and 2° iodides in the presence of a wide range of functional groups. This Cu‐catalyzed reaction provides a means for the effective deoxygenation of alcohols, as demonstrated by the highly selective reduction of 1° alcohols using a triflation/reduction sequence. A preliminary study of the reaction mechanism suggests
Two-Phase Oxidations with Aqueous Hydrogen Peroxide Catalyzed by Amphiphilic Pyridinium and Diazinium Salts
作者:Tomáš Hartman、Jiří Šturala、Radek Cibulka
DOI:10.1002/adsc.201500687
日期:2015.11.16
Amphiphilic pyridinium and diazinium salts were shown to be effective catalysts in two-phase (water/chloroform or water/dichloromethane) sulfoxidations and N-oxidations with hydrogenperoxide under mild conditions. This unprecedented oxidation method utilizes covalent bonding of hydrogenperoxide to a simple pyridinium or diazinium nucleus to increase the lipophilicity of the hydroperoxide species
Synthesis of Ethers via Reaction of Carbanions and Monoperoxyacetals
作者:ShivaKumar Kyasa、Rebecca N. Meier、Ruth A. Pardini、Tristan K. Truttmann、Keith T. Kuwata、Patrick H. Dussault
DOI:10.1021/acs.joc.5b02043
日期:2015.12.18
organolithium and organomagnesium reagents to furnish moderate to high yields of ethers. The method is successfully applied to the synthesis of alkyl, alkenyl, aryl, heteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters. In contrast to reactions of dialkyl and alkyl/silyl peroxides, the displacements of monoperoxyacetals provide no evidence for alkoxy radical intermediates. At the
尽管亲电烷氧基(“ RO +”)从有机过氧化物转移至有机金属化合物为传统的醚化方法提供了补充,但其应用受到与过氧化物反应性和稳定性相关的限制。现在我们证明容易制备的四氢吡喃基单过氧缩醛与sp 3和sp 2有机锂和有机镁试剂反应,以提供中等至高产率的醚。该方法已成功应用于烷基,烯基,芳基,杂芳基和环丙基醚,混合的O,O-乙缩醛和S,S,O的合成-原酸酯。与二烷基和烷基/甲硅烷基过氧化物的反应相反,单过氧缩醛的取代没有提供烷氧基自由基中间体的证据。同时,对于伯,仲或叔醇盐的转移,观察到的高产率,后者涉及对新戊基氧的攻击,与S N 2机制不一致。理论研究表明,涉及路易斯酸的机理促进了有机金属插入O-O键中。
Electrophilic Etherification of α-Heteroaryl Carbanions with Monoperoxyacetals as a Route to Ketene <i>O</i>,<i>O</i>- and <i>N</i>,<i>O</i>-Acetals
作者:Timothy J. Paris、Chris Schwartz、Rachel Willand-Charnley
DOI:10.1021/acs.joc.0c02506
日期:2021.2.5
electrophilic oxygen. Heteroaryl ketene acetals are remarkably stable throughout traditional purification techniques; the superior stability of ketene N,O-acetals compared to ketene O,O-acetals is presumably due to increased aromaticity of the indole and pyridine structures. The presented method overcomes typical problems associated with alkyl ketene acetal synthesis as reported products withstood workup
Sweet surfactants: packing parameter-invariant amphiphiles as emulsifiers and capping agents for morphology control of inorganic particles
作者:Michael Voggel、Rebecca M. Meinusch、Vanessa Siewert、Marius Kunkel、Valentin Wittmann、Sebastian Polarz
DOI:10.1039/c8sm01091a
日期:——
Exploration of isomer effects on amphiphile properties (e.g.emulsification and as nanoparticle growth modifiers) using a library of glycoside-based surfactants.