Reactions of bis(iminophosphoranes) with palladium(II) dichloride: Metal-induced tautomerization orthopalladation and unexpected platinum-assisted [2 + 2] cycloaddition of an aryl-nitrile with a phosphinimine moiety

Mandy W. Avis, Milko van der Boom, Cornelis J. Elsevier, Wilberth J J Smeets, Anthony L. Spek

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Abstract

Reactions of bis(iminophosphoranyl)methane, CH2(PPh2=N-aryl)2, (BIPM; 1a,b) or 1,1-bis(iminophosphoranyl)ethane (1,1-BIPE; 1c) with Pd-and Pt-dichlorides containing weakly coordinating ligands (L) such as nitriles or cyclo-octadiene, afforded several products depending on the reaction time, type of ligand (1a-c) or nature of the metal. The first reaction observed is a metal-assisted tautomerization of BIPM to aryl-N=PPh2-CH=PPh2-NH-aryl. When BIPM reacts with PdCl2(L)2, exclusive formation of the C,N-chelate PdCl2{CH(PPh2=N-aryl)(PPh2-NH-aryl)} (2a,b) is observed, whereas with 1,1-BIPE (1c) a product mixture consisting of a C,N-chelate (2c) and an N,N′-chelate (3) is found. Orthometallation of the four-membered palladacycle (2) took place upon heating, giving the five-membered palladacycle [PdCl2{2-C6H4-PPh(NH[-pTol)-C′H-PPh2(NH-pTol)}-C,C′] (4). The molecular structure of 4 has been determined by X-ray crystallography. Reactions of BIPM (1a,b) with PtCl2(RC≡N)2 (R = phenyl, p-tolyl) afforded entirely different products: the six-membered platinacycles [PtCl(RC≡N){aryl-N=C(R)-N=PPh2-CH=PPb2-NH-aryl}-C,N]Cl (5) and [PtCl2{aryl-N=C(R)-N=PPh2-CH=PPh2-NH-aryl}-C,N] (6), due to an unexpected 2 + 2 cycloaddition of a nitrile with a P=N group.

Original languageEnglish
Pages (from-to)263-276
Number of pages14
JournalJournal of Organometallic Chemistry
Volume527
Issue number1-2
Publication statusPublished - Jan 11 1997

Fingerprint

Nitriles
Cycloaddition
dichlorides
nitriles
Cycloaddition Reaction
Palladium
cycloaddition
Platinum
palladium
platinum
Metals
Ligands
methylidyne
chelates
X ray crystallography
Ethane
metals
Molecular structure
Methane
X Ray Crystallography

Keywords

  • 2 + 2 cycloadditions
  • Nitriles
  • Palladium
  • Phosphinimines
  • Platinum

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry
  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

@article{1583b780b19c40dca1715c5ed9bc1167,
title = "Reactions of bis(iminophosphoranes) with palladium(II) dichloride: Metal-induced tautomerization orthopalladation and unexpected platinum-assisted [2 + 2] cycloaddition of an aryl-nitrile with a phosphinimine moiety",
abstract = "Reactions of bis(iminophosphoranyl)methane, CH2(PPh2=N-aryl)2, (BIPM; 1a,b) or 1,1-bis(iminophosphoranyl)ethane (1,1-BIPE; 1c) with Pd-and Pt-dichlorides containing weakly coordinating ligands (L) such as nitriles or cyclo-octadiene, afforded several products depending on the reaction time, type of ligand (1a-c) or nature of the metal. The first reaction observed is a metal-assisted tautomerization of BIPM to aryl-N=PPh2-CH=PPh2-NH-aryl. When BIPM reacts with PdCl2(L)2, exclusive formation of the C,N-chelate PdCl2{CH(PPh2=N-aryl)(PPh2-NH-aryl)} (2a,b) is observed, whereas with 1,1-BIPE (1c) a product mixture consisting of a C,N-chelate (2c) and an N,N′-chelate (3) is found. Orthometallation of the four-membered palladacycle (2) took place upon heating, giving the five-membered palladacycle [PdCl2{2-C6H4-PPh(NH[-pTol)-C′H-PPh2(NH-pTol)}-C,C′] (4). The molecular structure of 4 has been determined by X-ray crystallography. Reactions of BIPM (1a,b) with PtCl2(RC≡N)2 (R = phenyl, p-tolyl) afforded entirely different products: the six-membered platinacycles [PtCl(RC≡N){aryl-N=C(R)-N=PPh2-CH=PPb2-NH-aryl}-C,N]Cl (5) and [PtCl2{aryl-N=C(R)-N=PPh2-CH=PPh2-NH-aryl}-C,N] (6), due to an unexpected 2 + 2 cycloaddition of a nitrile with a P=N group.",
keywords = "2 + 2 cycloadditions, Nitriles, Palladium, Phosphinimines, Platinum",
author = "Avis, {Mandy W.} and {van der Boom}, Milko and Elsevier, {Cornelis J.} and Smeets, {Wilberth J J} and Spek, {Anthony L.}",
year = "1997",
month = "1",
day = "11",
language = "English",
volume = "527",
pages = "263--276",
journal = "Journal of Organometallic Chemistry",
issn = "0022-328X",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Reactions of bis(iminophosphoranes) with palladium(II) dichloride

T2 - Metal-induced tautomerization orthopalladation and unexpected platinum-assisted [2 + 2] cycloaddition of an aryl-nitrile with a phosphinimine moiety

AU - Avis, Mandy W.

AU - van der Boom, Milko

AU - Elsevier, Cornelis J.

AU - Smeets, Wilberth J J

AU - Spek, Anthony L.

PY - 1997/1/11

Y1 - 1997/1/11

N2 - Reactions of bis(iminophosphoranyl)methane, CH2(PPh2=N-aryl)2, (BIPM; 1a,b) or 1,1-bis(iminophosphoranyl)ethane (1,1-BIPE; 1c) with Pd-and Pt-dichlorides containing weakly coordinating ligands (L) such as nitriles or cyclo-octadiene, afforded several products depending on the reaction time, type of ligand (1a-c) or nature of the metal. The first reaction observed is a metal-assisted tautomerization of BIPM to aryl-N=PPh2-CH=PPh2-NH-aryl. When BIPM reacts with PdCl2(L)2, exclusive formation of the C,N-chelate PdCl2{CH(PPh2=N-aryl)(PPh2-NH-aryl)} (2a,b) is observed, whereas with 1,1-BIPE (1c) a product mixture consisting of a C,N-chelate (2c) and an N,N′-chelate (3) is found. Orthometallation of the four-membered palladacycle (2) took place upon heating, giving the five-membered palladacycle [PdCl2{2-C6H4-PPh(NH[-pTol)-C′H-PPh2(NH-pTol)}-C,C′] (4). The molecular structure of 4 has been determined by X-ray crystallography. Reactions of BIPM (1a,b) with PtCl2(RC≡N)2 (R = phenyl, p-tolyl) afforded entirely different products: the six-membered platinacycles [PtCl(RC≡N){aryl-N=C(R)-N=PPh2-CH=PPb2-NH-aryl}-C,N]Cl (5) and [PtCl2{aryl-N=C(R)-N=PPh2-CH=PPh2-NH-aryl}-C,N] (6), due to an unexpected 2 + 2 cycloaddition of a nitrile with a P=N group.

AB - Reactions of bis(iminophosphoranyl)methane, CH2(PPh2=N-aryl)2, (BIPM; 1a,b) or 1,1-bis(iminophosphoranyl)ethane (1,1-BIPE; 1c) with Pd-and Pt-dichlorides containing weakly coordinating ligands (L) such as nitriles or cyclo-octadiene, afforded several products depending on the reaction time, type of ligand (1a-c) or nature of the metal. The first reaction observed is a metal-assisted tautomerization of BIPM to aryl-N=PPh2-CH=PPh2-NH-aryl. When BIPM reacts with PdCl2(L)2, exclusive formation of the C,N-chelate PdCl2{CH(PPh2=N-aryl)(PPh2-NH-aryl)} (2a,b) is observed, whereas with 1,1-BIPE (1c) a product mixture consisting of a C,N-chelate (2c) and an N,N′-chelate (3) is found. Orthometallation of the four-membered palladacycle (2) took place upon heating, giving the five-membered palladacycle [PdCl2{2-C6H4-PPh(NH[-pTol)-C′H-PPh2(NH-pTol)}-C,C′] (4). The molecular structure of 4 has been determined by X-ray crystallography. Reactions of BIPM (1a,b) with PtCl2(RC≡N)2 (R = phenyl, p-tolyl) afforded entirely different products: the six-membered platinacycles [PtCl(RC≡N){aryl-N=C(R)-N=PPh2-CH=PPb2-NH-aryl}-C,N]Cl (5) and [PtCl2{aryl-N=C(R)-N=PPh2-CH=PPh2-NH-aryl}-C,N] (6), due to an unexpected 2 + 2 cycloaddition of a nitrile with a P=N group.

KW - 2 + 2 cycloadditions

KW - Nitriles

KW - Palladium

KW - Phosphinimines

KW - Platinum

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M3 - Article

AN - SCOPUS:0031564455

VL - 527

SP - 263

EP - 276

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

SN - 0022-328X

IS - 1-2

ER -