Carbon Multiple Bonds Research Articles

ChemInform Abstract: Facile Reduction of Dithiocarbonates Derived from Secondary Alcohols with n-Bu3SnH-Et3B and Synthesis of 2-Furanthiones and 2-Furanones by Intramolecular Addition of Alkoxythiocarbonyl Free Radicals to Acetylenic Linkages.

The reduction of dithiocarbonates or thiocarbonates by n-Bu3SnH–Et3B easily gives the corresponding hydrocarbons. The intermediate alkoxythiocarbonyl radical equivalents are trapped by properly located carbon–carbon multiple bonds. The dithiocarbonates derived from either homopropargylic or homoallylic alcohols produce tetrahydrofuranones upon treatment with n-Bu3SnH–Et3B. Application of this new method to the conversion of carbonyl compounds into olefins is also described.

ChemInform Abstract: Addition of ArSSAr to Carbon—Carbon Multiple Bonds Using Electrochemistry.

AbstractThe electrochemical oxidation of diaryl sulfides such as (II) or (XII) generates arylbis(arylthio)sulfonium ions that react with alkenes to give — after quenching with a soft nucleophile and/or complete quenching with NEt3 — a series of di(arylthio) substituted compounds in a stereospecific and anti‐selective manner.

Addition of Metal Enolate Derivatives to Unactivated Carbon−Carbon Multiple Bonds

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTAddition of Metal Enolate Derivatives to Unactivated Carbon−Carbon Multiple BondsFabrice Dénès*†, Alejandro Pérez-Luna‡, and Fabrice Chemla*‡View Author Information CEISAM, UMR CNRS 6230, Université de Nantes, France, and IPCM, UMR CNRS 7201, UPMC Univ Paris 06, France* Corresponding authors: [email protected] and [email protected]†Université de Nantes, Laboratoire Chimie Et Interdisciplinarité: Synthèse, Analyse, Modélisation (CEISAM), UMR 6230, UFR des Sciences et des Techniques - 2, rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France. Tel.: +33(0)2 51 12 54 10. Fax: +33(0)2 51 12 54 02. E-mail: [email protected]‡UPMC Univ Paris 06, UMR 7201, Institut Parisien de Chimie Moléculaire (FR 2769), case courrier 183, 4 place Jussieu, F-75005 Paris, France. Tel.: +33 (0)1 44 27 64 36. Fax: +33 (0)44 27 75 67. E-mail: [email protected]Cite this: Chem. Rev. 2010, 110, 4, 2366–2447Publication Date (Web):March 2, 2010Publication History Received24 June 2008Published online2 March 2010Published inissue 14 April 2010https://doi.org/10.1021/cr800420xCopyright © 2010 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views10230Altmetric-Citations244LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (3 MB) Get e-AlertsSUBJECTS:Addition reactions,Anions,Cyclization,Hydrocarbons,Reaction products Get e-Alerts

Addition of ArSSAr to carbon–carbon multiple bonds using electrochemistry

ArS(ArSSAr) + (arylbis(arylthio)sulfonium ions), which were generated and accumulated by the electrochemical oxidation of diaryl disulfides (ArSSAr) in CH 2Cl 2 at −78 °C, reacted with alkenes to give the corresponding diarylthio-substituted compounds in a stereospecific manner in good yields, when the reaction was quenched with a soft nucleophile, such as allylsilanes, ketene silyl acetals, and triethylamine. A mechanism involving the initial formation of an episulfonium ion followed by ring-opening by the attack of ArSSAr has been suggested. The reactions of ArS(ArSSAr) + with alkynes also took place to give 1,2-diorganothio-substitued alkenes stereoselectively under similar conditions.

ChemInform Abstract: Metal‐Organic Frameworks (MOFs) as Heterogeneous Catalysts for the Chemoselective Reduction of Carbon—Carbon Multiple Bonds with Hydrazine.

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.

Silicon‐ and Tin‐Based Cuprates: Now Catalytic in Copper!

Silicon- and tin-containing molecules are versatile building blocks in organic synthesis. A stalwart method for their preparation relies on the stoichiometric use of silicon- and tin-based cuprates, although a few copper(I)-catalyzed or even copper-free protocols have been known for decades. In this Concept, we describe our efforts towards copper(I)-catalyzed carbon--silicon and also carbon--tin bond formations using soft bis(triorganosilyl) and bis(triorganostannyl) zinc reagents as powerful sources of nucleophilic silicon and tin. Conjugate addition, allylic substitution, and carbon--carbon multiple bond functionalization is now catalytic in copper!

Thiofluorination of Carbon–Carbon Multiple Bonds Using Electrochemically Generated ArS(ArSSAr)+BF4−

Abstract The reaction of alkenes and alkynes with ArS(ArSSAr)+BF4−, which was generated and accumulated by the low-temperature anodic oxidation of ArSSAr in Bu4NBF4/CH2Cl2, led to the addition of an ArS group and fluoride across the carbon–carbon multiple bond to give thiofluorinated compounds in good yields.

Reduction of Solid-Supported Olefins and Alkynes

The reduction of carbon-carbon multiple bonds in alkynes and olefins supported on a polystyrene resin has been investigated. Homogeneous catalysis by titanocene reagents is effective for the stereoselective preparation of cis-olefins from diarylacetylenes, while the use of copper(I) hydride reagents is effective for the reduction of alpha,beta-unsaturated ketones.

Now U=C it

A terminal uranium–carbon multiple bond has long been sought-after in actinide chemistry. Now, a complex featuring a dianionic carbon atom as part of a multidentate ligand brings actinide carbenes a little nearer.

Synthesis of condensed sulfur- and nitrogen-containing heterocycles via polar cycloaddition of hetarene sulfenyl chlorides to a C–C multiple bond

The reactions of HetSCl, where Het = 4,6-dimethyl-2-pyrimidyl, 3-methoxycarbonyl-2-pyridyl, 1,3-benzothiazol-2-yl and 8-quinolyl, with a carbon–carbon multiple bond in the LiClO4–MeNO2 system lead to the formation of products of polar cycloaddition of sulfur-containing electrophile with ring closure by the nitrogen atom of the HetS fragment.

Synthesis and Structural Characterization of Stable Organogold(I) Compounds. Evidence for the Mechanism of Gold-Catalyzed Cyclizations

The vast majority of homogeneous Au-catalyzed reactions have exploited the propensity of Au to activate unsaturated carbon-carbon bonds as electrophiles. It is generally assumed that a nucleophile attacks a gold-activated carbon-carbon multiple bond to give an alkenyl Au intermediate, notwithstanding the fact that these intermediates are hitherto unknown. We have obtained room temperature stable gamma-lactone gold(I) complexes through the reaction of cationic Au(I) reagents with allenoates, under mild conditions. The reactions of one such complex with electrophiles yielded the expected products of Au-catalyzed cyclizations. These results furnish experimental evidence for the mechanism of Au-catalyzed cyclizations.

A Catalytic Cycle for Oxidation of tert-Butyl Methyl Ether by a Double C−H Activation-Group Transfer Process

A square-planar, iridium(I) carbene complex is shown to effect atom and group transfer from nitrous oxide and organic azides, releasing the corresponding formate or formimidate and an iridium(I)−dinitrogen adduct. The dinitrogen complex performs C−H activation upon photolysis or thermolysis, regenerating the carbene from tert-butyl methyl ether with loss of H2. Taken together, these reactions represent a net catalytic cycle for C−H functionalization by double C−H activation to generate metal−carbon multiple bonds. Additionally, the unusual group transfer from diazo reagents underscores the unique nature of the reactivity observed for nucleophilic-at-metal carbene complexes.

ChemInform Abstract: Indium(III) Chloride Catalyzed Oxidative Cleavage of Carbon—Carbon Multiple Bonds by tert‐Butyl Hydroperoxide in Water — A Safe Alternative to Ozonolysis.

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.

Synthesis and Reactivity of Silylformylation Products Derived from Alkynes

AbstractThe silylformylation reaction of unsaturated compounds consists of the rhodium‐catalysed addition of a R3Si and a CHO moiety to a carbon–carbon multiple bond. The silylformylation process is applicable to both terminal and internal alkynes and is tolerant towards several functional groups. Many factors can influence the chemoselectivity of the reaction that generally affords β‐silylalkenals with high yields and regioselectivity. The β‐silylalkenals are polyfunctionalised substrates that can be submitted to several chemical transformations and in particular can undergo fluoride‐promoted (TBAF) aryl migration from an aryldimethylsilyl group to the adjacent carbon atom thus generating 2‐(arylmethyl)aldehydes, important industrial precursors of perfumes. This silylformylation‐aryl migration two‐steps sequence can be applied to functionalised alkyne precursors and chemo‐, regio‐ and stereoselectivity of the products can be modulated according to the nature and the position of the functional group. When a good leaving group is present in the ω position of the aliphatic chain of the alkyne cyclisation products are obtained, while α,β‐unsaturated aldehydes are generated from propargyl tosylamides, acetates and benzoates. α‐Silylmethylene‐β‐lactams, prepared from p‐tosylamides according to silylcarbocyclisation reaction, can be transformed into the corresponding arylmethyl‐β‐lactams by means of TBAF‐induced rearrangement that takes place without involving the lactam ring. A plausible mechanism of the rearrangement reaction is reported that suggests the addition of the fluoride ion to the arylsilicon moiety and the consequent migration of the aryl group to the adjacent carbon atom. Both aryl and heteroaryl substituents can migrate without any loss of configuration further enhancing the high synthetic value of this protocol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Synthesis and structural characterization of isolable phosphine coinage metal π-complexes

The chemical community has recently witnessed a dramatic increase in the application of cationic gold(I)-phosphine complexes as homogeneous catalysts for organic synthesis. The majority of gold(I)-catalyzed reactions rely on nucleophilic additions to carbon–carbon multiple bonds, which have been activated by coordination to a cationic gold(I) catalyst. However, structural evidence for coordination of cationic gold(I) complexes to alkynes has been limited. Here, we report the crystal structure of a gold(I)-phosphine η 2 -coordinated alkyne. Related Ag(I) and Cu(I) complexes have been synthesized for comparison. The crystallization of these complexes was enabled by tethering a labile alkyne ligand to a strongly coordinating triarylphosphine. This approach also proved applicable to crystallization of the first gold(I)-phosphine η 2 -coordinated alkene.

Indium(III) chloride-catalyzed oxidative cleavage of carbon–carbon multiple bonds by tert-butyl hydroperoxide in water—a safer alternative to ozonolysis

An efficient and general method for the oxidative cleavage of alkenes and alkynes using tert-butyl hydroperoxide and indium(III) chloride as catalyst in water to give the corresponding carboxylic acids or ketones has been achieved. The reaction conditions are compatible with sensitive moieties such as peptide bonds, tert-butyl carboxylic esters and N-Boc-protected tryptophan. The catalyst could be recycled.

Polyborylated reagents for modern organic synthesis.

Diverse kinds of gem- and vic-diborylated compounds are now readily available thanks to advances in gem-diborylation of lithium carbenoids as well as vic-diborylation of carbon–carbon multiple bonds with diboron compounds. These diborylated reagents lead to invention of polyborylated reagents and many novel and useful synthetic methods for supreme stereocontrol. This review summarizes preparative methods and synthetic reactions of di- and polyborylated reagents with the emphasis on multiple bond formation.

Asymmetric hydroamination of non-activated carbon–carbon multiple bonds

The catalysed enantioselective formation of carbon-nitrogen bonds by the hydroamination reaction is reviewed. All examples deal with substrates containing non-activated carbon-carbon multiple bonds which are transformed either via intramolecular or intermolecular reactions. Structurally different complexes already provided nitrogen containing compounds/heterocycles with high enantioselectivities.

Highly Selective Hydrogenation of Carbon–Carbon Multiple Bonds Catalyzed by the Cation [(C6Me6)2Ru2(PPh2)H2]+: Molecular Structure of [(C6Me6)2Ru2(PPh2)(CHCHPh)H]+, a Possible Intermediate in the Case of Phenylacetylene Hydrogenation

The dinuclear cation [(C(6)Me(6))(2)Ru(2)(PPh(2))H(2)](+) (1) has been studied as the catalyst for the hydrogenation of carbon-carbon double and triple bonds. In particular, [1][BF(4)] turned out to be a highly selective hydrogenation catalyst for olefin functions in molecules also containing reducible carbonyl functions, such as acrolein, carvone, and methyljasmonate. The hypothesis of molecular catalysis by dinuclear ruthenium complexes is supported by catalyst-poisoning experiments, the absence of an induction period in the kinetics of cyclohexene hydrogenation, and the isolation and single-crystal X-ray structure analysis of the tetrafluoroborate salt of the cation [(C(6)Me(6))(2)Ru(2)(PPh(2))(CHCHPh)H](+) (2), which can be considered as an intermediate in the case of phenylacetylene hydrogenation. On the basis of these findings, a catalytic cycle is proposed which implies that substrate hydrogenation takes place at the intact diruthenium backbone, with the two ruthenium atoms acting cooperatively in the hydrogen-transfer process.

Cycloaddition of “N‐Acyliminium Ion Pools” with Carbon—Carbon Multiple Bonds.

AbstractFor Abstract see ChemInform Abstract in Full Text.