Synthesis of [RuCl2(NO)2(THF)] and its Double C-N Bond-Forming Reactions with Alkenes
Synthesis of [RuCl2(NO)2(THF)] and its Double C-N Bond-Forming Reactions with Alkenes
复制标题
DOI：
10.1002/anie.201100816
复制
发表时间：
2011-01-01
影响因子：
16.6
通讯作者：
Toste, F. Dean
中科院分区：
文献类型：
--
作者：
Crimmin, Mark R.;Bergman, Robert G.;Toste, F. Dean
虽然相对惰性的气体，如氮气和一氧化碳与有机金属络合物的活化仍然是一个深入研究的主题，但控制一氧化氮在过渡金属中心的反应活性的方法却受到相当少的关注。[1-3]例如，只有少数金属络合物观察到NO迁移插入到金属-烷基或金属-芳基键中，尽管一氧化碳在其有机金属化学中占主导地位，并且是许多均相催化过程中的关键步骤。尽管在这一领域缺乏研究可能反映了NO的复杂背景反应性，[4]开发包含NO的选择性反应形成新的碳-氮键的潜力代表了有机合成中一种有吸引力的方法。正是在这种背景下，我们对金属亚硝基配合物与烯烃的反应感兴趣。[5]在没有金属配位的情况下，NO与烯烃的反应化学是不规范的。[4]此外，只有少数过渡金属配合物选择性地促进了这一反应。因此，在Brunner和Loskot早期发现的启发下，我们在20世纪80年代证明了[{CPCO(NO)}2]，NO与应变的或烷基取代的烯烃干净地反应，形成相应的二亚硝烷配合物[1，式(1)]。[2，5a-c]最近，这种化学已被用来开发一种形成C±C键的方法。此外，K[IrCl5(NO)]与烯烃的反应生成亚硝酸Ir-烷烃配合物，[6]和[TpRuCl2(NO)](TP=三(吡唑基)硼酸酯)与2-乙烯基吡啶反应生成亚硝烯络合物的报道。[7]尽管有上述反应，金属亚硝酰的C±N键形成反应并不多，双重加成反应尤其罕见。我们现在报告这种类型的反应的一个例子，新型的二亚硝基配合物[RuCl2(NO)2(THF)]，它在室温下在另一个中性螯合配体L2的存在下，将烯烃与亚硝酰氮原子结合。[{(伞花烃)RuCl2}2]与10当量降冰片二烯在[D8]四氢呋喃中，在一氧化氮气氛中反应生成六配位的Ru二亚硝烷加合物[(THF)2RuCl2{(μ-NO)2(C7H8)}]，产率为86%。
While the activation of relatively inert gases such as N2 and CO with organometallic complexes remains a topic of intense investigation, methods for controlling the reactivity of nitric oxide at transition-metal centers have received considerably less attention.[1–3] For example, the migratory insertion of NO into metal–alkyl or metal–aryl bonds has been observed in only a handful of metal complexes,[3] despite the analogous reaction of CO dominating its organometallic chemistry and being the key step in many homogeneous catalytic processes. Although the paucity of studies in this field may be a reflection of the often complicated background reactivity of NO,[4] the potential to develop selective reactions incorporating NO that form new carbon–nitrogen bonds represents an attractive approach in organic synthesis. It is in this context that we are interested in the ligandbased reaction of metal nitrosyl complexes with alkenes.[5] In the absence of metal coordination the reaction chemistry of NO with alkenes is unruly.[4] Furthermore, only a few transition-metal complexes have been shown to promote this reaction selectively. Thus, inspired by an early finding of Brunner and Loskot, we demonstrated in the 1980s that [{CpCo (NO)} 2], NO and strained or alkyl-substituted alkenes react cleanly to form the corresponding dinitrosoalkane complexes [1, Eq.(1)].[2, 5a–c] More recently this chemistry has been used to develop a method for CÀC bond formation.[5d, e] In addition, the reaction of K [IrCl5 (NO)] with alkenes to yield iridium nitrosoalkane complexes,[6] and the reaction of [TpRuCl2 (NO)](Tp= tris (pyrazolyl) borate) with 2-vinylpyridine to yield a nitrosoalkene complex have been reported.[7]In spite of the above reactions, there are not many CÀN bond-forming reactions of metal nitrosyls and double additions remain especially rare. We now report an example of this type of reactivity with the novel dinitrosyl complex [RuCl2 (NO) 2 (THF)], which binds alkenes to the nitrosyl nitrogen atoms at room temperature in the presence of an additional neutral chelating ligand, L2. The reaction of [{(cymene) RuCl2} 2] with 10equiv of norbornadiene under an atmosphere of nitric oxide in [D8] THF gave a putative six-coordinate ruthenium dinitrosoalkane adduct [(THF) 2RuCl2 {(μ-NO) 2 (C7H8)}] in 86% yield as evidenced by 1H NMR spectroscopy (Scheme 1).