C=C双键与分子氧的氧化裂解产生羰基化合物是化学和药物合成中的一个重要转化。在自然界中,含有第一排过渡金属的酶,特别是血红素和非血红素铁依赖性酶,在环境条件下很容易激活 O 2并以极其精确的方式氧化裂解 C=C 键。然而,该反应对合成化学家来说仍然具有挑战性。只有少数已知的合成金属催化剂允许在 O 2大气压下氧化裂解烯烃,很少有人知道催化未活化烯烃的裂解。在这项工作中,我们描述了一种光驱动、Mn 催化的协议,用于在 1 个大气压的 O 2下将烯烃选择性氧化为羰基化合物。首次使用第一排生物相关金属催化剂,在清洁、温和的条件下,可以将芳香族和各种未活化的脂肪族烯烃氧化成酮和醛。此外,该协议显示出非常好的功能组耐受性。机理研究表明,Mn-oxo 物种,包括不对称的混合价双 (μ-oxo)-Mn(III,IV) 络合物,参与氧化,溶剂甲醇参与 O 2活化,导致oxo 物种的形成。
Zirconocene dichlorides as catalysts in alkene carbo- and cyclometalation by AlEt<sub>3</sub>: intermediate structures and dynamics
作者:Lyudmila V. Parfenova、Pavel V. Kovyazin、Olesia V. Mukhamadeeva、Pavel V. Ivchenko、Ilya E. Nifant'ev、Leonard M. Khalilov、Usein M. Dzhemilev
DOI:10.1039/d1dt03160k
日期:——
A series of zirconocenes L2ZrCl2 (23 examples) were studied as catalysts in the reaction of alkenes with AlEt3. The catalyst activity and reaction chemoselectivity were found to depend on the ligand structure in the complex and the nature of the solvent. The alkyl exchange in the triethylaluminum dimer was studied by NMR spectroscopy; a solvent effect on the alkyl exchange parameters was established
Effect of Alcohol Structure on the Kinetics of Etherification and Dehydration over Tungstated Zirconia
作者:Julie Rorrer、Suresh Pindi、F. Dean Toste、Alexis T. Bell
DOI:10.1002/cssc.201801067
日期:2018.9.21
energies for etherification and dehydration, demonstrating the possibility to produce both symmetrical and asymmetrical linear ethers. Reactions over a series of C6 alcohols with varying methyl branch positions indicated that substituted alcohols (2°, 3°) and alcohols with branches on the β‐carbon readily undergo dehydration, but alcohols with branches at least three carbons away from the ‐OH group are
Diastereoselective synthesis of functionally substituted alkene dimers and oligomers, catalysed by chiral zirconocenes
作者:Pavel V. Kovyazin、Il'giz N. Abdullin、Lyudmila V. Parfenova
DOI:10.1016/j.catcom.2018.10.032
日期:2019.1
The research addresses the reaction of terminal alkenes and propene with AlR3 (R = Me, Et) in the presence of chiral Zr complexes, rac-[Y(η5-C9H10)2]ZrCl2 (Y = C2H4, SiMe2) or (NMI)2ZrCl2 (NMI- η5–neomenthylindenyl), and methylaluminoxane. The effect of reaction conditions, catalyst and trialkylalane structure on the substrate conversion and the reaction chemo- and stereoselectivity has been studied
研究地址末端烯烃的反应和丙烯与为AlR 3中的手性锆复合物,的存在下(R =甲基,乙基)外消旋- [Y(η 5 -C 9 ħ 10)2 ]的ZrCl 2(Y = C 2 ħ 4,森达2)或(NMI)2的ZrCl 2(NMI- η 5–neomenthylindenyl)和甲基铝氧烷。研究了反应条件,催化剂和三烷基铝烷结构对底物转化率以及反应化学和立体选择性的影响。该反应主要经历烯烃甲基(乙基)锆化的阶段,随后将底物分子引入Zr-C键中。结果,开发了用于合成官能取代的线性末端烯烃二聚体和丙烯低聚物的非对映选择性一锅法。
Structurally uniform 1-hexene, 1-octene, and 1-decene oligomers: Zirconocene/MAO-catalyzed preparation, characterization, and prospects of their use as low-viscosity low-temperature oil base stocks
作者:Ilya E. Nifant’ev、Alexander A. Vinogradov、Alexey A. Vinogradov、Igor V. Sedov、Viktor G. Dorokhov、Anton S. Lyadov、Pavel V. Ivchenko
DOI:10.1016/j.apcata.2017.09.016
日期:2018.1
alkanes, and higher oligomers. Trimers, tetramers, and pentamers of 1-hexene, 1-octene, and 1-decene were isolated as individual compounds and were hydrogenated. Viscosity characteristics of the isolated saturated and unsaturated hydrocarbons have been studied at various temperatures. The isolated saturated oligomers of 1-octene and 1-decene outperform the traditional electrophilic oligomerization