Chiral diphosphine derivatives of alkylidyne tricobalt carbonyl clusters - A comparative study of different cobalt carbonyl (pre)catalysts for (asymmetric) intermolecular Pauson-Khand reactions
(2016) In Polyhedron 103. p.275-282- Abstract
- Reaction of the tricobalt carbyne cluster [Co-3(mu(3)-CH)(CO)(9)] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co-3(mu(3)-CH)(CO)(7)(P-P*)] in good yield (P-P* = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co-3(mu(3)-CH)(CO)(7)(mu-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalysts/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When the chiral diphosphine ligands were used as... (More)
- Reaction of the tricobalt carbyne cluster [Co-3(mu(3)-CH)(CO)(9)] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co-3(mu(3)-CH)(CO)(7)(P-P*)] in good yield (P-P* = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co-3(mu(3)-CH)(CO)(7)(mu-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalysts/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When the chiral diphosphine ligands were used as promoters/auxiliary ligands for the same Pauson-Khand reaction, using either [Co-2(CO)(8)] or [Co-4(CO)(12)] as catalyst precursors, both the overall yields and the selectivities with respect to cyclopentenone formation were significantly improved. The best results were obtained for ligands J007 and W001, with [Co-4(CO)12] as pre-catalyst, where yields of 96%, and virtually 100% selectivity were obtained. However, the enantioselectivity of product formation was low or non-existent. The crystal structure of [Co-3(mu(3)-CH)(CO)(7)(mu-J004)] is described. [J003 = [(R)-1-{(S)-2-(dicyclohexylphosphino)-ferrocenyl} ethyldicyclohexylphosphine], J004 = [(R)-1-{(S)-2-(dicyclohexylphosphino)-ferrocenyl} ethyldiphenylphosphine], J005 = [(R)-1-{(S)-2-(diphenylphosphino)ferrocenyl}ethyl-di-3,5-xylylphosphine], J007 = [(R)-1-{(S)-2-di-(4-methoxy-3,5-dimethylphenyl)phosphino)ferrocenyl) ethyldicyclohexylphosphine], W001 = [(R)-1-{(R)-2-(2'-diphenyl phosphinophenyl)ferrocenyl} ethyldi(bis-3,5-trifluoromethylphenyl) phosphine], W003 [(R)-1-{(R)-2-(2'-diphenylphosphino-phenyl)ferrocenyl}ethyldi(3,5-xylyl)phosphine]. (C) 2015 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8747814
- author
- Mottalib, Abdul LU ; Haukka, Matti and Nordlander, Ebbe LU
- organization
- publishing date
- 2016
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Cluster, Chirality, Enantioselectivity, Pauson-Khand reaction, Catalysis
- in
- Polyhedron
- volume
- 103
- pages
- 275 - 282
- publisher
- Elsevier
- external identifiers
-
- wos:000367761400011
- scopus:84949112992
- ISSN
- 0277-5387
- DOI
- 10.1016/j.poly.2015.04.021
- language
- English
- LU publication?
- yes
- id
- e6a9292f-5bcf-46c8-b478-ff0573c061b4 (old id 8747814)
- date added to LUP
- 2016-04-01 14:51:44
- date last changed
- 2022-04-22 05:36:05
@article{e6a9292f-5bcf-46c8-b478-ff0573c061b4,
abstract = {{Reaction of the tricobalt carbyne cluster [Co-3(mu(3)-CH)(CO)(9)] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co-3(mu(3)-CH)(CO)(7)(P-P*)] in good yield (P-P* = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co-3(mu(3)-CH)(CO)(7)(mu-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalysts/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When the chiral diphosphine ligands were used as promoters/auxiliary ligands for the same Pauson-Khand reaction, using either [Co-2(CO)(8)] or [Co-4(CO)(12)] as catalyst precursors, both the overall yields and the selectivities with respect to cyclopentenone formation were significantly improved. The best results were obtained for ligands J007 and W001, with [Co-4(CO)12] as pre-catalyst, where yields of 96%, and virtually 100% selectivity were obtained. However, the enantioselectivity of product formation was low or non-existent. The crystal structure of [Co-3(mu(3)-CH)(CO)(7)(mu-J004)] is described. [J003 = [(R)-1-{(S)-2-(dicyclohexylphosphino)-ferrocenyl} ethyldicyclohexylphosphine], J004 = [(R)-1-{(S)-2-(dicyclohexylphosphino)-ferrocenyl} ethyldiphenylphosphine], J005 = [(R)-1-{(S)-2-(diphenylphosphino)ferrocenyl}ethyl-di-3,5-xylylphosphine], J007 = [(R)-1-{(S)-2-di-(4-methoxy-3,5-dimethylphenyl)phosphino)ferrocenyl) ethyldicyclohexylphosphine], W001 = [(R)-1-{(R)-2-(2'-diphenyl phosphinophenyl)ferrocenyl} ethyldi(bis-3,5-trifluoromethylphenyl) phosphine], W003 [(R)-1-{(R)-2-(2'-diphenylphosphino-phenyl)ferrocenyl}ethyldi(3,5-xylyl)phosphine]. (C) 2015 Elsevier Ltd. All rights reserved.}},
author = {{Mottalib, Abdul and Haukka, Matti and Nordlander, Ebbe}},
issn = {{0277-5387}},
keywords = {{Cluster; Chirality; Enantioselectivity; Pauson-Khand reaction; Catalysis}},
language = {{eng}},
pages = {{275--282}},
publisher = {{Elsevier}},
series = {{Polyhedron}},
title = {{Chiral diphosphine derivatives of alkylidyne tricobalt carbonyl clusters - A comparative study of different cobalt carbonyl (pre)catalysts for (asymmetric) intermolecular Pauson-Khand reactions}},
url = {{http://dx.doi.org/10.1016/j.poly.2015.04.021}},
doi = {{10.1016/j.poly.2015.04.021}},
volume = {{103}},
year = {{2016}},
}