The Sensitive Balance between Five-Coordinate Carbene and Six-Coordinate Carbyne Ruthenium Complexes Formed from Ruthenium Vinylidene Precursors
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- 作者：Pablo Gonzá ; lez-Herrero ; Birgit Weberndö ; rfer ; Kerstin Ilg ; Justin Wolf ; and Helmut Werner
- 刊名：Organometallics
- 出版年：2001
- 出版时间：August 20, 2001
- 年：2001
- 卷：20
- 期：17
- 页码：3672 - 3685
- 全文大小：232K
- 年卷期：v.20,no.17(August 20, 2001)
- ISSN：1520-6041
文摘
The reaction of the dichloro(vinylidene)ruthenium compounds [RuCl2(=C=CHR)L2] (R =Ph or tBu and L = PCy3 or PiPr3) (1a-d) with [H(OEt2)2]BArf (BArf- = [B{C6H3(CF3)2-3,5}4]-) resulted in the attack of the proton at the C
carbon atom of the vinylidene ligandand afforded the corresponding cationic, five-coordinate carbyneruthenium complexes [RuCl2(
CCH2R)L2]BArf (2a-d) in almost quantitative yields. The protonation of the carboxylatoderivatives [RuCl(
2-O2CR)(=C=CHPh)(PiPr3)2] [R = H (3a), CH3 (3b), or Ph (3f)] with[H(OEt2)2]BArf led to the formation of the five-coordinate cyclic carbene complexes [RuCl{=C(CH2Ph)OC(O)R}(PiPr3)2]BArf [R = H (6a), CH3 (6b), or Ph (6f)], which are formed vianucleophilic attack of the carboxylato ligand to a cationic carbyneruthenium intermediate.The protonation of the related vinylidene compounds [RuCl(2-O2CR)(=C=CHPh)(PiPr3)2][R = CH2F (3c), CHF2 (3d), CF3 (3e), C6H4NO2-4 (3g), C6H4NO2-2 (3h), C6F5 (3i), and C6H3(NO2)2-2,4 (3j)] with [H(OEt2)2]BArf gave an equilibrium mixture of the carbyne [RuCl(2-O2CR)(CCH2Ph)(PiPr3)2]BArf (5c-e, 5g-j) and the isomeric, cyclic carbene complexes[RuCl{=C(CH2Ph)OC(O)R}(PiPr3)2]BArf (6c-e, 6g-j). The position of this equilibriumsignificantly depends on the basicity of the carboxylato ligand. The six-coordinate cycliccarbene complexes [Ru(2-O2CR1){=C(CH2Ph)OC(O)R2}(PiPr3)2]BArf [R1 = R2 = CHF2 (7a),CF3 (7b); R1 = CF3, R2 = H (7c)] were obtained on protonation of the precursors [Ru(1-O2CR1)(2-O2CR2)(=C=CHPh)(PiPr3)2] (4a-c) with [H(OEt2)2]BArf. Both 7a and 7b undergoa fluxional process in solution resulting in a 1/2 interconversion of the carboxylato groups.The crystal and molecular structures of 2b, 5e, and 6a were determined by X-raycrystallography.
carbon atom of the vinylidene ligandand afforded the corresponding cationic, five-coordinate carbyneruthenium complexes [RuCl2(CCH2R)L2]BArf (2a-d) in almost quantitative yields. The protonation of the carboxylatoderivatives [RuCl(2-O2CR)(=C=CHPh)(PiPr3)2] [R = H (3a), CH3 (3b), or Ph (3f)] with[H(OEt2)2]BArf led to the formation of the five-coordinate cyclic carbene complexes [RuCl{=C(CH2Ph)OC(O)R}(PiPr3)2]BArf [R = H (6a), CH3 (6b), or Ph (6f)], which are formed vianucleophilic attack of the carboxylato ligand to a cationic carbyneruthenium intermediate.The protonation of the related vinylidene compounds [RuCl(2-O2CR)(=C=CHPh)(PiPr3)2][R = CH2F (3c), CHF2 (3d), CF3 (3e), C6H4NO2-4 (3g), C6H4NO2-2 (3h), C6F5 (3i), and C6H3(NO2)2-2,4 (3j)] with [H(OEt2)2]BArf gave an equilibrium mixture of the carbyne [RuCl(2-O2CR)(CCH2Ph)(PiPr3)2]BArf (5c-e, 5g-j) and the isomeric, cyclic carbene complexes[RuCl{=C(CH2Ph)OC(O)R}(PiPr3)2]BArf (6c-e, 6g-j). The position of this equilibriumsignificantly depends on the basicity of the carboxylato ligand. The six-coordinate cycliccarbene complexes [Ru(2-O2CR1){=C(CH2Ph)OC(O)R2}(PiPr3)2]BArf [R1 = R2 = CHF2 (7a),CF3 (7b); R1 = CF3, R2 = H (7c)] were obtained on protonation of the precursors [Ru(1-O2CR1)(2-O2CR2)(=C=CHPh)(PiPr3)2] (4a-c) with [H(OEt2)2]BArf. Both 7a and 7b undergoa fluxional process in solution resulting in a 1/2 interconversion of the carboxylato groups.The crystal and molecular structures of 2b, 5e, and 6a were determined by X-raycrystallography.