Dimethylphosphinate bridged binuclear Rh(i) catalysts for the alkoxycarbonylation of aromatic C-H bonds

Amaia Iturmendi; Pablo J. Sanz Miguel; Saheed A. Popoola; Abdulaziz A. Al-Saadi; Manuel Iglesias; Luis A. Oro

doi:10.1039/c6dt03010f

Dimethylphosphinate bridged binuclear Rh(i) catalysts for the alkoxycarbonylation of aromatic C-H bonds

Amaia Iturmendi
, Pablo J. Sanz Miguel
, Saheed A. Popoola
, Abdulaziz A. Al-Saadi
, Manuel Iglesias^*
, Luis A. Oro

^*Corresponding author for this work

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

5 Scopus citations

Abstract

A variety of binuclear rhodium(i) complexes featuring two bridging dimethylphosphinate ligands ((CH₃)₂PO₂^-) have been prepared and tested in the alkoxycarbonylation of aromatic C-H bonds. The complex [Rh(μ-κO,O′-(CH₃)₂PO₂)(cod)]₂ has been prepared by a reaction of [Rh(μ-MeO)(cod)]₂ with 2 equivalents of dimethylphosphinic acid. Binuclear complexes [Rh(μ-κO,O′-(CH₃)₂PO₂)(CO)L]₂ (L = PPh₃, P(OMe)Ph₂ and P(OPh)₃) were obtained by carbonylation of the related mononuclear complexes [Rh(κO-(CH₃)₂PO₂)(cod)(L)], which were prepared in situ by the reaction of [Rh(μ-κO,O′-(CH₃)₂PO₂)(cod)]₂ with 2 equivalents of L. Conversely, if L = IPr, the reaction of [Rh(μ-κO,O′-(CH₃)₂PO₂)(CO)L]₂ with carbon monoxide affords the mononuclear complex [Rh(κO-(CH₃)₂PO₂)(CO)₂IPr]. The subsequent reaction with trimethylamine N-oxide gives the corresponding binuclear complex [Rh(μ-κO,O′-(CH₃)₂PO₂)(CO)(IPr)]₂ by abstraction of one of the carbonyl ligands. Complexes [Rh(μ-κO,O′-(CH₃)₂PO₂)(cod)]₂ and [Rh(κO-(CH₃)₂PO₂)(cod)(L)] (L = IPr, PPh₃, P(OMe)Ph₂, P(OPh)₃) are active precatalysts in the alkoxycarbonylation of C-H bonds, with the ligand system playing a key role in the catalytic activity. The complexes that feature more labile Rh-L bonds give rise to better catalysts, probably due to the more straightforward substitution of L by a second carbonyl ligand, since a more electrophilic carbonyl carbon atom is more susceptible toward aryl migration. In fact, complexes [Rh(μ-κO,O′-(CH₃)₂PO₂)(CO)₂]₂ and [Rh(μ-Cl)(CO)₂]₂, generated in situ from [Rh(μ-κO,O′-(CH₃)₂PO₂)(cod)]₂ and [Rh(μ-Cl)(cod)₂]₂, respectively, are the most active catalysts tested in this work.

Original language	English
Pages (from-to)	16955-16965
Number of pages	11
Journal	Dalton Transactions
Volume	45
Issue number	42
DOIs	https://doi.org/10.1039/c6dt03010f
State	Published - 2016

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Publisher Copyright:
© 2016 The Royal Society of Chemistry.

ASJC Scopus subject areas

Inorganic Chemistry

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10.1039/c6dt03010f

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@article{6e57db52e8e3401ca73dad962147a0bf,

title = "Dimethylphosphinate bridged binuclear Rh(i) catalysts for the alkoxycarbonylation of aromatic C-H bonds",

abstract = "A variety of binuclear rhodium(i) complexes featuring two bridging dimethylphosphinate ligands ((CH3)2PO2-) have been prepared and tested in the alkoxycarbonylation of aromatic C-H bonds. The complex [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 has been prepared by a reaction of [Rh(μ-MeO)(cod)]2 with 2 equivalents of dimethylphosphinic acid. Binuclear complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 (L = PPh3, P(OMe)Ph2 and P(OPh)3) were obtained by carbonylation of the related mononuclear complexes [Rh(κO-(CH3)2PO2)(cod)(L)], which were prepared in situ by the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 with 2 equivalents of L. Conversely, if L = IPr, the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 with carbon monoxide affords the mononuclear complex [Rh(κO-(CH3)2PO2)(CO)2IPr]. The subsequent reaction with trimethylamine N-oxide gives the corresponding binuclear complex [Rh(μ-κO,O′-(CH3)2PO2)(CO)(IPr)]2 by abstraction of one of the carbonyl ligands. Complexes [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(κO-(CH3)2PO2)(cod)(L)] (L = IPr, PPh3, P(OMe)Ph2, P(OPh)3) are active precatalysts in the alkoxycarbonylation of C-H bonds, with the ligand system playing a key role in the catalytic activity. The complexes that feature more labile Rh-L bonds give rise to better catalysts, probably due to the more straightforward substitution of L by a second carbonyl ligand, since a more electrophilic carbonyl carbon atom is more susceptible toward aryl migration. In fact, complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)2]2 and [Rh(μ-Cl)(CO)2]2, generated in situ from [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(μ-Cl)(cod)2]2, respectively, are the most active catalysts tested in this work.",

author = "Amaia Iturmendi and \{Sanz Miguel\}, \{Pablo J.\} and Popoola, \{Saheed A.\} and Al-Saadi, \{Abdulaziz A.\} and Manuel Iglesias and Oro, \{Luis A.\}",

note = "Publisher Copyright: {\textcopyright} 2016 The Royal Society of Chemistry.",

year = "2016",

doi = "10.1039/c6dt03010f",

language = "English",

volume = "45",

pages = "16955--16965",

journal = "Dalton Transactions",

issn = "1477-9226",

publisher = "Royal Society of Chemistry",

number = "42",

}

TY - JOUR

T1 - Dimethylphosphinate bridged binuclear Rh(i) catalysts for the alkoxycarbonylation of aromatic C-H bonds

AU - Iturmendi, Amaia

AU - Sanz Miguel, Pablo J.

AU - Popoola, Saheed A.

AU - Al-Saadi, Abdulaziz A.

AU - Iglesias, Manuel

AU - Oro, Luis A.

PY - 2016

Y1 - 2016

N2 - A variety of binuclear rhodium(i) complexes featuring two bridging dimethylphosphinate ligands ((CH3)2PO2-) have been prepared and tested in the alkoxycarbonylation of aromatic C-H bonds. The complex [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 has been prepared by a reaction of [Rh(μ-MeO)(cod)]2 with 2 equivalents of dimethylphosphinic acid. Binuclear complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 (L = PPh3, P(OMe)Ph2 and P(OPh)3) were obtained by carbonylation of the related mononuclear complexes [Rh(κO-(CH3)2PO2)(cod)(L)], which were prepared in situ by the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 with 2 equivalents of L. Conversely, if L = IPr, the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 with carbon monoxide affords the mononuclear complex [Rh(κO-(CH3)2PO2)(CO)2IPr]. The subsequent reaction with trimethylamine N-oxide gives the corresponding binuclear complex [Rh(μ-κO,O′-(CH3)2PO2)(CO)(IPr)]2 by abstraction of one of the carbonyl ligands. Complexes [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(κO-(CH3)2PO2)(cod)(L)] (L = IPr, PPh3, P(OMe)Ph2, P(OPh)3) are active precatalysts in the alkoxycarbonylation of C-H bonds, with the ligand system playing a key role in the catalytic activity. The complexes that feature more labile Rh-L bonds give rise to better catalysts, probably due to the more straightforward substitution of L by a second carbonyl ligand, since a more electrophilic carbonyl carbon atom is more susceptible toward aryl migration. In fact, complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)2]2 and [Rh(μ-Cl)(CO)2]2, generated in situ from [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(μ-Cl)(cod)2]2, respectively, are the most active catalysts tested in this work.

AB - A variety of binuclear rhodium(i) complexes featuring two bridging dimethylphosphinate ligands ((CH3)2PO2-) have been prepared and tested in the alkoxycarbonylation of aromatic C-H bonds. The complex [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 has been prepared by a reaction of [Rh(μ-MeO)(cod)]2 with 2 equivalents of dimethylphosphinic acid. Binuclear complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 (L = PPh3, P(OMe)Ph2 and P(OPh)3) were obtained by carbonylation of the related mononuclear complexes [Rh(κO-(CH3)2PO2)(cod)(L)], which were prepared in situ by the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 with 2 equivalents of L. Conversely, if L = IPr, the reaction of [Rh(μ-κO,O′-(CH3)2PO2)(CO)L]2 with carbon monoxide affords the mononuclear complex [Rh(κO-(CH3)2PO2)(CO)2IPr]. The subsequent reaction with trimethylamine N-oxide gives the corresponding binuclear complex [Rh(μ-κO,O′-(CH3)2PO2)(CO)(IPr)]2 by abstraction of one of the carbonyl ligands. Complexes [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(κO-(CH3)2PO2)(cod)(L)] (L = IPr, PPh3, P(OMe)Ph2, P(OPh)3) are active precatalysts in the alkoxycarbonylation of C-H bonds, with the ligand system playing a key role in the catalytic activity. The complexes that feature more labile Rh-L bonds give rise to better catalysts, probably due to the more straightforward substitution of L by a second carbonyl ligand, since a more electrophilic carbonyl carbon atom is more susceptible toward aryl migration. In fact, complexes [Rh(μ-κO,O′-(CH3)2PO2)(CO)2]2 and [Rh(μ-Cl)(CO)2]2, generated in situ from [Rh(μ-κO,O′-(CH3)2PO2)(cod)]2 and [Rh(μ-Cl)(cod)2]2, respectively, are the most active catalysts tested in this work.

UR - https://www.scopus.com/pages/publications/84994000460

U2 - 10.1039/c6dt03010f

DO - 10.1039/c6dt03010f

M3 - Article

AN - SCOPUS:84994000460

SN - 1477-9226

VL - 45

SP - 16955

EP - 16965

JO - Dalton Transactions

JF - Dalton Transactions

IS - 42

ER -

Dimethylphosphinate bridged binuclear Rh(i) catalysts for the alkoxycarbonylation of aromatic C-H bonds

Abstract

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