Synthesis and Reactivity of Phosphinocarbyne Complexes

Annie L. Colebatch; Anthony F. Hill; Manab Sharma

doi:10.1021/om500833n

Synthesis and Reactivity of Phosphinocarbyne Complexes

Annie L. Colebatch, Anthony F. Hill^*, Manab Sharma

^*Corresponding author for this work

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

34 Citations (Scopus)

Abstract

The successive treatment of [W(≡CBr)(CO)₂(Tp∗)] (Tp∗ = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with ⁿBuLi and ClPPh₂ affords the phosphinocarbyne complex [W(≡CPPh₂)(CO)₂(Tp∗)] (1), DFT interrogation of which suggests that reactions with electrophiles may involve both the phosphorus atom and/or the metal-carbon multiple bond. This is borne out in reactions of 1 with a variety of electrophilic reagents. With iodomethane or dimethylsulfide borane, electrophilic attack occurs exclusively at phosphorus to afford the compounds [W(≡CPMePh₂)(CO)₂(Tp∗)]I ([2]I) and [W{≡CP(BH₃)Ph₂}(CO)₂(Tp∗)] (3). The reaction of 1 with sulfur affords both the thiophosphorylcarbyne complex [W{≡CP(=S)Ph₂}(CO)₂(Tp∗)] (4) and the thioacyl complex [W{η²-SCP(=S)Ph₂}(CO)₂(Tp∗)] (5), though 4 fails to react with sulfur to provide 5. In a similar manner, the complexes 2 and 3 also fail to react with sulfur, indicating that increasing the valance of the phosphorus center of 1 deactivates the W≡C bond toward further attack. Addition of selenium to 1 occurs exclusively at phosphorus to afford [W{≡CP(=Se)Ph₂}(CO)₂(Tp∗)] (6) with no indication of selenoacyl formation. Reversible protonation of 1 with HBF₄ in diethyl ether precipitates the phosphoniocarbyne salt [W(≡CPHPh₂)(CO)₂(Tp∗)]BF₄, [8]BF₄, which, however, on dissolution in dichloromethane rearranges irreversibly to the thermodynamic (ΔG_cacld = 22.4 kJmol^-1) phosphinocarbene isomer [W(η²=CHPPh₂)(CO)₂(Tp∗)]BF₄, [9]BF₄.

Original language	English
Pages (from-to)	2165-2182
Number of pages	18
Journal	Organometallics
Volume	34
Issue number	11
DOIs	https://doi.org/10.1021/om500833n
Publication status	Published - 8 Jun 2015

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@article{2183f1164fd9436285adf7978cd56919,

title = "Synthesis and Reactivity of Phosphinocarbyne Complexes",

abstract = "The successive treatment of [W(≡CBr)(CO)2(Tp∗)] (Tp∗ = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with nBuLi and ClPPh2 affords the phosphinocarbyne complex [W(≡CPPh2)(CO)2(Tp∗)] (1), DFT interrogation of which suggests that reactions with electrophiles may involve both the phosphorus atom and/or the metal-carbon multiple bond. This is borne out in reactions of 1 with a variety of electrophilic reagents. With iodomethane or dimethylsulfide borane, electrophilic attack occurs exclusively at phosphorus to afford the compounds [W(≡CPMePh2)(CO)2(Tp∗)]I ([2]I) and [W{≡CP(BH3)Ph2}(CO)2(Tp∗)] (3). The reaction of 1 with sulfur affords both the thiophosphorylcarbyne complex [W{≡CP(=S)Ph2}(CO)2(Tp∗)] (4) and the thioacyl complex [W{η2-SCP(=S)Ph2}(CO)2(Tp∗)] (5), though 4 fails to react with sulfur to provide 5. In a similar manner, the complexes 2 and 3 also fail to react with sulfur, indicating that increasing the valance of the phosphorus center of 1 deactivates the W≡C bond toward further attack. Addition of selenium to 1 occurs exclusively at phosphorus to afford [W{≡CP(=Se)Ph2}(CO)2(Tp∗)] (6) with no indication of selenoacyl formation. Reversible protonation of 1 with HBF4 in diethyl ether precipitates the phosphoniocarbyne salt [W(≡CPHPh2)(CO)2(Tp∗)]BF4, [8]BF4, which, however, on dissolution in dichloromethane rearranges irreversibly to the thermodynamic (ΔGcacld = 22.4 kJmol-1) phosphinocarbene isomer [W(η2=CHPPh2)(CO)2(Tp∗)]BF4, [9]BF4.",

author = "Colebatch, {Annie L.} and Hill, {Anthony F.} and Manab Sharma",

note = "Publisher Copyright: {\textcopyright} Published 2014 by the American Chemical Society.",

year = "2015",

month = jun,

day = "8",

doi = "10.1021/om500833n",

language = "English",

volume = "34",

pages = "2165--2182",

journal = "Organometallics",

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publisher = "American Chemical Society",

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TY - JOUR

T1 - Synthesis and Reactivity of Phosphinocarbyne Complexes

AU - Colebatch, Annie L.

AU - Hill, Anthony F.

AU - Sharma, Manab

PY - 2015/6/8

Y1 - 2015/6/8

N2 - The successive treatment of [W(≡CBr)(CO)2(Tp∗)] (Tp∗ = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with nBuLi and ClPPh2 affords the phosphinocarbyne complex [W(≡CPPh2)(CO)2(Tp∗)] (1), DFT interrogation of which suggests that reactions with electrophiles may involve both the phosphorus atom and/or the metal-carbon multiple bond. This is borne out in reactions of 1 with a variety of electrophilic reagents. With iodomethane or dimethylsulfide borane, electrophilic attack occurs exclusively at phosphorus to afford the compounds [W(≡CPMePh2)(CO)2(Tp∗)]I ([2]I) and [W{≡CP(BH3)Ph2}(CO)2(Tp∗)] (3). The reaction of 1 with sulfur affords both the thiophosphorylcarbyne complex [W{≡CP(=S)Ph2}(CO)2(Tp∗)] (4) and the thioacyl complex [W{η2-SCP(=S)Ph2}(CO)2(Tp∗)] (5), though 4 fails to react with sulfur to provide 5. In a similar manner, the complexes 2 and 3 also fail to react with sulfur, indicating that increasing the valance of the phosphorus center of 1 deactivates the W≡C bond toward further attack. Addition of selenium to 1 occurs exclusively at phosphorus to afford [W{≡CP(=Se)Ph2}(CO)2(Tp∗)] (6) with no indication of selenoacyl formation. Reversible protonation of 1 with HBF4 in diethyl ether precipitates the phosphoniocarbyne salt [W(≡CPHPh2)(CO)2(Tp∗)]BF4, [8]BF4, which, however, on dissolution in dichloromethane rearranges irreversibly to the thermodynamic (ΔGcacld = 22.4 kJmol-1) phosphinocarbene isomer [W(η2=CHPPh2)(CO)2(Tp∗)]BF4, [9]BF4.

AB - The successive treatment of [W(≡CBr)(CO)2(Tp∗)] (Tp∗ = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with nBuLi and ClPPh2 affords the phosphinocarbyne complex [W(≡CPPh2)(CO)2(Tp∗)] (1), DFT interrogation of which suggests that reactions with electrophiles may involve both the phosphorus atom and/or the metal-carbon multiple bond. This is borne out in reactions of 1 with a variety of electrophilic reagents. With iodomethane or dimethylsulfide borane, electrophilic attack occurs exclusively at phosphorus to afford the compounds [W(≡CPMePh2)(CO)2(Tp∗)]I ([2]I) and [W{≡CP(BH3)Ph2}(CO)2(Tp∗)] (3). The reaction of 1 with sulfur affords both the thiophosphorylcarbyne complex [W{≡CP(=S)Ph2}(CO)2(Tp∗)] (4) and the thioacyl complex [W{η2-SCP(=S)Ph2}(CO)2(Tp∗)] (5), though 4 fails to react with sulfur to provide 5. In a similar manner, the complexes 2 and 3 also fail to react with sulfur, indicating that increasing the valance of the phosphorus center of 1 deactivates the W≡C bond toward further attack. Addition of selenium to 1 occurs exclusively at phosphorus to afford [W{≡CP(=Se)Ph2}(CO)2(Tp∗)] (6) with no indication of selenoacyl formation. Reversible protonation of 1 with HBF4 in diethyl ether precipitates the phosphoniocarbyne salt [W(≡CPHPh2)(CO)2(Tp∗)]BF4, [8]BF4, which, however, on dissolution in dichloromethane rearranges irreversibly to the thermodynamic (ΔGcacld = 22.4 kJmol-1) phosphinocarbene isomer [W(η2=CHPPh2)(CO)2(Tp∗)]BF4, [9]BF4.

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U2 - 10.1021/om500833n

DO - 10.1021/om500833n

M3 - Article

SN - 0276-7333

VL - 34

SP - 2165

EP - 2182

JO - Organometallics

JF - Organometallics

IS - 11

ER -

Synthesis and Reactivity of Phosphinocarbyne Complexes

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