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 language | English |
|---|---|
| Pages (from-to) | 2292-2300 |
| Number of pages | 9 |
| Journal | Organometallics |
| Volume | 25 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Apr 24 2006 |
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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 journal › Article
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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.
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U2 - 10.1021/om060005q
DO - 10.1021/om060005q
M3 - Article
VL - 25
SP - 2292
EP - 2300
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 9
ER -