Reaction of Cp2(CH3)Ta=CH2 with Ru3(CO)12: deoxygenative coupling of carbon monoxide and methylene units to give a heteronuclear cluster-bound 4-cumulene ligand

1995 ◽  
Vol 73 (7) ◽  
pp. 1111-1115 ◽  
Author(s):  
Grant Proulx ◽  
Frederick J. Hollander ◽  
Robert G. Bergman
Keyword(s):  
Carbon Monoxide ◽  
Metal Carbonyl ◽  
Cluster Complex ◽  
Metal Centers ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Late Transition ◽  
Heteronuclear Cluster ◽  
Mechanisms Of Reactions ◽  
Carbonyl Species

The mechanisms of reactions that deoxygenate carbon monoxide (CO) and convert it into longer-chain hydrocarbons are not well understood. A reaction is reported between an early metal methylidene complex and a late transition metal carbonyl species that results in CO deoxygenation along with coupling of the CO carbon to methylidene groups and other CO carbons. The Schrock tantalum-methylene complex (η5-C5H5)Ta(=CH2)(CH3) reacts with the trinuclear metal carbonyl species Ru3(CO)12 to yield the cluster complex Cp2(CH3)Ta(µ-O)Ru3(C4H4)(CO)9. This material contains a 4-cumulene ligand that bridges the three late-metal centers. Also formed in this reaction is the unstable free tantalum oxo species, (η5-C5H5)Ta(=O)(CH3). A crystal structure of the TaRu3 cluster is reported along with a proposed mechanism for this unusual carbon–carbon bond-forming reaction. Keywords: deoxygenation, carbon monoxide, alkylidene, coupling, cluster.

Reaction of a Tantalum Alkylidene Complex with Dinuclear Metal Carbonyls: Formation of C3 ligands

Science ◽  
1993 ◽  
Vol 259 (5095) ◽  
pp. 661-663 ◽  
Author(s):  
Grant Proulx ◽  
Robert G. Bergman
Keyword(s):  
Homogeneous Solution ◽  
Coupling Reactions ◽  
The Novel ◽  
Metal Carbonyls ◽  
Metal Centers ◽  
Bond Forming ◽  
Isotope Tracer ◽  
Carbon Carbon Bond ◽  
Late Transition ◽  
Co Coupling

The mechanisms of reactions that deoxygenate carbon monoxide (CO) and convert it into longer chain hydrocarbons are not well understood. A series of reactions between "early" and "late" transition metal complexes that result in CO coupling reactions in a homogeneous solution are reported. In one example, the Schrock tantalum-methylene complex (η5-C5H2)2Ta(CH2)(CH3) reacts with the dinuclear metal carbonyls CO2(CO)8 and Fe2(CO)9 in a novel fashion to yield a C3H2O2 ligand bridging three metal centers. Reaction of the tantalum-methylene complex with Re2(CO)10 leads to an even more substantial change in which extensive rearrangement along with three-carbon coupling occurs. An oxygen atom is removed from one CO group, leading to the novel oxotantalum compound (η5-C5H5)2(CH3)Ta=O. Simultaneously, the carbon atom from the transformed CO couples with two CH2 groups initially bound to tantalum and the CH2 hydrogens are rearranged to produce a CH3-CC ligand. Low-temperature nuclear magnetic resonance and isotope tracer experiments have provided preliminary information about the mechanisms of these unusual carbon-carbon bond-forming reactions.

Carbon-carbon bond-forming reactions of cobaltacyclopentene/cobaltaoxanorbornadiene complexes with isocyanides, carbon monoxide, and alkynes

1988 ◽  
Vol 7 (5) ◽  
pp. 1073-1083 ◽  
Author(s):  
Maryrose. Scozzafava ◽  
Alan M. Stolzenberg
Keyword(s):  
Carbon Monoxide ◽  
Carbon Bond ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Bond Forming Reactions

New carbon-carbon bond-forming reaction of carbon monoxide: remarkable trialkylation of a carbonyl ligand in a molybdenum pentadienyl complex

1985 ◽  
Vol 107 (26) ◽  
pp. 8296-8297 ◽  
Author(s):  
Michael S. Kralik ◽  
John P. Hutchinson ◽  
Richard D. Ernst
Keyword(s):  
Carbon Monoxide ◽  
Carbonyl Ligand ◽  
Carbon Bond ◽  
Bond Forming ◽  
Carbon Carbon Bond

Visible-Light Photosensitized Aryl and Alkyl Decarboxylative Carbon-Heteroatom and Carbon-Carbon Bond Formations

2019 ◽  
Author(s):  
Tuhin Patra ◽  
Satobhisha Mukherjee ◽  
Jiajia Ma ◽  
Felix Strieth-Kalthoff ◽  
Frank Glorius
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Alkyl Radical ◽  
General Strategy ◽  
Alkyl Radicals ◽  
Bond Forming ◽  
Radical Trapping ◽  
Carbon Carbon Bond ◽  
Radical Generation ◽  
Trapping Agent

<sub>A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.</sub>

Acetylene Radical-Cations in Carbon-Carbon Bond Forming Reactio ns

2017 ◽  
Vol 14 (3) ◽  
Author(s):  
Aleksander V. Vasilyev
Keyword(s):  
Radical Cations ◽  
Carbon Bond ◽  
Bond Forming ◽  
Carbon Carbon Bond

Microwave-accelerated Carbon-carbon and Carbon-heteroatom Bond Formation via Multi-component Reactions: A Brief Overview

2020 ◽  
Vol 7 (1) ◽  
pp. 23-39 ◽  
Author(s):  
Kantharaju Kamanna ◽  
Santosh Y. Khatavi
Keyword(s):  
Organic Synthesis ◽  
Bond Formation ◽  
Cycloaddition Reaction ◽  
Nanoparticle Synthesis ◽  
Single Step ◽  
Bioactive Molecules ◽  
One Pot ◽  
Bond Forming ◽  
Material Interest ◽  
Carbon Carbon Bond

Multi-Component Reactions (MCRs) have emerged as an excellent tool in organic chemistry for the synthesis of various bioactive molecules. Among these, one-pot MCRs are included, in which organic reactants react with domino in a single-step process. This has become an alternative platform for the organic chemists, because of their simple operation, less purification methods, no side product and faster reaction time. One of the important applications of the MCRs can be drawn in carbon- carbon (C-C) and carbon-heteroatom (C-X; X = N, O, S) bond formation, which is extensively used by the organic chemists to generate bioactive or useful material synthesis. Some of the key carbon- carbon bond forming reactions are Grignard, Wittig, Enolate alkylation, Aldol, Claisen condensation, Michael and more organic reactions. Alternatively, carbon-heteroatoms containing C-N, C-O, and C-S bond are also found more important and present in various heterocyclic compounds, which are of biological, pharmaceutical, and material interest. Thus, there is a clear scope for the discovery and development of cleaner reaction, faster reaction rate, atom economy and efficient one-pot synthesis for sustainable production of diverse and structurally complex organic molecules. Reactions that required hours to run completely in a conventional method can now be carried out within minutes. Thus, the application of microwave (MW) radiation in organic synthesis has become more promising considerable amount in resource-friendly and eco-friendly processes. The technique of microwaveassisted organic synthesis (MAOS) has successfully been employed in various material syntheses, such as transition metal-catalyzed cross-coupling, dipolar cycloaddition reaction, biomolecule synthesis, polymer formation, and the nanoparticle synthesis. The application of the microwave-technique in carbon-carbon and carbon-heteroatom bond formations via MCRs with major reported literature examples are discussed in this review.

scholarly journals Front Cover: Reductive Carbon–Carbon Bond Forming Reactions with Carbonyls Mediated by Rh–H Complexes (Eur. J. Org. Chem. 42/2020)

2020 ◽  
Vol 2020 (42) ◽  
pp. 6501-6501
Author(s):  
Kazuyuki Sato ◽  
Motoyuki Isoda ◽  
Atsushi Tarui ◽  
Masaaki Omote
Keyword(s):  
Carbon Bond ◽  
Front Cover ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Bond Forming Reactions
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