Heavier Alkaline‐Earth Catalyzed Dehydrocoupling of Silanes and Alcohols for the Synthesis of Metallo‐Polysilylethers
作者:Louis J. Morris、Michael S. Hill、Mary F. Mahon、Ian Manners、Fred S. McMenamy、George R. Whittell
DOI:10.1002/chem.201905313
日期:2020.3.2
The dehydrocoupling of silanes and alcohols mediated by heavier alkaline-earth catalysts, [AeN(SiMe3 )2 }2 ⋅(THF)2 ] (I-III) and [AeCH(SiMe3 )2 }2 ⋅(THF)2 ], (IV-VI) (Ae=Ca, Sr, Ba) is described. Primary, secondary, and tertiary alcohols were coupled to phenylsilane or diphenylsilane, whereas tertiary silanes are less tolerant towards bulky substrates. Some control over reaction selectivity towards
较重的碱土催化剂[Ae N(SiMe3)2} 2⋅(THF)2](I-III)和[Ae CH(SiMe3)2} 2⋅(THF)介导的硅烷和醇的脱氢偶联参照图2,描述(IV-VI)(Ae = Ca,Sr,Ba)。伯,仲和叔醇与苯基硅烷或二苯基硅烷偶联,而叔硅烷对大体积底物的耐受性较低。通过改变反应化学计量,条件和催化剂,可以实现对单,二或三取代甲硅烷基醚产物的反应选择性的一些控制。制备了二茂铁基硅烷基醚FeCp(C5H4SiPh(OBn)2)(2),并使用钡催化从二茂铁基硅烷,FeCp(C5H4SiPhH2)(1)和苯甲醇中充分表征。化学计量实验表明,反应流形涉及乙氧基醇和氢化物的形成,并分离出一系列二聚Ae醇盐[(Ph3 CO)Ae(μ2-OCPh3)Ae(THF)](3 ac,Ae = Ca,Sr,Ba)并进行了充分表征。机理实验表明,涉及二聚或多核活性物质的反应机制复杂,其动力学高