CO Dissociation Mechanism in Racemization of Alcohols by a Cyclopentadienyl Ruthenium Dicarbonyl Catalyst

详细信息    查看全文

• 作者：Madeleine C. Warner ; Oscar Verho ; Jan-E. B盲ckvall
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：March 9, 2011
• 年：2011
• 卷：133
• 期：9
• 页码：2820-2823
• 全文大小：756K
• 年卷期：v.133,no.9(March 9, 2011)
• ISSN：1520-5126

文摘

¹³CO exchange studies of racemization catalyst (畏⁵-Ph₅C₅)Ru(CO)₂Cl and (畏⁵-Ph₅C₅)Ru(CO)₂(Ot-Bu) by ¹³C NMR spectroscopy are reported. CO exchange for the active catalyst form, (畏⁵-Ph₅C₅)Ru(CO)₂(Ot-Bu) is approximately 20 times faster than that for the precatalyst (畏⁵-Ph₅C₅)Ru(CO)₂Cl. An inhibition on the rate of racemization of (S)-1-phenylethanol was observed on addition of CO. These results support the hypothesis that CO dissociation is a key step in the racemization of sec-alcohols by (畏⁵-Ph₅C₅)Ru(CO)₂Cl, as also predicted by DFT calculations.