Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones

Barbara F M Kimmich, Paul J. Fagan, Elisabeth Hauptman, William J. Marshall, R Morris Bullock

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

The heterodifunctional ligand Li[η 5-C 5H 4(CH 2) 2PR 2] (R = Ph, Cy, and Bu) reacts with Mo(CO) 3(diglyme) to give the molybdenum anion complex Li{Mo(CO) 35-C 5H 4(CH 2) 2PR 2]}. Protonation with HOAc gives the metal hydride complexes HMo(CO) 251- C 5H 4(CH 2) 2PR 2], in which the phosphine and cyclopentadienyl ligands are linked by a two-carbon bridge. Crystal structures of HMo(CO) 25:n 1-C 5H 4CH 2) 2PR 2] with all three R groups (R = Ph, Cy, and tBu) are reported. Syntheses of the C 3-bridged complex, HMo(CO) 25: η 1-C 4H 5(CH 2) 3- PPh 2], and a W analogue, HW(CO) 35-C 5H 4(CH 2) 2P tBu 2], were carried out by analogous routes. Hydride transfer to Ph 3C +BAr′ 4; [Ar′ = 3,5-bis(trifluoromethyl)phenyl] from the catalyst precursors HMo(CO) 251-C 5H 4(CH 2) 2PR 2] leads to homogeneous catalysts for hydrogenation of ketones, with the best performance being found for R = Cy. Protonation of HMo(CO) 25: η 1-C 5H 4(CH 2) 2PR 2] by HOTf leads to metal triflate complexes (TfO)Mo(CO) 251-C 5H 4(CH 2) 2PR 2], which are used in ketone hydrogenation. Compared to the previously prepared complexes that did not have the phosphine and Cp linked together, these new complexes provide catalysts that have much longer lifetimes (up to about 500 turnovers) and higher thermal stability. Solvent-free ketone hydrogenation can be carried out with these complexes at catalyst loadings as low as 0.1 mol%.

Original languageEnglish
Pages (from-to)6220-6229
Number of pages10
JournalOrganometallics
Volume24
Issue number25
DOIs
Publication statusPublished - Dec 5 2005

Fingerprint

Molybdenum
Carbon Monoxide
Ketones
ketones
Hydrogenation
hydrogenation
molybdenum
methylidyne
phosphine
catalysts
Catalysts
Protonation
phosphines
Hydrides
ligands
Ligands
metal hydrides
Metal complexes
hydrides
thermal stability

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Organic Chemistry

Cite this

Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones. / Kimmich, Barbara F M; Fagan, Paul J.; Hauptman, Elisabeth; Marshall, William J.; Bullock, R Morris.

In: Organometallics, Vol. 24, No. 25, 05.12.2005, p. 6220-6229.

Research output: Contribution to journalArticle

Kimmich, Barbara F M ; Fagan, Paul J. ; Hauptman, Elisabeth ; Marshall, William J. ; Bullock, R Morris. / Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones. In: Organometallics. 2005 ; Vol. 24, No. 25. pp. 6220-6229.
@article{0bb6ce3cbb744c65a1908936b7fa5245,
title = "Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones",
abstract = "The heterodifunctional ligand Li[η 5-C 5H 4(CH 2) 2PR 2] (R = Ph, Cy, and Bu) reacts with Mo(CO) 3(diglyme) to give the molybdenum anion complex Li{Mo(CO) 3[η 5-C 5H 4(CH 2) 2PR 2]}. Protonation with HOAc gives the metal hydride complexes HMo(CO) 2[η 5:η 1- C 5H 4(CH 2) 2PR 2], in which the phosphine and cyclopentadienyl ligands are linked by a two-carbon bridge. Crystal structures of HMo(CO) 2[η 5:n 1-C 5H 4CH 2) 2PR 2] with all three R groups (R = Ph, Cy, and tBu) are reported. Syntheses of the C 3-bridged complex, HMo(CO) 2[η 5: η 1-C 4H 5(CH 2) 3- PPh 2], and a W analogue, HW(CO) 3[η 5-C 5H 4(CH 2) 2P tBu 2], were carried out by analogous routes. Hydride transfer to Ph 3C +BAr′ 4; [Ar′ = 3,5-bis(trifluoromethyl)phenyl] from the catalyst precursors HMo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2] leads to homogeneous catalysts for hydrogenation of ketones, with the best performance being found for R = Cy. Protonation of HMo(CO) 2[η 5: η 1-C 5H 4(CH 2) 2PR 2] by HOTf leads to metal triflate complexes (TfO)Mo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2], which are used in ketone hydrogenation. Compared to the previously prepared complexes that did not have the phosphine and Cp linked together, these new complexes provide catalysts that have much longer lifetimes (up to about 500 turnovers) and higher thermal stability. Solvent-free ketone hydrogenation can be carried out with these complexes at catalyst loadings as low as 0.1 mol{\%}.",
author = "Kimmich, {Barbara F M} and Fagan, {Paul J.} and Elisabeth Hauptman and Marshall, {William J.} and Bullock, {R Morris}",
year = "2005",
month = "12",
day = "5",
doi = "10.1021/om050564h",
language = "English",
volume = "24",
pages = "6220--6229",
journal = "Organometallics",
issn = "0276-7333",
publisher = "American Chemical Society",
number = "25",

}

TY - JOUR

T1 - Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones

AU - Kimmich, Barbara F M

AU - Fagan, Paul J.

AU - Hauptman, Elisabeth

AU - Marshall, William J.

AU - Bullock, R Morris

PY - 2005/12/5

Y1 - 2005/12/5

N2 - The heterodifunctional ligand Li[η 5-C 5H 4(CH 2) 2PR 2] (R = Ph, Cy, and Bu) reacts with Mo(CO) 3(diglyme) to give the molybdenum anion complex Li{Mo(CO) 3[η 5-C 5H 4(CH 2) 2PR 2]}. Protonation with HOAc gives the metal hydride complexes HMo(CO) 2[η 5:η 1- C 5H 4(CH 2) 2PR 2], in which the phosphine and cyclopentadienyl ligands are linked by a two-carbon bridge. Crystal structures of HMo(CO) 2[η 5:n 1-C 5H 4CH 2) 2PR 2] with all three R groups (R = Ph, Cy, and tBu) are reported. Syntheses of the C 3-bridged complex, HMo(CO) 2[η 5: η 1-C 4H 5(CH 2) 3- PPh 2], and a W analogue, HW(CO) 3[η 5-C 5H 4(CH 2) 2P tBu 2], were carried out by analogous routes. Hydride transfer to Ph 3C +BAr′ 4; [Ar′ = 3,5-bis(trifluoromethyl)phenyl] from the catalyst precursors HMo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2] leads to homogeneous catalysts for hydrogenation of ketones, with the best performance being found for R = Cy. Protonation of HMo(CO) 2[η 5: η 1-C 5H 4(CH 2) 2PR 2] by HOTf leads to metal triflate complexes (TfO)Mo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2], which are used in ketone hydrogenation. Compared to the previously prepared complexes that did not have the phosphine and Cp linked together, these new complexes provide catalysts that have much longer lifetimes (up to about 500 turnovers) and higher thermal stability. Solvent-free ketone hydrogenation can be carried out with these complexes at catalyst loadings as low as 0.1 mol%.

AB - The heterodifunctional ligand Li[η 5-C 5H 4(CH 2) 2PR 2] (R = Ph, Cy, and Bu) reacts with Mo(CO) 3(diglyme) to give the molybdenum anion complex Li{Mo(CO) 3[η 5-C 5H 4(CH 2) 2PR 2]}. Protonation with HOAc gives the metal hydride complexes HMo(CO) 2[η 5:η 1- C 5H 4(CH 2) 2PR 2], in which the phosphine and cyclopentadienyl ligands are linked by a two-carbon bridge. Crystal structures of HMo(CO) 2[η 5:n 1-C 5H 4CH 2) 2PR 2] with all three R groups (R = Ph, Cy, and tBu) are reported. Syntheses of the C 3-bridged complex, HMo(CO) 2[η 5: η 1-C 4H 5(CH 2) 3- PPh 2], and a W analogue, HW(CO) 3[η 5-C 5H 4(CH 2) 2P tBu 2], were carried out by analogous routes. Hydride transfer to Ph 3C +BAr′ 4; [Ar′ = 3,5-bis(trifluoromethyl)phenyl] from the catalyst precursors HMo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2] leads to homogeneous catalysts for hydrogenation of ketones, with the best performance being found for R = Cy. Protonation of HMo(CO) 2[η 5: η 1-C 5H 4(CH 2) 2PR 2] by HOTf leads to metal triflate complexes (TfO)Mo(CO) 2[η 5:η 1-C 5H 4(CH 2) 2PR 2], which are used in ketone hydrogenation. Compared to the previously prepared complexes that did not have the phosphine and Cp linked together, these new complexes provide catalysts that have much longer lifetimes (up to about 500 turnovers) and higher thermal stability. Solvent-free ketone hydrogenation can be carried out with these complexes at catalyst loadings as low as 0.1 mol%.

UR - http://www.scopus.com/inward/record.url?scp=28944454500&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=28944454500&partnerID=8YFLogxK

U2 - 10.1021/om050564h

DO - 10.1021/om050564h

M3 - Article

VL - 24

SP - 6220

EP - 6229

JO - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 25

ER -