Chemistry of Bridging Ketene from Facile Carbonylation of a Ditungsten Methylene Complex with No Metal-Metal Bond
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- 作者：Yu-Lee Yang ; Luxti Jun-Jieh Wang ; Ying-Chih Lin ; Shou-Ling Huang ; Ming-Chou Chen ; Gene-Hsiang Lee ; and Yu Wang
- 刊名：Organometallics
- 出版年：1997
- 出版时间：April 15, 1997
- 年：1997
- 卷：16
- 期：8
- 页码：1573 - 1580
- 全文大小：212K
- 年卷期：v.16,no.8(April 15, 1997)
- ISSN：1520-6041
文摘
The reaction of Cp(CO)3W- (Cp =
5-C5H5) withCH2I2 in CH3CN at -20 
Cgives thedinuclear acetylide complexCp2(CO)6W2(
-C
C)(2). When the same reaction is carriedout in methanol at -20 C, a dinuclear ketene complex,Cp2(CO)5W2(,1,2-CH2CO)(5), isisolated. The oxygen atom of the ketene unit in 5 isweakly coordinated to one of the tungstenmetal centers. Upon dissolution in CH3CN at roomtemperature, complex 5 transforms to2. A bridging methylene complex,Cp2(CO)4[P(OMe)3]2W2(-CH2)(4a), has been isolated,and its facile carbonylation gives a different ketene complex,Cp2(CO)2[P(OMe)3]2W2(,1,1-CH2CO)(-CO) (6a), inCH3CN. Treatment of 5 with CO affordsCp2(CO)6W2(-CH2CO)(8),which, upon reacting with H2O, ROH (R = Me, Et,PhCH2), and i-PrNH2,generatesmononuclear complexes Cp(CO)3WCH2COOH(9), Cp(CO)3WCH2COOR(12a-c), andCp(CO)3WCH2CONH(i-Pr)(14), respectively. The more stable Cp' (Cp' =C5H4Me) analogues2', 5', and 8' are also prepared.An experiment using a mixture of 5 and 5' toafford only 2and 2' without the crossover product shows thatintermolecular coupling is not involved inthis transformation. The reaction of 5 withPR3 (R = OMe, Et, Ph) yields only thetransproductCp2(CO)5(PR3)W2(-CH2CO)(10a-c). But the reaction of 5with t-BuNC gives boththe trans and cis products of the ketene complexCp2(CO)5(t-BuNC)W2(-CH2CO)(11).Complexes 2', 5', 8', and11 have been characterized by single-crystal X-raydiffractionanalysis.
5-C5H5) withCH2I2 in CH3CN at -20 Cgives thedinuclear acetylide complexCp2(CO)6W2(-CC)(2). When the same reaction is carriedout in methanol at -20 C, a dinuclear ketene complex,Cp2(CO)5W2(,1,2-CH2CO)(5), isisolated. The oxygen atom of the ketene unit in 5 isweakly coordinated to one of the tungstenmetal centers. Upon dissolution in CH3CN at roomtemperature, complex 5 transforms to2. A bridging methylene complex,Cp2(CO)4[P(OMe)3]2W2(-CH2)(4a), has been isolated,and its facile carbonylation gives a different ketene complex,Cp2(CO)2[P(OMe)3]2W2(,1,1-CH2CO)(-CO) (6a), inCH3CN. Treatment of 5 with CO affordsCp2(CO)6W2(-CH2CO)(8),which, upon reacting with H2O, ROH (R = Me, Et,PhCH2), and i-PrNH2,generatesmononuclear complexes Cp(CO)3WCH2COOH(9), Cp(CO)3WCH2COOR(12a-c), andCp(CO)3WCH2CONH(i-Pr)(14), respectively. The more stable Cp' (Cp' =C5H4Me) analogues2', 5', and 8' are also prepared.An experiment using a mixture of 5 and 5' toafford only 2and 2' without the crossover product shows thatintermolecular coupling is not involved inthis transformation. The reaction of 5 withPR3 (R = OMe, Et, Ph) yields only thetransproductCp2(CO)5(PR3)W2(-CH2CO)(10a-c). But the reaction of 5with t-BuNC gives boththe trans and cis products of the ketene complexCp2(CO)5(t-BuNC)W2(-CH2CO)(11).Complexes 2', 5', 8', and11 have been characterized by single-crystal X-raydiffractionanalysis.