Pinacol Coupling Of Carbonyl Compounds Research Articles

Electrochemical formal homocoupling of sec-alcohols.

Electrochemical pinacol coupling of carbonyl compounds in an undivided cell with a sacrificial anode would be a promising approach toward synthetically valuable vic-1,2-diol scaffolds without using low-valent metal reductants. However, sacrificial anodes produce an equimolar amount of metal waste, which may be a major issue in terms of sustainable chemistry. Herein, we report a sacrificial anode-free electrochemical protocol for the synthesis of pinacol-type vic-1,2-diols from sec-alcohols, namely benzyl alcohol derivatives and ethyl lactate. The corresponding vic-1,2-diols are obtained in moderate to good yields, and good to high levels of stereoselectivity are observed for sec-benzyl alcohol derivatives. The present transformations smoothly proceed in a simple undivided cell under constant current conditions without the use of external chemical oxidants/reductants, and transition-metal catalysts.

ChemInform Abstract: Some Applications of Ultrasound Irradiation in Pinacol Coupling of Carbonyl Compounds

AbstractReview: 288 refs.

ChemInform Abstract: Effect of Fluoride Salts on Metal-Mediated Reactions. Aluminum/Fluoride Salt-Mediated Reduction and Pinacol Coupling of Carbonyl Compounds in Aqueous Media.

Metal fluoride salts were found to activate aluminum in water to react with carbonyl compounds to give the pinacol coupling products and/or the reduced alcohols. The metal ion of the fluoride salt was found to play a role in controlling the chemoselectivity and stereoselectivity of the reaction.

ChemInform Abstract: First Examples of Gold Nanoparticles Catalyzed Silane Alcoholysis and Silylative Pinacol Coupling of Carbonyl Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

First examples of gold nanoparticles catalyzed silane alcoholysis and silylative pinacol coupling of carbonyl compounds

In this Letter, we illustrate the first catalytic application of supported Au nanoparticles in silane alcoholysis. The reaction proceeds with low amount of catalysts, under solvent free conditions for liquid substrates, without additional ligands and in a very selective way for primary alcohols in the examined cases. Additionally, a gold catalyzed silylative pinacol coupling of carbonyl compound is observed for the first time and some hypotheses about the reaction mechanism are given.

Pinacol Coupling of Carbonyl Compounds by Using Al—NaOH/MeOH under Microwave Irradiation.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Novel and Efficient Ni‐Mediated Pinacol Coupling of Carbonyl Compounds.

Abstract It was firstly found that the Rieke Ni generated in situ was able to promote the pinacol coupling of various carbonyls efficiently. Based on this information, another catalytically effective, cheaper and more convenient NiCl2(Cat.)/Mg/TMSCl system was designed and developed further successfully. The interesting single-electron transfer (SET) mechanisms for the coupling reactions were proposed. Additionally, the dl /meso diastereoselectivity and some additive effects were also explained in terms of the proposed mechanisms.

Novel and efficient Ni-mediated pinacol coupling of carbonyl compounds

It was firstly found that the Rieke Ni generated in situ was able to promote the pinacol coupling of various carbonyls efficiently. Based on this information, another catalytically effective, cheaper and more convenient NiCl 2(Cat.)/Mg/TMSCl system was designed and developed further successfully. The interesting single-electron transfer (SET) mechanisms for the coupling reactions were proposed. Additionally, the dl/ meso diastereoselectivity and some additive effects were also explained in terms of the proposed mechanisms.

Effect of fluoride salts on metal-mediated reactions. Aluminum/fluoride salt-mediated reduction and pinacol coupling of carbonyl compounds in aqueous media

[formula: see text] Metal fluoride salts were found to activate aluminum in water to react with carbonyl compounds to give the pinacol coupling products and/or the reduced alchohols. The metal ion of the fluoride salt was found to play a role in controlling the chemoselectivity and stereoselectivity of the reaction.

Samarium mediated pinacol coupling of carbonyl compounds in the presence of a catalytic amount of iodine under aqueous media

AbstractIn the presence of a catalytic amount of iodine, metallic samarium mediated pinacol coupling of carbonyl compounds has been carried out under saturated aqueous Nl&Cl‐THF conditions at mom temperature. It gives corresponding 1,2‐diols in god yields.

Stabilizing Effect of HMPA (Hexamethylphosphoric Triamide) on Vanadium−Carbon Bonds and Their Application to Carbon−Carbon Bond Formation Reactions

Allylation of carbonyl compounds with allyl halides mediated by a vanadium(II) complex in a mixed solvent system of THF and HMPA has been accomplished. The addition of HMPA stabilized a vanadium−carbon bond of an allyl vanadium species and prevented dimerization of allyl halides or pinacol coupling of carbonyl compounds. Other alkylations such as a benzylation of carbonyl compounds or a Reformatsky-type reaction could also be mediated by a low-valent vanadium(II) species and benzyl bromide or bromo acetate in a THF−HMPA solvent system. By isolation of the vanadium−HMPA complex, [V2Cl3(hmpa)6][ZnCl3(hmpa)] (HMPA = hexamethylphosphoric triamide), and clarification of its structure, it became clear that the coordination of bulky HMPA to vanadium centers played an important role in the carbon−carbon bond-forming reactions.

ChemInform Abstract: Trimethylsilyl Chloride‐Accelerated Reduction and Pinacol Coupling of Carbonyl Compounds by Means of Samarium Diiodide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Samarium Iodide‐Catalyzed Pinacol Coupling of Carbonyl Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Trimethylsilyl chloride-accelerated reduction and pinacol coupling of carbonyl compounds by means of samarium diiodide

T. Honda and M. Katoh, Chem. Commun., 1997, 369 DOI: 10.1039/A607774I

Samarium Iodide-Catalyzed Pinacol Coupling of Carbonyl Compounds

Samarium Iodide-Catalyzed Pinacol Coupling of Carbonyl Compounds

Preparation of Samarium(II) Triflate and It Mediated Grignard-type Reaction. In Situ Formation and Reaction of New Organosamarium Reagents

Abstract Samarium(II) triflate was readily prepared by the reaction of samarium(III) triflate with sec-butyllithium at room temperature in THF. Its reducing ability was examined by pinacol coupling of carbonyl compounds. Sm(OTf)2 mediated Grignard-type reaction in THF-HMPA effectively; alkylation and allylation of ketones or aldehydes by simple alkyl, allyl, and benzyl halides proceeded via organosamarium intermediates.