Exclusive C-C activation and an apparent α-H elimination with a rhodium phosphinite pincer complex

Hiyam Salem, Yehoshoa Ben-David, Linda J W Shimon, David Milstein

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

Exclusive C-C bond activation involving the new bisphosphinite ligand {C6H3(CH3)[OP(iPr)2] 2} (1) was observed at room temperature, upon reaction with the cationic complex [Rh(COE)2(THF)2]BF4 (COE = cyclooctene) in THF, yielding the Rh(III) complex [(POCOP)Rh(Me)]BF4 (2) (POCOP = C6H3[OP(iPr)2] 2). No parallel C-H activation was observed. This preference is assumed to be governed by the better directed phosphinite-bound metal center toward the C-C bond. A single-crystal X-ray diffraction analysis of complex 2 revealed a square pyramidal geometry with the BF4 - ion coordinated to the metal center. Complex 2 reacted with H2 at room temperature in THF to yield the Rh(III)-hydrido complex 3 and methane. Deprotonation of 3 with KOtBu yielded the Rh(I) dinitrogen complex [(POCOP)Rh]2(μ-N2) (4), which upon reaction with 1 equiv of CO or ethylene formed (POCOP)Rh(CO) (5) or (POCOP)Rh-(C 2H4) (6), respectively. Complex 4 readily underwent oxidative addition of Mel, benzyl chloride, and benzyl bromide, forming complexes 7, 8, and 9, respectively. Halide abstraction from complex 9 with AgBF4 led to the cationic benzyl complex 12, bearing a coordinated BF4 - ion as observed by a single-crystal X-ray diffraction analysis. Finally, we report an apparent α-H elimination from Rh(III)-Me, which takes place upon heating of the C-C activation product 2 at 150°C in the solid state, yielding the hydride complex 3 and ethylene.

Original languageEnglish
Pages (from-to)2292-2300
Number of pages9
JournalOrganometallics
Volume25
Issue number9
DOIs
Publication statusPublished - Apr 24 2006

Fingerprint

Rhodium
rhodium
elimination
Chemical activation
activation
Carbon Monoxide
X ray diffraction analysis
ethylene
Bearings (structural)
Metals
Single crystals
Ions
Deprotonation
single crystals
Methane
room temperature
diffraction
Hydrides
metals
hydrides

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Organic Chemistry

Cite this

Exclusive C-C activation and an apparent α-H elimination with a rhodium phosphinite pincer complex. / Salem, Hiyam; Ben-David, Yehoshoa; Shimon, Linda J W; Milstein, David.

In: Organometallics, Vol. 25, No. 9, 24.04.2006, p. 2292-2300.

Research output: Contribution to journalArticle

Salem, Hiyam ; Ben-David, Yehoshoa ; Shimon, Linda J W ; Milstein, David. / Exclusive C-C activation and an apparent α-H elimination with a rhodium phosphinite pincer complex. In: Organometallics. 2006 ; Vol. 25, No. 9. pp. 2292-2300.
@article{18ade0ad2da64ef7bff4ec71268cd6ce,
title = "Exclusive C-C activation and an apparent α-H elimination with a rhodium phosphinite pincer complex",
abstract = "Exclusive C-C bond activation involving the new bisphosphinite ligand {C6H3(CH3)[OP(iPr)2] 2} (1) was observed at room temperature, upon reaction with the cationic complex [Rh(COE)2(THF)2]BF4 (COE = cyclooctene) in THF, yielding the Rh(III) complex [(POCOP)Rh(Me)]BF4 (2) (POCOP = C6H3[OP(iPr)2] 2). No parallel C-H activation was observed. This preference is assumed to be governed by the better directed phosphinite-bound metal center toward the C-C bond. A single-crystal X-ray diffraction analysis of complex 2 revealed a square pyramidal geometry with the BF4 - ion coordinated to the metal center. Complex 2 reacted with H2 at room temperature in THF to yield the Rh(III)-hydrido complex 3 and methane. Deprotonation of 3 with KOtBu yielded the Rh(I) dinitrogen complex [(POCOP)Rh]2(μ-N2) (4), which upon reaction with 1 equiv of CO or ethylene formed (POCOP)Rh(CO) (5) or (POCOP)Rh-(C 2H4) (6), respectively. Complex 4 readily underwent oxidative addition of Mel, benzyl chloride, and benzyl bromide, forming complexes 7, 8, and 9, respectively. Halide abstraction from complex 9 with AgBF4 led to the cationic benzyl complex 12, bearing a coordinated BF4 - ion as observed by a single-crystal X-ray diffraction analysis. Finally, we report an apparent α-H elimination from Rh(III)-Me, which takes place upon heating of the C-C activation product 2 at 150°C in the solid state, yielding the hydride complex 3 and ethylene.",
author = "Hiyam Salem and Yehoshoa Ben-David and Shimon, {Linda J W} and David Milstein",
year = "2006",
month = "4",
day = "24",
doi = "10.1021/om060005q",
language = "English",
volume = "25",
pages = "2292--2300",
journal = "Organometallics",
issn = "0276-7333",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Exclusive C-C activation and an apparent α-H elimination with a rhodium phosphinite pincer complex

AU - Salem, Hiyam

AU - Ben-David, Yehoshoa

AU - Shimon, Linda J W

AU - Milstein, David

PY - 2006/4/24

Y1 - 2006/4/24

N2 - Exclusive C-C bond activation involving the new bisphosphinite ligand {C6H3(CH3)[OP(iPr)2] 2} (1) was observed at room temperature, upon reaction with the cationic complex [Rh(COE)2(THF)2]BF4 (COE = cyclooctene) in THF, yielding the Rh(III) complex [(POCOP)Rh(Me)]BF4 (2) (POCOP = C6H3[OP(iPr)2] 2). No parallel C-H activation was observed. This preference is assumed to be governed by the better directed phosphinite-bound metal center toward the C-C bond. A single-crystal X-ray diffraction analysis of complex 2 revealed a square pyramidal geometry with the BF4 - ion coordinated to the metal center. Complex 2 reacted with H2 at room temperature in THF to yield the Rh(III)-hydrido complex 3 and methane. Deprotonation of 3 with KOtBu yielded the Rh(I) dinitrogen complex [(POCOP)Rh]2(μ-N2) (4), which upon reaction with 1 equiv of CO or ethylene formed (POCOP)Rh(CO) (5) or (POCOP)Rh-(C 2H4) (6), respectively. Complex 4 readily underwent oxidative addition of Mel, benzyl chloride, and benzyl bromide, forming complexes 7, 8, and 9, respectively. Halide abstraction from complex 9 with AgBF4 led to the cationic benzyl complex 12, bearing a coordinated BF4 - ion as observed by a single-crystal X-ray diffraction analysis. Finally, we report an apparent α-H elimination from Rh(III)-Me, which takes place upon heating of the C-C activation product 2 at 150°C in the solid state, yielding the hydride complex 3 and ethylene.

AB - Exclusive C-C bond activation involving the new bisphosphinite ligand {C6H3(CH3)[OP(iPr)2] 2} (1) was observed at room temperature, upon reaction with the cationic complex [Rh(COE)2(THF)2]BF4 (COE = cyclooctene) in THF, yielding the Rh(III) complex [(POCOP)Rh(Me)]BF4 (2) (POCOP = C6H3[OP(iPr)2] 2). No parallel C-H activation was observed. This preference is assumed to be governed by the better directed phosphinite-bound metal center toward the C-C bond. A single-crystal X-ray diffraction analysis of complex 2 revealed a square pyramidal geometry with the BF4 - ion coordinated to the metal center. Complex 2 reacted with H2 at room temperature in THF to yield the Rh(III)-hydrido complex 3 and methane. Deprotonation of 3 with KOtBu yielded the Rh(I) dinitrogen complex [(POCOP)Rh]2(μ-N2) (4), which upon reaction with 1 equiv of CO or ethylene formed (POCOP)Rh(CO) (5) or (POCOP)Rh-(C 2H4) (6), respectively. Complex 4 readily underwent oxidative addition of Mel, benzyl chloride, and benzyl bromide, forming complexes 7, 8, and 9, respectively. Halide abstraction from complex 9 with AgBF4 led to the cationic benzyl complex 12, bearing a coordinated BF4 - ion as observed by a single-crystal X-ray diffraction analysis. Finally, we report an apparent α-H elimination from Rh(III)-Me, which takes place upon heating of the C-C activation product 2 at 150°C in the solid state, yielding the hydride complex 3 and ethylene.

UR - http://www.scopus.com/inward/record.url?scp=33646440151&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646440151&partnerID=8YFLogxK

U2 - 10.1021/om060005q

DO - 10.1021/om060005q

M3 - Article

AN - SCOPUS:33646440151

VL - 25

SP - 2292

EP - 2300

JO - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 9

ER -