Palladium(II) Chloride Complexes of N,N′-Disubstituted Imidazole-2-thiones

Syntheses, Structures, and Catalytic Performances in Suzuki-Miyaura and Sonogashira Coupling Reactions

Li Ming Zhang, Hai Yan Li, Hong Xi Li, David James Young, Yong Wang, Jian Ping Lang

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Reactions of PdCl2 with 2 equiv of N,N′-disubstituted-imidazole-2-thiones R1R2C3N2S (R1 = R2 = Me (1a), iPr (1b), Cy (1c), C6Me3H2 (1d); R1 = Me, R2 = Ph (1e)) under the different conditions afford five mononuclear complexes trans-[(R1R2C3N2S)2PdCl2] (R1 = R2 = Me (2a), iPr (2b), Cy (2c), C6Me3H2 (2d); R1 = Me, R2 = Ph (2e)) and five binuclear Pd(II) complexes [(PdCl2){μ-(R1R2C3N2S)}]2 (R1 = R2 = Me (3a), iPr (3b), Cy (3c), C6Me3H2 (3d); R1 = Me, R2 = Ph (3e)), respectively. Complexes 2a-2e are easily converted into the corresponding 3a-3e by adding equimolar PdCl2 in refluxing MeOH, while the reverse reaction is achieved at room temperature by addition of 2 equiv of 1a-1e. In 2b, 2d, and 2e, each Pd(II) holds a distorted square planar geometry completed by two trans Cl atoms and two trans S atoms. Complexes 3a-3e have a dimeric [Pd2S2] structure in which two {PdCl2} units are interlinked by two N,N′-disubstituted-imidazole-2-thiones. Each Pd(II) adopts a distorted square planar geometry accomplished by two cis Cl atoms and two cis bridging S atoms. Among them, complex 3d has the two largest C6Me3H2 groups on the 2 and 5 positions of imidazole-2-thione, the longest Pd-μ-S bond, the largest S-Pd-S angle, and displays the highest catalytic activity toward Suzuki-Miyaura and copper-free Sonogashira cross-coupling reactions, which are confirmed by density functional theory calculations. The results provide an interesting insight into the introduction of various substituent groups into the periphery ligands of coordination complex-based catalysts, which could tune their geometric structures to acquire the best catalytic activity toward organic reactions.

Original languageEnglish
Pages (from-to)11230-11243
Number of pages14
JournalInorganic Chemistry
Volume56
Issue number18
DOIs
Publication statusPublished - 18 Sep 2017
Externally publishedYes

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Thiones
Palladium
imidazoles
Chlorides
palladium
chlorides
Atoms
synthesis
atoms
catalytic activity
Catalyst activity
Geometry
Coordination Complexes
cross coupling
geometry
Density functional theory
Copper
density functional theory
Ligands
catalysts

Cite this

@article{226e9e5e57dd46ea88bd1d8d02622c8c,
title = "Palladium(II) Chloride Complexes of N,N′-Disubstituted Imidazole-2-thiones: Syntheses, Structures, and Catalytic Performances in Suzuki-Miyaura and Sonogashira Coupling Reactions",
abstract = "Reactions of PdCl2 with 2 equiv of N,N′-disubstituted-imidazole-2-thiones R1R2C3N2S (R1 = R2 = Me (1a), iPr (1b), Cy (1c), C6Me3H2 (1d); R1 = Me, R2 = Ph (1e)) under the different conditions afford five mononuclear complexes trans-[(R1R2C3N2S)2PdCl2] (R1 = R2 = Me (2a), iPr (2b), Cy (2c), C6Me3H2 (2d); R1 = Me, R2 = Ph (2e)) and five binuclear Pd(II) complexes [(PdCl2){μ-(R1R2C3N2S)}]2 (R1 = R2 = Me (3a), iPr (3b), Cy (3c), C6Me3H2 (3d); R1 = Me, R2 = Ph (3e)), respectively. Complexes 2a-2e are easily converted into the corresponding 3a-3e by adding equimolar PdCl2 in refluxing MeOH, while the reverse reaction is achieved at room temperature by addition of 2 equiv of 1a-1e. In 2b, 2d, and 2e, each Pd(II) holds a distorted square planar geometry completed by two trans Cl atoms and two trans S atoms. Complexes 3a-3e have a dimeric [Pd2S2] structure in which two {PdCl2} units are interlinked by two N,N′-disubstituted-imidazole-2-thiones. Each Pd(II) adopts a distorted square planar geometry accomplished by two cis Cl atoms and two cis bridging S atoms. Among them, complex 3d has the two largest C6Me3H2 groups on the 2 and 5 positions of imidazole-2-thione, the longest Pd-μ-S bond, the largest S-Pd-S angle, and displays the highest catalytic activity toward Suzuki-Miyaura and copper-free Sonogashira cross-coupling reactions, which are confirmed by density functional theory calculations. The results provide an interesting insight into the introduction of various substituent groups into the periphery ligands of coordination complex-based catalysts, which could tune their geometric structures to acquire the best catalytic activity toward organic reactions.",
author = "Zhang, {Li Ming} and Li, {Hai Yan} and Li, {Hong Xi} and Young, {David James} and Yong Wang and Lang, {Jian Ping}",
year = "2017",
month = "9",
day = "18",
doi = "10.1021/acs.inorgchem.7b01616",
language = "English",
volume = "56",
pages = "11230--11243",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "18",

}

Palladium(II) Chloride Complexes of N,N′-Disubstituted Imidazole-2-thiones : Syntheses, Structures, and Catalytic Performances in Suzuki-Miyaura and Sonogashira Coupling Reactions. / Zhang, Li Ming; Li, Hai Yan; Li, Hong Xi; Young, David James; Wang, Yong; Lang, Jian Ping.

In: Inorganic Chemistry, Vol. 56, No. 18, 18.09.2017, p. 11230-11243.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Palladium(II) Chloride Complexes of N,N′-Disubstituted Imidazole-2-thiones

T2 - Syntheses, Structures, and Catalytic Performances in Suzuki-Miyaura and Sonogashira Coupling Reactions

AU - Zhang, Li Ming

AU - Li, Hai Yan

AU - Li, Hong Xi

AU - Young, David James

AU - Wang, Yong

AU - Lang, Jian Ping

PY - 2017/9/18

Y1 - 2017/9/18

N2 - Reactions of PdCl2 with 2 equiv of N,N′-disubstituted-imidazole-2-thiones R1R2C3N2S (R1 = R2 = Me (1a), iPr (1b), Cy (1c), C6Me3H2 (1d); R1 = Me, R2 = Ph (1e)) under the different conditions afford five mononuclear complexes trans-[(R1R2C3N2S)2PdCl2] (R1 = R2 = Me (2a), iPr (2b), Cy (2c), C6Me3H2 (2d); R1 = Me, R2 = Ph (2e)) and five binuclear Pd(II) complexes [(PdCl2){μ-(R1R2C3N2S)}]2 (R1 = R2 = Me (3a), iPr (3b), Cy (3c), C6Me3H2 (3d); R1 = Me, R2 = Ph (3e)), respectively. Complexes 2a-2e are easily converted into the corresponding 3a-3e by adding equimolar PdCl2 in refluxing MeOH, while the reverse reaction is achieved at room temperature by addition of 2 equiv of 1a-1e. In 2b, 2d, and 2e, each Pd(II) holds a distorted square planar geometry completed by two trans Cl atoms and two trans S atoms. Complexes 3a-3e have a dimeric [Pd2S2] structure in which two {PdCl2} units are interlinked by two N,N′-disubstituted-imidazole-2-thiones. Each Pd(II) adopts a distorted square planar geometry accomplished by two cis Cl atoms and two cis bridging S atoms. Among them, complex 3d has the two largest C6Me3H2 groups on the 2 and 5 positions of imidazole-2-thione, the longest Pd-μ-S bond, the largest S-Pd-S angle, and displays the highest catalytic activity toward Suzuki-Miyaura and copper-free Sonogashira cross-coupling reactions, which are confirmed by density functional theory calculations. The results provide an interesting insight into the introduction of various substituent groups into the periphery ligands of coordination complex-based catalysts, which could tune their geometric structures to acquire the best catalytic activity toward organic reactions.

AB - Reactions of PdCl2 with 2 equiv of N,N′-disubstituted-imidazole-2-thiones R1R2C3N2S (R1 = R2 = Me (1a), iPr (1b), Cy (1c), C6Me3H2 (1d); R1 = Me, R2 = Ph (1e)) under the different conditions afford five mononuclear complexes trans-[(R1R2C3N2S)2PdCl2] (R1 = R2 = Me (2a), iPr (2b), Cy (2c), C6Me3H2 (2d); R1 = Me, R2 = Ph (2e)) and five binuclear Pd(II) complexes [(PdCl2){μ-(R1R2C3N2S)}]2 (R1 = R2 = Me (3a), iPr (3b), Cy (3c), C6Me3H2 (3d); R1 = Me, R2 = Ph (3e)), respectively. Complexes 2a-2e are easily converted into the corresponding 3a-3e by adding equimolar PdCl2 in refluxing MeOH, while the reverse reaction is achieved at room temperature by addition of 2 equiv of 1a-1e. In 2b, 2d, and 2e, each Pd(II) holds a distorted square planar geometry completed by two trans Cl atoms and two trans S atoms. Complexes 3a-3e have a dimeric [Pd2S2] structure in which two {PdCl2} units are interlinked by two N,N′-disubstituted-imidazole-2-thiones. Each Pd(II) adopts a distorted square planar geometry accomplished by two cis Cl atoms and two cis bridging S atoms. Among them, complex 3d has the two largest C6Me3H2 groups on the 2 and 5 positions of imidazole-2-thione, the longest Pd-μ-S bond, the largest S-Pd-S angle, and displays the highest catalytic activity toward Suzuki-Miyaura and copper-free Sonogashira cross-coupling reactions, which are confirmed by density functional theory calculations. The results provide an interesting insight into the introduction of various substituent groups into the periphery ligands of coordination complex-based catalysts, which could tune their geometric structures to acquire the best catalytic activity toward organic reactions.

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U2 - 10.1021/acs.inorgchem.7b01616

DO - 10.1021/acs.inorgchem.7b01616

M3 - Article

VL - 56

SP - 11230

EP - 11243

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 18

ER -