Experimental and Computational Studies of Ruthenium(II)-Catalyzed Addition of Arene C-H Bonds to Olefins
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- 作者：Marty Lail ; Christen M. Bell ; David Conner ; Thomas R. Cundari ; T. Brent Gunnoe ; and Jeffrey L. Petersen
- 刊名：Organometallics
- 出版年：2004
- 出版时间：October 11, 2004
- 年：2004
- 卷：23
- 期：21
- 页码：5007 - 5020
- 全文大小：299K
- 年卷期：v.23,no.21(October 11, 2004)
- ISSN：1520-6041
文摘
Hydroarylation reactions of olefins are catalyzed by the octahedral Ru(II) complex TpRu(CO)(NCMe)(Ph) (1) (Tp = hydridotris(pyrazolyl)borate). Experimental studies and densityfunctional theory calculations support a reaction pathway that involves initial acetonitrile/olefin ligand exchange and subsequent olefin insertion into the ruthenium-phenyl bond.Metal-mediated C-H activation of arene to form a Ru-aryl bond with release of alkyl arenecompletes the proposed catalytic cycle. The cyclopentadienyl complex CpRu(PPh3)2(Ph)produces ethylbenzene and styrene from a benzene/ethylene solution at 90 
C; however, thetransformation is not catalytic. A benzene solution of (PCP)Ru(CO)(Ph) (PCP = 2,6-(CH2PtBu2)2C6H3) and ethylene at 90 C produces styrene in 12% yield without observation ofethylbenzene. Computational studies (DFT) suggest that the C-H activation step does notproceed through the formation of a Ru(IV) oxidative addition intermediate but rather occursby a concerted pathway.
C; however, thetransformation is not catalytic. A benzene solution of (PCP)Ru(CO)(Ph) (PCP = 2,6-(CH2PtBu2)2C6H3) and ethylene at 90 C produces styrene in 12% yield without observation ofethylbenzene. Computational studies (DFT) suggest that the C-H activation step does notproceed through the formation of a Ru(IV) oxidative addition intermediate but rather occursby a concerted pathway.