Theoretical studies of transition metal complexes with nitriles and isocyanides

Kuznetsov, Maxim L.

doi:10.1070/rc2002v071n04abeh000708

Cited by 64 publications

(65 citation statements)

References 66 publications

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“…Probably, the decrease in the occupancy of the antibonding *(CN)-orbital causes the strengthening of the C N bond due to complex formation. This reflects in vibrational spectra as a high frequency shift of (C N) [50]. For nitrile complexes with transition metals, the -bonding may also be present in addition to the -donation, but the total contribution of nitrile -orbitals (both and *) to valence MO of the complex generally is insignificant and the -component dominates [50].…”

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 96%

“…For C N ligands, the interaction with transition metal results in -donation of the electron density from the occupied bonding -orbitals of nitrile ( 1 -and 2 -MO) to the vacant d-orbital of the metal ion [50]. Apart from these, interaction involves the third lower-energy -orbital of the nitrile, which is an antibonding with respect to the C N bond.…”

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 97%

“…This reflects in vibrational spectra as a high frequency shift of (C N) [50]. For nitrile complexes with transition metals, the -bonding may also be present in addition to the -donation, but the total contribution of nitrile -orbitals (both and *) to valence MO of the complex generally is insignificant and the -component dominates [50]. Since nitriles interact with the metal cation mainly by -bonding, the ligands can be coordinated with metal cations of any nature.…”

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

“…The second possibility -the -coordination of nitrile by the triple bond -is observed very rarely [27,50] and manifests in vibrational spectra as low-frequency shift of (C N). This situation was not observed in the PBAN-CoCl 2 system under study.…”

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

“…To explain this difference, one has to consider the nature of the chemical bond in nitrile and olefin complexes with transition metal ions. The chemical bond in complexes containing ligands with multiple bonds is described usually in terms of the Dewar-Chatt-Duncanson model [27][28][29]50].…”

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

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Influence of metal coordination on conductivity behavior in poly(butadiene–acrylonitrile)–CoCl2 system

Бушкова

Koryakova

Skorik

et al. 2008

Electrochimica Acta

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Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 96%

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 97%

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

Section: Correlation Between the Composition Of Complex Species And Tmentioning

confidence: 99%

See 3 more Smart Citations

Influence of metal coordination on conductivity behavior in poly(butadiene–acrylonitrile)–CoCl2 system

Бушкова

Koryakova

Skorik

et al. 2008

Electrochimica Acta

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Isocyanide Binding Modes on Metal Surfaces and in Metal Complexes

Lazăr

Angelici

2009

Modern Surface Organometallic Chemistry

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Synthesis of Linear (Z)‐α,β‐Unsaturated Esters by Catalytic Cross‐Metathesis. The Influence of Acetonitrile

Johnson

Hoveyda

et al. 2016

Angewandte Chemie

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Kinetically-controlled catalytic cross-metathesis reactions that generate (Z)-α,β-unsaturated esters selectively are disclosed. A key finding is that the presence of acetonitrile obviates the need for using excess amounts of a more valuable terminal alkene substrates. On the basis of X-ray structure and spectroscopic investigations a rationale for the positive impact of acetonitrile is provided. Transformations leading to various E,Z-dienoates are highly Z-selective as well. Utility is highlighted by application to stereoselective synthesis of the C1-C12 fragment of biologically active natural product (−)-laulimalide. Keywordsalkenes; catalysis; enoates; cross-metathesis; dienoates; synthesis; molybdenum Conspicuously absent from the list of available kinetically-controlled stereoselective olefin metathesis reactions [1,2] are cross-metathesis (CM) processes that can deliver linear (Z)-α,β-unsaturated esters. [3,4,5] Such transformations would offer a valuable disconnection that may be complementary to Wittig-type [6] or alkyne partial hydrogenation reactions. [7] A case in point is a possible stereoselective route to the C1-C12 segment of (−)-laulimalide, a naturally occurring microtubule stabilizing agent (Scheme 1a). [8] Z-Enoate i could accordingly be synthesized through two Z-selective CM steps (ii→i and v→iv). Small-ring * amir.hoveyda@bc.edu. HHS Public Access Author ManuscriptAuthor Manuscript Author ManuscriptAuthor Manuscript lactones are accessible through ring-closing metathesis (RCM), but because of carbonyl coordination to the metal center, these processes are at times inefficient and demand elevated temperatures and relatively high catalyst loadings (e.g., 20 mol %). [9] In such instances a Lewis acidic additive can enhance efficiency [10] but not always. [11] Development of a Z-selective enoate CM requires that the following problems are resolved (Scheme 1b): 1) The carbonyl unit of a carboxylic ester-substituted alkylidene might coordinate to the metal center to reduce reaction rates. 2) High efficiency might demand larger amounts of a structurally complex alkenyl compound. For example, excess of the more valuable α-alkenes ii or v might be required for high efficiency (Scheme 1a). 3) Electronic factors do not favor formation of productive metallacyclobutanes. Unlike macrocyclic RCM reactions, [12] where geometric constraints oppose the mismatched electronic factors (see I, Scheme 1b), in CM formation of electronically (and sterically) favored intermediates II-III would lead to nonproductive metallacyclobutanes (vs. IV-V, Scheme 1b). The active complex must therefore be sufficiently long living for productive CM that occurs subsequent to nonproductive cycles.We began by probing the ability of a number of complexes to promote CM between 1-decene (3.0 equiv.) and acrylate 1a (Table 1). With Ru-1 [13] formation of Z-2a was fully Zselective but inefficient (Table 1, entry 1) and with Ru-2 [5e] none of the expected product was formed (entry 2). Reaction with bis-alkoxide Mo-1 proceeded only ...

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Theoretical studies of transition metal complexes with nitriles and isocyanides

Abstract: For Abstract see ChemInform Abstract in Full Text.

Cited by 64 publications

References 66 publications

Influence of metal coordination on conductivity behavior in poly(butadiene–acrylonitrile)–CoCl2 system

Influence of metal coordination on conductivity behavior in poly(butadiene–acrylonitrile)–CoCl2 system

Isocyanide Binding Modes on Metal Surfaces and in Metal Complexes

Synthesis of Linear (Z)‐α,β‐Unsaturated Esters by Catalytic Cross‐Metathesis. The Influence of Acetonitrile

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