(Pyrazol-l-ylmethyl)pyridine nickel complexes: Ethylene oligomerization and unusual friedel - crafts alkylation catalysts

Stephen O. Ojwach; Ilia A. Guzei; Letitia L. Benade; Selwyn F. Mapolie; James Darkwa

doi:10.1021/om8006322

(Pyrazol-l-ylmethyl)pyridine nickel complexes: Ethylene oligomerization and unusual friedel - crafts alkylation catalysts

Stephen O. Ojwach, Ilia A. Guzei, Letitia L. Benade, Selwyn F. Mapolie, James Darkwa

Chemical Sciences

Research output: Contribution to journal › Article › peer-review

90 Citations (Scopus)

Abstract

The reactions of 2,6-bis(3,5-dimethylpyrazol-l-ylmethyl)pyridine (L1) and 2,6-bis(3,5-di-rert-butylpyrazol-l-ylmethyl)pyridine (L2) with NiCl ₂ or NiBr ₂ gave the nickel(II) complexes [NiCl ₂(Ll)] (1), [NiBr ₂(Ll)] (2), [NiCl ₂(L2)] (3), and [NiBr ₂(L2)] (4) in high yields. Compounds 2-(3,5-dimethylpyrazol-l- ylmethyl)pyridine (L3) and 2-(3,5-di-tert-butylpyrazol-l-ylmethyl)pyridine (L4) on the other hand gave either mononuclear or dinuclear nickel(II) complexes, depending on the steric bulk of the substituents on the pyrazolyl unit. While L3 gave the dinuclear complexes [Ni ₂(μ ₂-C1) ₂C1 ₂(L3) ₂] (5) and [Ni ₂(μ ₂-Br) ₂Br ₂(L3) ₂] (6), L4 gave the mononuclear complexes [NiCl ₂(L4)] (7) and [NiBr ₂(L4)] (8). Activation of 1-8 with EtAlCl ₂ resulted in the oligomerization of ethylene to C ₄, C ₆, and C ₈ alkenes, followed by subsequent Friedel - Crafts alkylation of the toluene solvent. Activities as high as 15 660 kg of alkylated products/mol Ni/h were observed for 5 at 40 bar. However, when hexane was used as solvent, only trace amounts of alkylated toluene products were observed.

Original language	English
Pages (from-to)	2127-2133
Number of pages	7
Journal	Organometallics
Volume	28
Issue number	7
DOIs	https://doi.org/10.1021/om8006322
Publication status	Published - 13 Apr 2009

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry

Access to Document

10.1021/om8006322

Cite this

@article{8dc31c4d953c47e5a58c55ec04430b27,

title = "(Pyrazol-l-ylmethyl)pyridine nickel complexes: Ethylene oligomerization and unusual friedel - crafts alkylation catalysts",

abstract = "The reactions of 2,6-bis(3,5-dimethylpyrazol-l-ylmethyl)pyridine (L1) and 2,6-bis(3,5-di-rert-butylpyrazol-l-ylmethyl)pyridine (L2) with NiCl 2 or NiBr 2 gave the nickel(II) complexes [NiCl 2(Ll)] (1), [NiBr 2(Ll)] (2), [NiCl 2(L2)] (3), and [NiBr 2(L2)] (4) in high yields. Compounds 2-(3,5-dimethylpyrazol-l- ylmethyl)pyridine (L3) and 2-(3,5-di-tert-butylpyrazol-l-ylmethyl)pyridine (L4) on the other hand gave either mononuclear or dinuclear nickel(II) complexes, depending on the steric bulk of the substituents on the pyrazolyl unit. While L3 gave the dinuclear complexes [Ni 2(μ 2-C1) 2C1 2(L3) 2] (5) and [Ni 2(μ 2-Br) 2Br 2(L3) 2] (6), L4 gave the mononuclear complexes [NiCl 2(L4)] (7) and [NiBr 2(L4)] (8). Activation of 1-8 with EtAlCl 2 resulted in the oligomerization of ethylene to C 4, C 6, and C 8 alkenes, followed by subsequent Friedel - Crafts alkylation of the toluene solvent. Activities as high as 15 660 kg of alkylated products/mol Ni/h were observed for 5 at 40 bar. However, when hexane was used as solvent, only trace amounts of alkylated toluene products were observed.",

author = "Ojwach, {Stephen O.} and Guzei, {Ilia A.} and Benade, {Letitia L.} and Mapolie, {Selwyn F.} and James Darkwa",

year = "2009",

month = apr,

day = "13",

doi = "10.1021/om8006322",

language = "English",

volume = "28",

pages = "2127--2133",

journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

number = "7",

}

TY - JOUR

T1 - (Pyrazol-l-ylmethyl)pyridine nickel complexes

T2 - Ethylene oligomerization and unusual friedel - crafts alkylation catalysts

AU - Ojwach, Stephen O.

AU - Guzei, Ilia A.

AU - Benade, Letitia L.

AU - Mapolie, Selwyn F.

AU - Darkwa, James

PY - 2009/4/13

Y1 - 2009/4/13

N2 - The reactions of 2,6-bis(3,5-dimethylpyrazol-l-ylmethyl)pyridine (L1) and 2,6-bis(3,5-di-rert-butylpyrazol-l-ylmethyl)pyridine (L2) with NiCl 2 or NiBr 2 gave the nickel(II) complexes [NiCl 2(Ll)] (1), [NiBr 2(Ll)] (2), [NiCl 2(L2)] (3), and [NiBr 2(L2)] (4) in high yields. Compounds 2-(3,5-dimethylpyrazol-l- ylmethyl)pyridine (L3) and 2-(3,5-di-tert-butylpyrazol-l-ylmethyl)pyridine (L4) on the other hand gave either mononuclear or dinuclear nickel(II) complexes, depending on the steric bulk of the substituents on the pyrazolyl unit. While L3 gave the dinuclear complexes [Ni 2(μ 2-C1) 2C1 2(L3) 2] (5) and [Ni 2(μ 2-Br) 2Br 2(L3) 2] (6), L4 gave the mononuclear complexes [NiCl 2(L4)] (7) and [NiBr 2(L4)] (8). Activation of 1-8 with EtAlCl 2 resulted in the oligomerization of ethylene to C 4, C 6, and C 8 alkenes, followed by subsequent Friedel - Crafts alkylation of the toluene solvent. Activities as high as 15 660 kg of alkylated products/mol Ni/h were observed for 5 at 40 bar. However, when hexane was used as solvent, only trace amounts of alkylated toluene products were observed.

AB - The reactions of 2,6-bis(3,5-dimethylpyrazol-l-ylmethyl)pyridine (L1) and 2,6-bis(3,5-di-rert-butylpyrazol-l-ylmethyl)pyridine (L2) with NiCl 2 or NiBr 2 gave the nickel(II) complexes [NiCl 2(Ll)] (1), [NiBr 2(Ll)] (2), [NiCl 2(L2)] (3), and [NiBr 2(L2)] (4) in high yields. Compounds 2-(3,5-dimethylpyrazol-l- ylmethyl)pyridine (L3) and 2-(3,5-di-tert-butylpyrazol-l-ylmethyl)pyridine (L4) on the other hand gave either mononuclear or dinuclear nickel(II) complexes, depending on the steric bulk of the substituents on the pyrazolyl unit. While L3 gave the dinuclear complexes [Ni 2(μ 2-C1) 2C1 2(L3) 2] (5) and [Ni 2(μ 2-Br) 2Br 2(L3) 2] (6), L4 gave the mononuclear complexes [NiCl 2(L4)] (7) and [NiBr 2(L4)] (8). Activation of 1-8 with EtAlCl 2 resulted in the oligomerization of ethylene to C 4, C 6, and C 8 alkenes, followed by subsequent Friedel - Crafts alkylation of the toluene solvent. Activities as high as 15 660 kg of alkylated products/mol Ni/h were observed for 5 at 40 bar. However, when hexane was used as solvent, only trace amounts of alkylated toluene products were observed.

UR - http://www.scopus.com/inward/record.url?scp=65449124331&partnerID=8YFLogxK

U2 - 10.1021/om8006322

DO - 10.1021/om8006322

M3 - Article

AN - SCOPUS:65449124331

SN - 0276-7333

VL - 28

SP - 2127

EP - 2133

JO - Organometallics

JF - Organometallics

IS - 7

ER -

(Pyrazol-l-ylmethyl)pyridine nickel complexes: Ethylene oligomerization and unusual friedel - crafts alkylation catalysts

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this