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Syntheses of Molybdenum and Tungsten Imido Alkylidene Complexes that Contain a Bidentate Oxo/Thiolato Ligand
Helvetica Chimica Acta ( IF 1.5 ) Pub Date : 2020-05-25 , DOI: 10.1002/hlca.202000068
Hosein Tafazolian 1, 2 , Sudarsan VenkatRamani 1 , Charlene Tsay 2 , Richard R. Schrock 1, 2 , Peter Müller 1
Affiliation  

3,3′,5,5′‐Tetra‐tert‐butyl‐2′‐sulfanyl[1,1′‐biphenyl]‐2‐ol (H2[tBu4OS]) was prepared in 24 % yield overall from the analogous biphenol using standard techniques. Addition of H2[tBu4OS] to Mo(NAr)(CHCMe2Ph)(2,5‐dimethylpyrrolide)2 led to formation of Mo(NAr)(CHCMe2Ph)[tBu4OS], which was trapped with PMe3 to give Mo(NAr)(CHCMe2Ph)[tBu4OS](PMe3) (1(PMe3)). An X‐ray crystallographic study of 1(PMe3) revealed that two structurally distinct square pyramidal molecules are present in which the alkylidene ligand occupies the apical position in each. Both 1(PMe3)A and 1(PMe3)B are disordered. Mo(NAd)(CHCMe2Ph)(tBu4OS)(PMe3) (2(PMe3); Ad=1‐adamantyl) and W(NAr)(CHCMe2Ph)(tBu4OS)(PMe3) (3(PMe3)) were prepared using analogous approaches. 1(PMe3) reacts with ethylene (1 atm) in benzene within 45 minutes to give an ethylene complex Mo(NAr)(tBu4OS)(C2H4) (4) that is isolable and relatively stable toward loss of ethylene below 60 °C. An X‐ray study shows that the bond distances and angles for the ethylene ligand in 4 are like those found for bisalkoxide ethylene complexes of the same general type. Complex 1(PMe3) in the presence of one equivalent of B(C6F5)3 catalyzes the homocoupling of 1‐decene, allyltrimethylsilane, and allylboronic acid pinacol ester at ambient temperature. 1(PMe3), 2(PMe3), and 3(PMe3) all catalyze the ROMP of racendo,exo‐5,6‐dicarbomethoxynorbornene (rac‐DCMNBE) in the presence of B(C6F5)3, but the polyDCMNBE that is formed has a random structure.

中文翻译:

钼和钨亚氨基亚炔基络合物的合成,其含双齿含氧/硫醇基配体

制备3,3',5,5'-四叔丁基-2-2'-硫烷基[1,1'-联苯] -2-醇(H 2 [ t Bu 4 OS]),总产率为24%使用标准技术的类似双酚。在Mo(NAr)(CHCMe 2 Ph)(2,5-二甲基吡咯化物)2中添加H 2 [ t Bu 4 OS]导致形成Mo(NAr)(CHCMe 2 Ph)[ t Bu 4 OS],这是用PMe 3捕集得到Mo(NAr)(CHCMe 2 Ph)[ t Bu 4 OS](PMe 3)(1(PMe 3))。对1(PMe 3)的X射线晶体学研究表明,存在两个结构上不同的方形锥体分子,其中亚烷基配体在每个锥体中占据顶位。两个1(PME 31(PME 3被无序。Mo(NAd)(CHCMe 2 Ph)(t Bu 4 OS)(PMe 3)(2(PMe 3); Ad = 1-金刚烷基)和W(NAr)(CHCMe 2 Ph)(t Bu 4 OS)(PMe 3)(3(PMe 3))是使用类似方法制备的。1(PMe 3)与乙烯(1 atm)在苯中的反应在45分钟内产生乙烯络合物Mo(NAr)(t Bu 4 OS)(C 2 H 4)(4),该络合物可分离且相对稳定,不会丢失低于60°C的乙烯。X射线研究表明,乙烯配体在4中的键距和夹角与相同类型的双烷氧基乙烯配合物的键距和夹角相似。在一当量的B(C 6 F 53存在下的络合物1(PMe 3在环境温度下催化1-癸烯,烯丙基三甲基硅烷和烯丙基硼酸频哪醇酯的均偶联。1(PMe 3),2(PMe 3)和3(PMe 3)在存在B(C 6 F 5)的情况下均催化rac - endoexo -5,6-二苯甲氧基降冰片烯(rac -DCMNBE )的ROMP。如图3所示,但是形成的polyDCMNBE具有随机结构。
更新日期:2020-05-25
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