5116-65-4Relevant articles and documents
Syntheses and spectroscopic characterizations of oxidative metabolites of 4-vinylcyclohexene
Mash,Gregg,Sipes
, p. 235 - 239 (1994)
The 7,8-epoxide and 7,8-diol derivatives of 4-vinylcyclohexene were prepared and characterized spectroscopically for use as standards in toxicological studies of the oxidative metabolism of the parent hydrocarbon.
A stand-alone cobalt bis(dicarbollide) photoredox catalyst epoxidates alkenes in water at extremely low catalyst load
Guerrero, Isabel,Romero, Isabel,Teixidor, Francesc,Vi?as, Clara
supporting information, p. 10123 - 10131 (2021/12/27)
The cobalt bis(dicarbollide) complex, Na[3,3′-Co(η5-1,2-C2B9H11) (Na[1]), is an effective photoredox catalyst for the oxidation of alkenes to epoxides in water. Advantageous features of Na[1] include its lack of photoluminescence, high solubility and surfactant behavior in aqueous media, as well as the donor ability of the carborane ligand and high oxidizing power of the Co4+/3+ couple. These features differentiate it from the well-known and widely used photosensitizer tris (2,2′-bipyridine) ruthenium(ii) ([Ru(bpy)3]2+), which also participates in electron transfer through an outer sphere mechanism. A comparison of the catalytic performance of [Ru(bpy)3]2+ with Na[1] for alkene photo-oxidation is fully in favor of Na[1], as the former shows very low or null efficiency. With a catalyst loading of 0.1 mol% conversions between 65-97% have been obtained in short reaction times, 15 minutes, with moderate selectivity for the corresponding epoxide, due to the formation of side products as diols. But when the catalyst loading is reduced to 0.01 mol%, the selectivity for the corresponding epoxide increased considerably, being the only compound formed after 15 minutes of reaction (selectivity >99%). High TON values have been obtained (TON = 8500) for the epoxidation of aromatic and aliphatic alkenes in water. We have verified that Na[3,3′-Co(η5-1,2-C2B9H11)2] acts as a photocatalyst in both the epoxidation of alkenes and in their hydroxylation in aqueous medium with a higher rate for epoxidation than for hydroxylation. Preliminary photooxidation tests using methyl oleate as the substrate led to the selective epoxidation of the double bond. These results represent a promising starting point for the development of practical methods for the processing of unsaturated fatty acids, such as the valorisation of animal fat waste using this sustainable photoredox catalyst. This journal is
Carboranycarboxylate Complexes as Efficient Catalysts in Epoxidation Reactions
Fontanet, Mònica,Rodríguez, Montserrat,Vi?as, Clara,Teixidor, Francesc,Romero, Isabel
, p. 4425 - 4429 (2017/10/06)
This work presents the first examples of carboranylcarboxylate complexes as precatalysts in epoxidation reactions with the use of peracetic acid as the oxidant. The manganese [Mn(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)2]n·(H2O)n (1), [Mn2(1-CH3-2-CO2-1,2-closo-C2B10H10)4(2,2′-bpy)2] (2, bpy = bipyridine), [Mn(1-CH3-2-CO2-1,2-closo-C2B10H10)2(bpm)]n (3, bpm = bipyrimidine), and [Mn(1-CH3-2-CO2-1,2-closo-C2B10H10)2(2,2′-bpy)2] (4) complexes and the cobalt [Co2(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)4(thf)4] (6) complex, all containing the carboranylcarboxylic 1-CH3-2-CO2H-1,2-closo-C2B10H10 (LH) ligand, together with Mn3(OAc)6(2,2′-bpy)2 (5) displayed good performance with high conversions and selectivity values in short reaction times, in most cases. This work highlights that the coordination of the carboranylcarboxylic ligand to the metal ions is crucial to the performance of the complexes as catalysts.
Designing the synthesis of catalytically active Ti-β by using various new templates in the presence of fluoride anion
Sasidharan, Manickam,Bhaumik, Asim
experimental part, p. 16282 - 16294 (2012/01/14)
Crystallization of large-pore Ti-β by using a variety of diquaternary ammonium derivatives of dibromoalkane and amines such as triethylamine, 1,4-diazabicyclo[2,2,2]octane (DABCO), and quinuclidine as structure-directing agents (SDA) is described. The size of hydrophobic bridging alkyl-chain length of the template [R3N+-(CH2)x-N +R3](OH-)2 directs the final crystalline product: Ti-β, Ti-ZSM-12, Ti-nonasil or Ti-ZSM-5, as x gradually changes from 6 to 1, in the fluoride medium under hydrothermal conditions. A dense phase such as Ti-nonasil (clathrasil type) is crystallized as the size of hydrophobic bridging alkyl-chain length decreases. The use of F- anions as a mineralizer and Ti4+ as a heteroatom in the synthesis gel also influences the selectivity of final crystalline product. The phase purity and incorporation of Ti4+ into the lattice of β (BEA) and ZSM-12 frameworks are confirmed using XRD, UV-visible, FT-IR, 29Si NMR spectroscopes, elemental analysis (ICP), surface area measurements and catalytic test reactions. The morphology of Ti-β samples is dependent on the nature of the structure-directing agent as revealed by the scanning electron microscopic (SEM) observations. The catalytic activity in the epoxidation of 4-vinyl-1-cyclohexene is increased with the amount of tetrahedral Ti4+ atoms in the framework. The new templates can be effectively used for preparation of catalytically active Ti-β with the minimum number of framework defect sites.
