Abnormal N-Heterocyclic Carbene-Phosphine Ruthenium(II) Complexes as Active Catalysts for Transfer Hydrogenation

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• 作者：Julia Witt ; Alexander P枚thig ; Fritz E. K眉hn ; Walter Baratta
• 刊名：Organometallics
• 出版年：2013
• 出版时间：August 12, 2013
• 年：2013
• 卷：32
• 期：15
• 页码：4042-4045
• 全文大小：234K
• 年卷期：v.32,no.15(August 12, 2013)
• ISSN：1520-6041

文摘

The bifunctional phosphine鈥揳bnormal N-heterocyclic carbene ruthenium(II) complex RuBr(OAc)(PPh₃)(P鈥揳NHC) (1) has been synthesized in high yield by reaction of Ru(OAc)₂(PPh₃)₂ with a phosphine imidazolium bromide (P鈥揘HC 脳 HBr) and characterized by X-ray diffraction. This compound shows high catalytic activity for the transfer hydrogenation of ketones to alcohols in 2-propanol. Rate and efficiency of 1 can be enhanced by the addition of ethylenediamine or benzylamine, affording TOFs up to 140鈥?00 h^鈥?. Reaction of 1 with ethylenediamine leads to the Ru carbene/amine complex [Ru(OAc)(PPh₃)(P鈥揳NHC)(H₂NCH₂CH₂NH₂)]Br (2), which displays the same activity of the in situ generated species.