Pentacarbonylhydridochromates M+[HCr(CO)5]−: Reactivity in Organic Synthesis and Homogeneous Catalysis

Brunet, Jean‐Jacques

doi:10.1002/1099-0682(200007)2000:7<1377::aid-ejic1377>3.0.co;2-h

Cited by 9 publications

(6 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 H NMR (C 6 D 6 ): 3.25 (hept, 3 J HH = 6 Hz, 1H, OCH), 1.40 (s, br, 12H, PMe), 1.29 (s, br, 12H, PMe‘), 1.35 (m, 8H, PCH 2 ), 0.87 (d, 3 J HH = 6 Hz, 6H, −CH 3 ). 13 C{ 1 H} NMR (C 6 D 6 ): 69.3 (quint, 3 J CP = 3.6 Hz, OCH), 30.4 (quint, J CP = 9.8 Hz, PCH 2 ), 29.9 (s, CH 3 ), 15.4 (m, PMe). 31 P{ 1 H} NMR (C 6 D 6 ): 32.8 (s).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

et al. 2003

View full text Add to dashboard Cite

The synthesis of the tetraphosphine-substituted molybdenum hydride complex trans-Mo(dmpe)2(H)(NO) (3) (dmpe = bis(dimethylphosphino)ethane) is described, which is obtained by starting from the known compound Mo(CO)4(NO)(ClAlCl3) via the isolable chloride trans-Mo(Cl)(dmpe)2(NO) (1) and the borohydride trans-Mo(η1-BH4)(dmpe)2(NO) (2). Two deuteride complexes trans-Mo(dmpe)2(D)(NO) (3a) and mer-Mo(CO)(D)(NO)(PMe3)3 (4) have been prepared. From these the Mo−D bond ionicities of both deuterides were obtained via determinations of the deuterium quadrupole coupling constants (DQCC) in solution from T 1min measurements of the 2H nucleus and in solid state from static 2H NMR spectra. A strongly polar character of the Mo−D(H) bond was found for 3 and 4. In agreement with its enhanced hydridicity 3 revealed a very high propensity for hydride transfer reactions. It reacted readily with benzophenone, acetophenone, and acetone to afford the corresponding alkoxide complexes trans-Mo(dmpe)2(NO)(OCHRR‘) (R = R‘ = Ph (5); R = Me, R‘ = Ph (6); R = R‘ = Me (7)). 3 also underwent rapid insertion with Fe(CO)5 and Re2(CO)10 to afford μ-formyl complexes Mo(dmpe)2(NO)[(μ-OCH)Fe(CO)4] (8) and Mo(dmpe)2(NO)[(μ-OCH)Re2(CO)9] (9), respectively. Furthermore, reversible double insertion of 3 into Re2(CO)10 was observed, which furnished the (ON)(dmpe)2Mo(μ-OCH)Re2(CO)8(μ-CHO)Mo(dmpe)2(NO) complex (10). For this reaction equilibrium constants were determined by VT-NMR measurements. ΔH and ΔS amount to −58.8 ± 2.7 kJ mol-1 and −48 ± 2 J·K-1.mol-1. The reaction of 3 with Mn2(CO)10 gave the μ-carbonyl complex Mo(dmpe)2(NO)[(μ-OC)Mn(CO)4] (12) via the intermediacy of Mo(dmpe)2(NO)[(μ-OCH)Mn2(CO)9] (11). The structures of compounds 1, 2, 8, 9, 10, and 12 were studied by single-crystal X-ray diffraction.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Transition metal hydrides are useful reagents in many stoichiometric reactions and important intermediates in a large number of catalytic conversions . In many such hydrogenations using transition metal hydrides the proper balance of proton or hydride transfer capabilities is important .…”

Section: Introductionmentioning

confidence: 99%

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

et al. 2003

View full text Add to dashboard Cite

show abstract

“…rather than a non-transition-metalbased acid has been suggested. 168 Compared to the catalysis with HFe(CO) 4…”

Section: Catalysis Involving Ionic Mechanismsmentioning

confidence: 99%

First-row transition metal catalyzed reduction of carbonyl functionalities: a mechanistic perspective

2010

View full text Add to dashboard Cite

The use of first-row transition metals for the catalytic reduction of carbonyl functionalities has become increasingly important in homogeneous catalysis. This Perspective examines the mechanistic aspects of these reduction reactions, with a focus on various interactions between metal complexes and substrates. Four different types of catalytic pathways, namely catalysis with dihydride (or dihydrogen) complexes, catalysis with monohydride complexes, metal-ligand bifunctional catalysis, and catalysis involving ionic mechanisms, are discussed with recent examples highlighted.

show abstract

“…Although the exact mechanism involved in these reactions is not known, Darensbourg et al have reported convincing data indicating that the dinuclear hydride Na + (μ-H)[Cr(CO) 5 ] 2 - may be the intermediate on which the carbonyl substitution occurs, either in ethanol or in THF . Since K + (μ-H)[Cr(CO) 5 ] 2 - , 3 , may result from the evolution of 2 , we were interested in comparing the reaction of PEt 3 with 2 and 3 under the same conditions. Thus, the reaction of 3 (free of any trace of 2 ) with 4 equiv of PEt 3 was performed in CD 3 CN in a NMR sealed tube at room temperature.…”

Section: Resultsmentioning

confidence: 99%

“…As part of our interest in the applications of hydridocarbonylmetalates in organic synthesis and homogeneous catalysis, , we recently investigated the study of the reactivity of the group VI analogue K + [HCr(CO) 5 ] - , 2 , in organic synthesis. − In addition, in light of the coordination chemistry developed with 1 , we were obviously interested in examining the reaction of 2 with phosphanes. In a short comparative study of the coordination chemistry of 1 and 2 , we already noticed some differences, which were tentatively attributed to the lower acidity of 2 as compared to that of 1 .…”

Section: Introductionmentioning

confidence: 99%

Ligand Substitution Processes on Carbonylmetal Derivatives. 3.¹Reaction of Hydridopentacarbonylchromates with Phosphines

et al. 2002

Self Cite

View full text Add to dashboard Cite

The reaction of K + [HCr(CO) 5 ]with phosphanes PR 3 (R ) Et, Ph, NMe 2 ) in THF at 65 °C affords the disubstituted complexes trans-Cr(CO) 4 (PR 3 ) 2 isolated in 57-70% yield. The X-ray crystal structures of trans-Cr(CO) 4 (PR 3 ) 2 derivatives have been determined for R ) Et and NMe 2 . These reactions proceed first by exchange of one carbon monoxide ligand, generating the monosubstituted hydridotetracarbonylchromates K + [HCr(CO) 4 PR 3 ] -, observed and characterized by NMR spectroscopy for R ) Et and Ph. The second step involves substitution of the hydride ligand of K + [HCr(CO) 4 PR 3 ]to give the disubstituted derivatives trans-Cr(CO) 4 (PR 3 ) 2 . These ligand exchange processes are discussed and compared with the reaction of phosphanes with the dinuclear bridged K + (µ-H)[Cr(CO) 5 ] 2 -.

show abstract

Pentacarbonylhydridochromates M+[HCr(CO)5]−: Reactivity in Organic Synthesis and Homogeneous Catalysis

Cited by 9 publications

References 76 publications

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

First-row transition metal catalyzed reduction of carbonyl functionalities: a mechanistic perspective

Ligand Substitution Processes on Carbonylmetal Derivatives. 3.¹Reaction of Hydridopentacarbonylchromates with Phosphines

Contact Info

Product

Resources

About

Pentacarbonylhydridochromates M+[HCr(CO)5]−: Reactivity in Organic Synthesis and Homogeneous Catalysis

Cited by 9 publications

References 76 publications

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

Hydridic Character and Reactivity of Di[1,2-bis- (dimethylphosphino)ethane]hydridonitrosylmolybdenum(0)

First-row transition metal catalyzed reduction of carbonyl functionalities: a mechanistic perspective

Ligand Substitution Processes on Carbonylmetal Derivatives. 3.1Reaction of Hydridopentacarbonylchromates with Phosphines

Contact Info

Product

Resources

About

Ligand Substitution Processes on Carbonylmetal Derivatives. 3.¹Reaction of Hydridopentacarbonylchromates with Phosphines