Multiple Re-C Bonds at the [{MeC(CH2PPh2)3}Re(CO)2]+ Auxiliary
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- 作者：Claudio Bianchini ; Andrea Marchi ; Lorenza Marvelli ; Maurizio Peruzzini ; Antonio Romerosa ; and Roberto Rossi
- 刊名：Organometallics
- 出版年：1996
- 出版时间：September 3, 1996
- 年：1996
- 卷：15
- 期：18
- 页码：3804 - 3816
- 全文大小：485K
- 年卷期：v.15,no.18(September 3, 1996)
- ISSN：1520-6041
文摘
After displacement of the 
2-H2 ligandfrom[(triphos)Re(CO)2(2-H2)]BF4(2), ethyne andvarious 1-alkynes, HC
CR, are tautomerized at the Re(I) centerto vinylidene ligands (R =H, Ph, p-tolyl, COOEt,n-C6H13, SiMe3). Akinetic 
-alkyne adduct is intercepted at lowtemperature during the reaction between 2 and ethyne.The primary vinylidene complex[(triphos)Re(CO)2(C=CH2)]BF4(7-BF4) can also be obtained by reaction of the(trimethylsilyl)vinylidene complex[(triphos)Re(CO)2{C=C(H)SiMe3}]BF4with stoichiometric water. Unprecedented examples of addition of either water or alcohols toRe-vinylidene moieties togive hydroxycarbene or alkoxycarbene complexes are presented. Inparticular, an excess ofwater transforms 7-BF4 into the secondaryhydroxycarbene complex[(triphos)Re(CO)2{C(OH)CH3}]BF4 (11), which can beisolated in the solid state. Upon thermolysis inrefluxingtetrahydrofuran, 11 selectively converts to the tricarbonylcomplex[(triphos)Re(CO)3]BF4and methane. Deprotonation of 11 by mild bases givesthe acetyl derivative (triphos)Re(CO)2(COCH3), which regenerates thehydroxycarbene precursor by protonation with strongacids. The ethoxycarbene complexes[(triphos)Re(CO)2{C(OEt)CH2R}]BPh4(R = H, COOEt)are prepared by nucleophilic addition of ethanol across the C=Cdouble bond of thecorresponding vinylidene derivatives. Neutral 
-alkynylcomplexes of the general formula(triphos)Re(CO)2(CCR) (R = Ph,p-tolyl, COOEt, n-C6H13,H) are obtained by reaction ofthe vinylidene derivatives with strong bases. The reaction of the-alkynyl complexes withvarious methylating agents affords disubstituted vinylidenederivatives, herein exemplifiedby[(triphos)Re(CO)2{C=C(Me)Ph}](OSO2CF3).The structural identities in the solid stateof the phenylvinylidene complex[(triphos)Re(CO)2{C=C(H)Ph}]BF4and of the ethoxycarbenecomplex[(triphos)Re(CO)2{C(OEt)CH3}]BPh4have been determined by X-ray diffractionanalyses. In both complexes the metal center is octahedrallycoordinated by a fac triphosligand, by two mutually cis terminal carbonyls, and by theorganyl ligand.
2-H2 ligandfrom[(triphos)Re(CO)2(2-H2)]BF4(2), ethyne andvarious 1-alkynes, HCCR, are tautomerized at the Re(I) centerto vinylidene ligands (R =H, Ph, p-tolyl, COOEt,n-C6H13, SiMe3). Akinetic -alkyne adduct is intercepted at lowtemperature during the reaction between 2 and ethyne.The primary vinylidene complex[(triphos)Re(CO)2(C=CH2)]BF4(7-BF4) can also be obtained by reaction of the(trimethylsilyl)vinylidene complex[(triphos)Re(CO)2{C=C(H)SiMe3}]BF4with stoichiometric water. Unprecedented examples of addition of either water or alcohols toRe-vinylidene moieties togive hydroxycarbene or alkoxycarbene complexes are presented. Inparticular, an excess ofwater transforms 7-BF4 into the secondaryhydroxycarbene complex[(triphos)Re(CO)2{C(OH)CH3}]BF4 (11), which can beisolated in the solid state. Upon thermolysis inrefluxingtetrahydrofuran, 11 selectively converts to the tricarbonylcomplex[(triphos)Re(CO)3]BF4and methane. Deprotonation of 11 by mild bases givesthe acetyl derivative (triphos)Re(CO)2(COCH3), which regenerates thehydroxycarbene precursor by protonation with strongacids. The ethoxycarbene complexes[(triphos)Re(CO)2{C(OEt)CH2R}]BPh4(R = H, COOEt)are prepared by nucleophilic addition of ethanol across the C=Cdouble bond of thecorresponding vinylidene derivatives. Neutral -alkynylcomplexes of the general formula(triphos)Re(CO)2(CCR) (R = Ph,p-tolyl, COOEt, n-C6H13,H) are obtained by reaction ofthe vinylidene derivatives with strong bases. The reaction of the-alkynyl complexes withvarious methylating agents affords disubstituted vinylidenederivatives, herein exemplifiedby[(triphos)Re(CO)2{C=C(Me)Ph}](OSO2CF3).The structural identities in the solid stateof the phenylvinylidene complex[(triphos)Re(CO)2{C=C(H)Ph}]BF4and of the ethoxycarbenecomplex[(triphos)Re(CO)2{C(OEt)CH3}]BPh4have been determined by X-ray diffractionanalyses. In both complexes the metal center is octahedrallycoordinated by a fac triphosligand, by two mutually cis terminal carbonyls, and by theorganyl ligand.