Reactivity of Cr(III) μ-Oxo Compounds: Catalyst Regeneration and Atom Transfer Processes
作者:K. Cory MacLeod、Brian O. Patrick、Kevin M. Smith
DOI:10.1021/ic202233f
日期:2012.1.2
When CpCr[(DepNCMe)2CH] was treated with pyridineN-oxide in benzene in the absence of hydrogen atom donors, a dimeric Cr(III) hydroxide product was isolated and structurally characterized, apparently resulting from intramolecular hydrogen atom abstraction of a secondary benzylic ligand C–H bond followed by intermolecular C–C bond formation. The use of very bulky hexaisopropylterphenyl ligand substituents
用吡啶N-氧化物或空气氧化CPCr [(XylNCMe)2 CH](Xyl = 2,6-Me 2 C 6 H 3)生成μ-氧代二聚体CPCr [(XylNCMe)2 CH]} 2( μ-O)。μ-氧代二聚体通过质子分解反应转化为顺磁性Cr(III)CPCr [(XylNCMe)2 CH](X)配合物(X = OH,O 2 CPh,Cl,OTs)。相关的Cr(III)醇盐配合物(X = OCMe 3,OCMe 2Ph)是通过盐复分解制备的,并通过单晶X射线衍射进行了表征。使用紫外-可见光谱法监测Cr(III)配合物的相互转化及其与Mn粉还原为Cr(II)的过程。研究了相关的CPCr [(DepNCMe)2 CH](Dep = 2,6-Et 2 C 6 H 3)Cr(II)配合物在O 2或空气中与PPh 3的催化氧原子转移反应。两种Cr(II)配合物均与吡啶N-氧化物和γ-萜品烯反应生成相应