Synthesis of cis - and trans-diisothiocyanato-bis(NHC) complexes of nickel(II) and applications in the Kumada-Corriu reaction

Handle URI:
http://hdl.handle.net/10754/561521
Title:
Synthesis of cis - and trans-diisothiocyanato-bis(NHC) complexes of nickel(II) and applications in the Kumada-Corriu reaction
Authors:
Jothibasu, Ramasamy; Huang, Kuo-Wei ( 0000-0003-1900-2658 ) ; Huynh, Hanvinh
Abstract:
Metathetical reaction of AgSCN with a series of trans-dihalido-bis(carbene) nickel(II) complexes in CH3CN readily afforded the novel diisothiocyanato-bis(carbene) complexes [Ni(NCS)2(NHC)2] (trans-2a, NHC = 1,3-diisopropylbenzimidazolin-2-ylidene; trans-2b, NHC = 1,3-diisobutylbenzimidazolin-2-ylidene; trans-2c, NHC = 1,3- dibenzylbenzimidazolin-2-ylidene; cis-2d, NHC = 1,3-di(2-propenyl) benzimidazolin-2-ylidene; cis-2e, NHC = 1-propyl-3-methylbenzimidazolin-2- ylidene) as greenish-yellow powders in moderate to good yields. While dihalido-bis(carbene) Ni(II) complexes exclusively form trans-complexes, a trans-cis isomerization occurs upon halido-isothiocyanato exchange with complexes bearing less bulky carbene ligands, i.e., cis-2d/e. DFT calculations indicated that this isomerization can be attributed to a reduced energy difference between trans- and cis-isomers of diisothiocyanato complexes. All complexes have been characterized by multinuclear NMR spectroscopy, ESI mass spectrometry, and X-ray diffraction analysis. A catalytic study revealed that cis-complexes generally exhibit greater activities in the Kumada-Corriu coupling reaction. © 2010 American Chemical Society.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; KAUST Catalysis Center (KCC); Chemical Science Program; Physical Sciences and Engineering (PSE) Division; HCL
Publisher:
American Chemical Society
Journal:
Organometallics
Issue Date:
13-Sep-2010
DOI:
10.1021/om100241v
Type:
Article
ISSN:
02767333
Sponsors:
Financial support from National University of Singapore (WBS R-143-000-327-133) to H.V.H and KAUST baseline funding to K.-W.H. is acknowledged. Technical support from staff at the CMMAC of the NUS Chemistry Department is appreciated. R.J. thanks NUS for a research scholarship.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorJothibasu, Ramasamyen
dc.contributor.authorHuang, Kuo-Weien
dc.contributor.authorHuynh, Hanvinhen
dc.date.accessioned2015-08-02T09:13:22Zen
dc.date.available2015-08-02T09:13:22Zen
dc.date.issued2010-09-13en
dc.identifier.issn02767333en
dc.identifier.doi10.1021/om100241ven
dc.identifier.urihttp://hdl.handle.net/10754/561521en
dc.description.abstractMetathetical reaction of AgSCN with a series of trans-dihalido-bis(carbene) nickel(II) complexes in CH3CN readily afforded the novel diisothiocyanato-bis(carbene) complexes [Ni(NCS)2(NHC)2] (trans-2a, NHC = 1,3-diisopropylbenzimidazolin-2-ylidene; trans-2b, NHC = 1,3-diisobutylbenzimidazolin-2-ylidene; trans-2c, NHC = 1,3- dibenzylbenzimidazolin-2-ylidene; cis-2d, NHC = 1,3-di(2-propenyl) benzimidazolin-2-ylidene; cis-2e, NHC = 1-propyl-3-methylbenzimidazolin-2- ylidene) as greenish-yellow powders in moderate to good yields. While dihalido-bis(carbene) Ni(II) complexes exclusively form trans-complexes, a trans-cis isomerization occurs upon halido-isothiocyanato exchange with complexes bearing less bulky carbene ligands, i.e., cis-2d/e. DFT calculations indicated that this isomerization can be attributed to a reduced energy difference between trans- and cis-isomers of diisothiocyanato complexes. All complexes have been characterized by multinuclear NMR spectroscopy, ESI mass spectrometry, and X-ray diffraction analysis. A catalytic study revealed that cis-complexes generally exhibit greater activities in the Kumada-Corriu coupling reaction. © 2010 American Chemical Society.en
dc.description.sponsorshipFinancial support from National University of Singapore (WBS R-143-000-327-133) to H.V.H and KAUST baseline funding to K.-W.H. is acknowledged. Technical support from staff at the CMMAC of the NUS Chemistry Department is appreciated. R.J. thanks NUS for a research scholarship.en
dc.publisherAmerican Chemical Societyen
dc.titleSynthesis of cis - and trans-diisothiocyanato-bis(NHC) complexes of nickel(II) and applications in the Kumada-Corriu reactionen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentHCLen
dc.identifier.journalOrganometallicsen
dc.contributor.institutionDepartment of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singaporeen
kaust.authorHuang, Kuo-Weien
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