Cobalt-Catalyzed Regiodivergent Hydrosilylation of Vinylarenes and Aliphatic Alkenes: Ligand- and Silane-Dependent Regioselectivities
作者:Chao Wang、Wei Jie Teo、Shaozhong Ge
DOI:10.1021/acscatal.6b02518
日期:2017.1.6
hydrosilylation of alkenes catalyzed by catalysts generated in situ from bench-stable Co(acac)2 and phosphine- or nitrogen-based ligands. A wide range of vinylarenes and aliphatic alkenes reacted to afford either branched (45 examples) or linear (37 examples) organosilanes in high isolated yields (average: 84%) and high regioselectivities (from 91:9 to >99:1). This transformation tolerates a variety of functional
NiCl2·6H2O/tBuOK, for the electrophilically activated hydrosilylation of terminal alkenes with primary silanes. This protocol provides excellent performance under mild reaction conditions: exclusive anti-Markovnikov selectivity, broad functional group tolerance (36 examples), and good scalability (TON = 5500). However, the secondary and tertiarysilanes are not suitable. Mechanistic studies revealed that
我们报告了一种简单有效的镍基催化体系NiCl 2 ·6H 2 O / t BuOK,用于末端烯烃与伯硅烷的亲电子活化氢化硅烷化。该方案在温和的反应条件下具有出色的性能:独特的抗马尔科夫尼科夫选择性,宽泛的官能团耐受性(36个示例)和良好的可扩展性(TON = 5500)。但是,仲和叔硅烷是不合适的。机理研究表明,这种均相催化的硅氢加成反应包括一种亲电子活化的Si-H键过程,而不会产生氢化镍。
<i>N,N</i>
‐Dimethylformamide‐protected Fe
<sub>2</sub>
O
<sub>3</sub>
Combined with Pt Nanoparticles: Characterization and Catalysis in Alkene Hydrosilylation
disclose a combination of N,N-dimethylformamide (DMF)-protected Fe2O3 nanoparticles (NPs) and Pt NPs catalyst system for the hydrosilylation of various functional alkenes and tertiarysilanes. The catalyst of DMF-protected Fe2O3/Pt NPs can be recycled for five times by a simple extraction. The developed combination Fe2O3/Pt NPs catalyst is effective up to the 1-kilogram scale.
纳米催化:我们公开了N,N-二甲基甲酰胺 (DMF) 保护的 Fe 2 O 3纳米粒子 (NPs) 和 Pt NPs 催化剂体系的组合,用于各种功能性烯烃和叔硅烷的氢化硅烷化。DMF保护的Fe 2 O 3 /Pt NPs催化剂可以通过简单的提取循环使用五次。所开发的 Fe 2 O 3 /Pt NPs 组合催化剂在 1 公斤级有效。
set of base metal catalysts has been developed for regiodivergent alkene hydrosilylations: iron complexes of phosphine‐iminopyridine are selective for anti‐Markovnikov hydrosilylations (linear/branched up to >99:1), while the cobalt complexes bearing the same type of ligands provide an unprecedented high level of Markovnikov selectivity (branched/linear up to >99:1). Both systems exhibit high efficiency
Titanium and zirconium complexes of the <i>N</i>,<i>N</i>′-bis(2,6-diisopropylphenyl)-1,4-diaza-butadiene ligand: syntheses, structures and uses in catalytic hydrosilylation reactions
作者:Srinivas Anga、Kishor Naktode、Harinath Adimulam、Tarun K. Panda
DOI:10.1039/c4dt02013h
日期:——
zirconium synthesised by a salt metathesis reaction. The reaction of either CpTiCl3 or Cp2TiCl2 with the dilithium salt of N,N′-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene [1; abbreviated (Dipp)2DADLi2] afforded the mono-cyclopentadienyl titanium complex [η5-CpTi((Dipp)2DAD)Cl] (2) bearing a dianionic ene-diamide ligand, while the analogous reaction of zirconocene dichloride (Cp2ZrCl2) with the