18492-59-6Relevant articles and documents
Synthesis of bimetallic Zr(Ti)-naphthalendicarboxylate MOFs and their properties as Lewis acid catalysis
Rasero-Almansa, Antonia M.,Iglesias, Marta,Sánchez, Félix
, p. 106790 - 106797 (2016/11/23)
Bimetallic Zr(Ti)-NDC based metal-organic frameworks (MOFs) have been prepared by incorporation of titanium(iv) into zirconium(iv)-NDC-MOFs (UiO family). The resulting materials maintain thermal (up to 500 °C), chemical and structural stability with respect to parent Zr-MOFs as can be deduced from XRD, N2 adsorption, FTIR and thermal analysis. The materials have been studied in Lewis acid catalyzed reactions, such as, domino Meerwein-Ponndorf-Verley (MPV) reduction-etherification of p-methoxybenzaldehyde with butanol, isomerization of α-pinene oxide and cyclization of citronellal.
Application of an indenyl molybdenum dicarbonyl complex in the isomerisation of α-pinene oxide to campholenic aldehyde
Bruno, Sofia M.,Gomes, Ana C.,Gamelas, Carla A.,Abrantes, Marta,Oliveira, M. Concei??o,Valente, Anabela A.,Almeida Paz, Filipe A.,Pillinger, Martyn,Rom?o, Carlos C.,Gon?alves, Isabel S.
, p. 3172 - 3180 (2014/07/07)
The complex [{(η5-Ind)Mo(CO)2(μ-Cl)} 2] (1) has been tested for the industrially relevant catalytic isomerisation of α-pinene oxide (PinOx) to campholenic aldehyde (CPA) in the liquid phase. PinOx conversion and CPA selectivity are strongly influenced by the solvent employed. Complete conversion of PinOx was achieved within 1 min at 55 °C or 30 min at 35 °C using 1,2-dichloroethane as solvent, giving CPA in 68% yield. Other products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The stability of 1 under the reaction conditions used was investigated by using FT-IR spectroscopy and electrospray ionisation mass spectrometry (ESI-MS) to characterise recovered solids. In the presence of air/moisture 1 undergoes oxidative decarbonylation upon dissolution to give oxomolybdenum species that are proposed to include a tetranuclear oxomolybdenum(v) complex. Conversely, ESI-MS studies of 1 dissolved in dry acetonitrile show mononuclear species of the type [IndMo(CO)2(CH 3CN)n]+. The crystal structure of the ring-slipped dicarbonyl complex [(η3-Ind)Mo(CO) 2Cl(CH3CN)2] (2) (obtained after dissolution of 1 in acetonitrile) is reported. the Partner Organisations 2014.
Studies on the Oxidation of cis- and trans-Pinane with Molecular Oxygen
Brose, Thomas,Pritzkow, Wilhelm,Thomas, Gerda
, p. 403 - 409 (2007/10/02)
The pinanes are preferably attacked at the tertiary C-H bond in 2-position, but products of the oxidative attack at the secondary C-H-bonds in 3- and 4-position are also found.At 100 deg C cis-pinane is attacked more easily than trans-pinane (kcis : ktrans = 6.4), the relative rates of attack at the secondary C-H bonds in positions 3 and 4 with respect to the tertiary C-H bond in 2-position were also determined (in cis-pinane ksec : ktert = 0.027; in trans-pinane ksec : ktert = 0.20).After the attack at the 2-C-H bond the radical formed can either react with oxygen to form the corresponding cis- and trans-peroxy radicals and further to give cis- and trans-2-hydroperoxy pinane or fragmentate to the monocyclic radical derived from α-terpinene, giving as a final products α-terpinene hydroperoxide and the bicyclic 8-hydroperoxy 4,4,8-trimethyl 2,3-dioxabicyclononane.The corresponding alcohols were found after reduction with sodium sulphite.The oxidation at position 2 of the pinanes delivers not only the cis- and trans-hydroperoxide but also, as short-lived intermediates, the corresponding 2-pinanyloxy radicals.These radicals fragmentate forming a carbon radical with cyclobutane structure whose oxidation products were identified.Besides fragmentation of the 2-pinanyloxy radical also an intramolecular H-transfer from the methyl group in 9-position to the oxygen of the trans-pinanyloxy radical takes place leading to 9-hydroperoxy trans-pinane-2-ol.
