Abstract
Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl2(L)], the stable nickel product isolated is the ionic [Ni(L)2]Cl2. These NiII complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2 a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl2(dppe)] (dppe = 1,2-bis(diphenylphosphino)ethane), 2a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh 3, and this suggests that the PPh2 functionality of hybrid NHC ligand L can partially take on the role of free PPh3. However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh 3, accelerates the reaction.
| Original language | English |
|---|---|
| Pages (from-to) | 582-591 |
| Number of pages | 10 |
| Journal | Chemistry - A European Journal |
| Volume | 13 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2007 Jan 22 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Organic Chemistry
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Nickel(II) complexes of bidentate N-heterocyclic carbene/phosphine ligands : Efficient catalysts for suzuki coupling of aryl chlorides. / Lee, Chun Chin; Ke, Wei Chi; Chan, Kai Ting; Lai, Chun Liang; Hu, Ching Han; Lee, Hon Man.
In: Chemistry - A European Journal, Vol. 13, No. 2, 22.01.2007, p. 582-591.Research output: Contribution to journal › Article
TY - JOUR
T1 - Nickel(II) complexes of bidentate N-heterocyclic carbene/phosphine ligands
T2 - Efficient catalysts for suzuki coupling of aryl chlorides
AU - Lee, Chun Chin
AU - Ke, Wei Chi
AU - Chan, Kai Ting
AU - Lai, Chun Liang
AU - Hu, Ching Han
AU - Lee, Hon Man
PY - 2007/1/22
Y1 - 2007/1/22
N2 - Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl2(L)], the stable nickel product isolated is the ionic [Ni(L)2]Cl2. These NiII complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2 a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl2(dppe)] (dppe = 1,2-bis(diphenylphosphino)ethane), 2a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh 3, and this suggests that the PPh2 functionality of hybrid NHC ligand L can partially take on the role of free PPh3. However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh 3, accelerates the reaction.
AB - Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl2(L)], the stable nickel product isolated is the ionic [Ni(L)2]Cl2. These NiII complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2 a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl2(dppe)] (dppe = 1,2-bis(diphenylphosphino)ethane), 2a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh 3, and this suggests that the PPh2 functionality of hybrid NHC ligand L can partially take on the role of free PPh3. However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh 3, accelerates the reaction.
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U2 - 10.1002/chem.200600502
DO - 10.1002/chem.200600502
M3 - Article
C2 - 16969780
AN - SCOPUS:33846219583
VL - 13
SP - 582
EP - 591
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 2
ER -