Carbon-carbon Bond Cleavage Reactions Research Articles

遷移金属を用いた炭素−炭素結合切断とその応用

Carbon-carbon bond cleavage reactions of organic compounds using transition metal complexes are reviewed. The reactions are first classified by the bond order; (i) carbon-carbon single bond cleavage, (ii) carbon-carbon double bond cleavage, and (iii) carbon-carbon triple bond cleavage. For the carbon-carbon single bond cleavage reactions, reactions are classified by the functional groups of the organic compounds. It is shown that in many cases the β, γ-carbon-carbon bond of the organic molecules on metals tends to be cleaved formally. In the case of the carbon-carbon double bond, there are only some examples of the direct cleavage by metals such as a ketene which produces a carbonyl-carbene complex. The direct cleavage of the double bond by metals, which formally affords bis-carbene, is not favorable. In contrast, the carbon-carbon cleavage of the triple bond is achieved by the multi-metal systems which stabilize the cleaved fragments.

The structure of L-ribulose-5-phosphate 4-epimerase: an aldolase-like platform for epimerization.

The structure of L-ribulose-5-phosphate 4-epimerase from E. coli has been solved to 2.4 A resolution using X-ray diffraction data. The structure is homo-tetrameric and displays C(4) symmetry. Each subunit has a single domain comprised of a central beta-sheet flanked on either side by layers of alpha-helices. The active site is identified by the position of the catalytic zinc residue and is located at the interface between two adjacent subunits. A remarkable feature of the structure is that it shows a very close resemblance to that of L-fuculose-1-phosphate aldolase. This is consistent with the notion that both enzymes belong to a superfamily of epimerases/aldolases that catalyze carbon-carbon bond cleavage reactions via a metal-stabilized enolate intermediate. Detailed inspection of the epimerase structure, however, indicates that despite the close overall structural similarity to class II aldolases, the enzyme has evolved distinct active site features that promote its particular chemistry.

Autoxidation of 4-amorphen-11-ol and the biogenesis of nor- and seco-amorphane sesquiterpenes from fabiana imbricata

Photooxidation of 4-amorphen-11-ol ( 1), recently reported as one of the major sesquiterpene natural products from the medicinal plant Fabiana imbricata, results in three allylic hydroperoxides 6, 9 and 10, which are expected from the “ene-type” reaction of molecular oxygen with the tri-substituted double bond in 1. The tertiary allylic hydroperoxide 6 undergoes carbon-carbon bond cleavage and a second autoxidation reaction to yield the more highly oxygenated seco-amorphane 11 under very mild conditions. In acid, this compound may then undergo either a second carbon-carbon bond cleavage reaction to yield nor-sesquiterpenes 2 and 3 (reported as bona fide natural products from F. imbricata, or cyclize to the sesquiterpene peroxofabianane ( 5), which is a presumed precursor to the natural product fabianane ( 4). Some mechanistic investigations concerning the two chemical processes: viz:- carbon-carbon bond cleavage and autoxidation which would account for the formation of natural products 2, 3 and 4 from 1 are reported. Tertiary allylic hydroperoxide 32, which lacks the 11-hydroxyl functional group present in 1 undergoes only C-4/C-5 carbon-carbon bond cleavage under more forcing conditions, suggesting a role for this functional group in assisting the autoxidation reactions of 4-amorphen-11-ol.

Enantiospecific Synthesis of (+)-Nemorensic Acid, a Necic Acid Component of the Macropyrrolizidine Alkaloid, Nemorensine.

A concise enantiospecific synthesis of nemorensic acid 3, a necic acid component of the macropyrrolizidine alkaloid nemorensine 2, isolated from Senecio nemorensis L., is described. Reaction of an epsilon-halo-alpha,beta-unsaturated ester (8), readily accessible from a monoterpene (-)-carvone, with samarium iodide gave a fragmentation product (9), where a carbon-carbon bond cleavage reaction occurred between the gamma and delta positions of the carbonyl group, regioselectively. Deprotection of the silyl group of 9 brought about an intramolecular cyclization to provide tetrahydrofuran derivatives (10), which, upon chemical modification of the side chain, gave nemorensic acid.

Allohimachalane, seco-allohimachalane and himachalane sesquiterpenes from Illicium tsangii

The dichloromethane extract of I. tsangii has yielded ten novel sesquiterpenes ( 1–4, 6–11) possessing or derived from the very rare allohimachalane skeleton, in addition to one new himachalane ( 12) and a new megastigmane ( 14). It is suggested that the novel skeletons possesed by seco-allohimachalanes 8–11 are the result of carbon-carbon bond cleavage reactions associated with hydroperoxide autoxidation products (e.g. 6, 7) of the tri-substituted double bond.

A concise enantiospecific synthesis of (−)-invictolide

(−)-Invictolide, a component of the queen recognition pheromone of Solenopsis invicta, was stereoselectively synthesized starting from (−)-carvone, where the regioselective carbon-carbon bond cleavage reaction of γ-halo ester with samarium diiodide was successfully involved as an important reaction.

Carbon-carbon bond cleavage reactions of 1,2-diamines initiated by photoinduced electron transfer

The oxidative photofragmentations of a series of 1,2-diamines have been studied in reaction with photoexcited electron acceptors under a variety of conditions. All the diamines were found to undergo a clean two electron redox reaction (in the presence of trace amounts of water) to produce after cleavage, two free amines, two aldehydes, and the reduced acceptor. Investigation of the role of variables (solvent, acceptor, temperature, isotope effects, etc.) on the quantum yields for diamine fragmentation leads to a mechanistic picture in which the critical step in the reaction is an unassisted fragmentation. Although formally similar to the photoreactions of previously studied aminoalcohols, the photoinduced electron transfer fragmentation reaction of 1,2-diamines shows key mechanistic differences and is apparently both a more general reaction and significantly more rapid in several cases.

A Novel Oxygenative Carbon-Carbon Bond Cleavage Reaction by Irradiation of Alkylcobaloximes Having a Phenyl Group at the .beta.-Position

A Novel Oxygenative Carbon-Carbon Bond Cleavage Reaction by Irradiation of Alkylcobaloximes Having a Phenyl Group at the .beta.-Position

Novel carbon-carbon bond cleavage reaction of penem antibiotic by class C beta-lactamases.

Novel carbon-carbon bond cleavage reaction of penem antibiotic by class C beta-lactamases.

Purification and characterization of an enzyme involved in oxidative carbon-carbon bond cleavage reactions in the methionine salvage pathway of Klebsiella pneumoniae.

The 5-methylthio-D-ribose moiety of 5'-(methylthio)-adenosine is converted to methionine in a wide variety of organisms. 2,3-Diketo-5-methylthio-1-phosphopentane is an advanced intermediate in the methionine recycling pathway present in the Gram-negative bacterium Klebsiella pneumoniae. This unusual metabolite is oxidatively cleaved to yield formate (from C-1), 2-keto-4-methylthiobutyrate (the transamination product of methionine), and 3-methylthiopropionate. To further characterize this oxidative conversion, the desthio analog of the naturally occurring diketone, namely 2,3-diketo-1-phosphohexane I, was synthesized. If the metabolism of I is analogous to that of 2,3-diketo-5-methylthio-1-phosphopentane it should be converted to formate, 2-ketopentanoate, and butyrate. An enzyme (E-1), which mediates the oxidative conversion of I to formate and 2-ketopentanoate, was isolated from extracts of K. pneumoniae. E-1 was purified 100-fold to homogeneity in 10% yield. The native enzyme is a monomeric protein of M(r) 27,000. The activity of E-1 requires magnesium ion as a cofactor. No other prosthetic groups were detected. Incubation of the enzyme with I, under anaerobic conditions, led to the discovery of two intermediates. These species have been identified by 1H and 13C NMR, UV-visible spectroscopy, and model chemistry studies as 2-hydroxy-3-keto-1-phospho-1-hexene II, generated by enolization of I; and 1,2-dihydroxy-3-keto-1-hexene III, generated by enzymatic dephosphorylation of II. Intermediates II and III are released from the active site of the enzyme; III accumulates under anaerobic conditions. Under aerobic conditions, III is non-enzymically oxidized to 2-ketopentanoate, formate, and other products. Compound II was also generated by heating I at pH 7.5 for 7 min. Action of alkaline phosphatase on II produces III.

Pyrimidine Derivatives. XI. Facile Carbon-Carbon Bond-Cleavage Reaction of 6-Bromomethylpyrimidinediones and (2,4-Dioxo-1,2,3,4-tetrahydropyrimidin-6-yl)methyl Nitrate via 6-Formyl Derivatives.

Pyrimidine Derivatives. XI. Facile Carbon-Carbon Bond-Cleavage Reaction of 6-Bromomethylpyrimidinediones and (2,4-Dioxo-1,2,3,4-tetrahydropyrimidin-6-yl)methyl Nitrate via 6-Formyl Derivatives.

Concise enantiospecific syntheses of (+)-Eldanolide and (−)- cis-whisky lactone

(+)-Eldanolide 3 and (−)- cis-whisky lactone 6 were synthesized by employing a reductive carbon-carbon bond cleavage reaction of the cyclopentane derivative 1b, readily accessible from (+)-carvone, as a key step.

On the remarkable propensity for carbon-carbon bond cleavage reactions in the C(8)-C(10) region of FK-506

It has been deduced from a series of transformations that formation of a tetrahedral intermediate at C 9 in FK-506 occasions fragmentation of the C 9 -C 10 bond by a retro-Claisen-like pathway or the C 9 -C 8 bond by a benzilic acid type rearrangement. Reduction of FK-506 with L-Selectride leads to the formation of a boronate ester 18 rather than to the corresponding diol 17, which had previously been formulated. Direct reduction of FK-506 with sodium triacetoxyborohydride (or hydrolysis of 18) does provide access to (22S)-dihydro FK-506 17. The former reduction also leads to some 22R epimer, which is an intermediate in the total synthesis of FK-506

Conversion of 5-S-methyl-5-thio-D-ribose to methionine in Klebsiella pneumoniae. Stable isotope incorporation studies of the terminal enzymatic reactions in the pathway.

Extracts of Klebsiella pneumoniae convert 5-S-methyl-5-thio-D-ribose (methylthioribose) to methionine and formate. To probe the terminal steps of this biotransformation, [1-13C]methylthioribose has been synthesized and its metabolism examined. When supplemented with Mg2+, ATP, L-glutamine, and dioxygen, cell-free extracts of K. pneumoniae converted 50% of the [1-13C]methylthioribose to [13C]formate. The formation of [13C]formate was established by 13C and 1H NMR spectroscopy studies of the purified formate, and by 13C and 1H NMR spectroscopy and mass spectrometry studies of its p-phenylphenacyl derivative. By contrast, no incorporation of label from [1-13C]methylthioribose into the biosynthesized methionine was detected by either mass spectrometry or 13C and 1H NMR spectroscopy. The most reasonable interpretation of these results is that C-1 of methylthioribose is converted directly to formate concomitant with the conversion of carbon atoms 2-5 to methionine. The penultimate step in the conversion of methylthioribose to methionine and formate is an oxidative carbon-carbon bond cleavage reaction in which an equivalent of dioxygen is consumed. To investigate the fate of the dioxygen utilized in this reaction, the metabolism of [1-13C]methylthioribose in the presence of 18O2 was also examined. Mass spectrometry revealed the biosynthesis of substantial amounts of both [18O1]methionine and [13C, 18O1]formate under these conditions. These results suggest that the oxidative transformation in the conversion of methylthioribose to methionine and formate may be catalyzed by a novel intramolecular dioxygenase. A mechanism for this dioxygenase is proposed.

A carbon-carbon bond cleavage reaction of carbon suboxide at a metal center. Synthesis and structural characterization of WCl2(CO)(PMePh2)2{C,C':.eta.2-C(O)CPMePh2} [Erratum to document cited in CA109(9):73587a

A carbon-carbon bond cleavage reaction of carbon suboxide at a metal center. Synthesis and structural characterization of WCl2(CO)(PMePh2)2{C,C':.eta.2-C(O)CPMePh2} [Erratum to document cited in CA109(9):73587a

A carbon-carbon bond cleavage reaction of carbon suboxide at a metal center. Synthesis and structural characterization of WCl2(CO)(PMePh2)2{C,C':.eta.2-C(O)CPMePh2}

A carbon-carbon bond cleavage reaction of carbon suboxide at a metal center. Synthesis and structural characterization of WCl2(CO)(PMePh2)2{C,C':.eta.2-C(O)CPMePh2}

Crossed-beam studies of energy and angular distributions of organometallic reactions: decarbonylation of acetaldehyde by iron(I) and chromium(I)

The energetics and dynamics of the reactions of gas-phase transition-metal ions with organic molecules are topics of active research and speculation at present. In the present work, the authors report the first crossed-beam studies of gas-phase transition-metal ion chemistry, demonstrating that product kinetic energy and angular distributions probe the potential energy surface topology of simple carbon-carbon bond cleavage reactions. The studies yield information on the lifetimes and stabilities of key intermediates and assess the partitioning of energy in these species. The authors present results on the direct decarbonylation of acetaldehyde by Fe/sup +/ and Cr/sup +/.

Ion beam studies of the reactions of atomic cobalt ions with alkanes: determination of metal-hydrogen and metal-carbon bond energies and an examination of the mechanism by which transition metals cleave carbon-carbon bonds

An ion beam apparatus is employed to study the reactions of singly charged cobalt positive ions with hydrogen and 17 alkanes. Reaction cross sections and product distributions as a function of kinetic energy are determined. Exothermic carbon-carbon bond cleavage reactions are observed for all alkanes but methane and ethane. A mechanism involving oxidative addition of C-C and C-H bonds to cobalt as a first step is demonstrated to account for all major reactions at all energies. Interpretation of several endothermic processes allows the extraction of thermochemical data. The bond dissociation energies obtained are D/sup 0/(Co/sup +/-H) = 52 +- 4 kcal/mol, D/sup 0/(Co-H) = 39 +- 6 kcal/mol, D/sup 0/(Co/sup +/-CH/sub 3/) = 61 +- 4 kcal/mol, and D/sup 0/(Co-CH/sub 3/) = 41 +- 10 kcal/mol.

Carbon-carbon bond cleavage reactions in the decomposition of metallacycles

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-carbon bond cleavage reactions in the decomposition of metallacyclesRobert H. Grubbs and Akira MiyashitaCite this: J. Am. Chem. Soc. 1978, 100, 23, 7418–7420Publication Date (Print):November 1, 1978Publication History Published online1 May 2002Published inissue 1 November 1978https://doi.org/10.1021/ja00491a052RIGHTS & PERMISSIONSArticle Views602Altmetric-Citations56LEARN 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 PDF (358 KB) Get e-Alerts Get e-Alerts