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Novel pyrazolylphosphite- and pyrazolylphosphinite-ruthenium(II) complexes as catalysts for hydrogenation of acetophenone

Amenuvor, Gershon; Obuah, Collins; Nordlander, Ebbe LU and Darkwa, James (2016) In Dalton Transactions 45(34). p.13514-13524
Abstract

The new compounds and potential ligands 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiphenlyphosphinite (L1), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L2), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyl-diethylphosphite (L3) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L4) were prepared from the reaction of (3,5-(disubstituted)pyrazol-1H-yl)ethanol and the appropriate phosphine chloride. The phosphinite (L1) and phosphites (L2-L4) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L5) were reacted with [Ru(p-cymene)Cl2]2 to afford the ruthenium(ii) complexes [Ru(p-cymene)Cl2(L1)] (1), [Ru(p-cymene)Cl2(L2)] (2), [Ru(p-cymene)Cl2(L3)] (3),... (More)

The new compounds and potential ligands 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiphenlyphosphinite (L1), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L2), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyl-diethylphosphite (L3) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L4) were prepared from the reaction of (3,5-(disubstituted)pyrazol-1H-yl)ethanol and the appropriate phosphine chloride. The phosphinite (L1) and phosphites (L2-L4) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L5) were reacted with [Ru(p-cymene)Cl2]2 to afford the ruthenium(ii) complexes [Ru(p-cymene)Cl2(L1)] (1), [Ru(p-cymene)Cl2(L2)] (2), [Ru(p-cymene)Cl2(L3)] (3), [Ru(p-cymene)Cl2(L4)] (4), and [Ru(p-cymene)Cl2(L5)] (5). All ruthenium complexes were characterized by a combination of NMR spectroscopy, elemental analysis and, in selected cases, by single crystal X-ray crystallography. Complexes 1-5 and [Ru(p-cymene)Cl2(L6)] (6) (prepared from 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L6)) were investigated as catalysts for both transfer and molecular hydrogenation of acetophenone to 1-phenylethanol. At 80 °C the percent conversion of acetophenone in transfer hydrogenation was moderate to high over 10 h (42-87%); for molecular hydrogenation acetophenone, conversions were as high as 98% in 6 h.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Dalton Transactions
volume
45
issue
34
pages
11 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:84983655876
  • wos:000382144300031
ISSN
1477-9226
DOI
10.1039/c6dt02164f
language
English
LU publication?
yes
id
cf61948f-a65a-495d-b1fc-125a2f1f3682
date added to LUP
2017-02-22 15:22:03
date last changed
2017-11-12 04:29:47
@article{cf61948f-a65a-495d-b1fc-125a2f1f3682,
  abstract     = {<p>The new compounds and potential ligands 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiphenlyphosphinite (L1), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L2), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyl-diethylphosphite (L3) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiethylphosphite (L4) were prepared from the reaction of (3,5-(disubstituted)pyrazol-1H-yl)ethanol and the appropriate phosphine chloride. The phosphinite (L1) and phosphites (L2-L4) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L5) were reacted with [Ru(p-cymene)Cl<sub>2</sub>]<sub>2</sub> to afford the ruthenium(ii) complexes [Ru(p-cymene)Cl<sub>2</sub>(L1)] (1), [Ru(p-cymene)Cl<sub>2</sub>(L2)] (2), [Ru(p-cymene)Cl<sub>2</sub>(L3)] (3), [Ru(p-cymene)Cl<sub>2</sub>(L4)] (4), and [Ru(p-cymene)Cl<sub>2</sub>(L5)] (5). All ruthenium complexes were characterized by a combination of NMR spectroscopy, elemental analysis and, in selected cases, by single crystal X-ray crystallography. Complexes 1-5 and [Ru(p-cymene)Cl<sub>2</sub>(L6)] (6) (prepared from 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L6)) were investigated as catalysts for both transfer and molecular hydrogenation of acetophenone to 1-phenylethanol. At 80 °C the percent conversion of acetophenone in transfer hydrogenation was moderate to high over 10 h (42-87%); for molecular hydrogenation acetophenone, conversions were as high as 98% in 6 h.</p>},
  author       = {Amenuvor, Gershon and Obuah, Collins and Nordlander, Ebbe and Darkwa, James},
  issn         = {1477-9226},
  language     = {eng},
  number       = {34},
  pages        = {13514--13524},
  publisher    = {Royal Society of Chemistry},
  series       = {Dalton Transactions},
  title        = {Novel pyrazolylphosphite- and pyrazolylphosphinite-ruthenium(II) complexes as catalysts for hydrogenation of acetophenone},
  url          = {http://dx.doi.org/10.1039/c6dt02164f},
  volume       = {45},
  year         = {2016},
}