26727-32-2Relevant academic research and scientific papers
Solvent free selective dehydrogenation of indolic and carbazolic molecules with an iridium pincer catalyst
Brayton, Daniel F.,Jensen, Craig M.
, p. 5987 - 5989 (2014/05/20)
A previously known iridium POCOP pincer catalyst was found to selectively dehydrogenate the heterocyclic portion of several indolic and carbazolic molecules. These molecules were found to have an "activity window" (172-178 °C) upon which only the heterocyclic ring underwent dehydrogenation. All reactions were run solvent free, yields for selected substrates were excellent, and the products were isolated by either distillation or alumina plug filtration. the Partner Organisations 2014.
Ruthenium nanoparticles supported on magnesium oxide: A versatile and recyclable dual-site catalyst for hydrogenation of mono- and poly-cyclic arenes, N-heteroaromatics, and S-heteroaromatics
Fang, Minfeng,Sanchez-Delgado, Roberto A.
, p. 357 - 368 (2014/02/14)
The development of catalysts capable of promoting hydrogenation of aromatics while being resistant to poisoning by nitrogen- and sulfur-containing species is of much interest in connection with hydrotreating of fossil fuels. We report a catalyst composed of ruthenium nanoparticles supported on magnesia, designed to promote heterolytic hydrogen splitting and surface ionic hydrogenation pathways. The catalyst, prepared through a one-pot procedure, promotes the hydrogenation of mono- and poly-cyclic arenes, as well as N- and S-heteroaromatics representative of fossil fuels components. Of particular significance are the superior activity and wider substrate scope of the catalyst, in relation to other known supported noble metals, and the excellent recyclability and long catalyst lifetime. Based on our experimental data, a dual-site catalyst structure and an associated dual-pathway mechanism are proposed, which may have interesting implications for the development of new poison-tolerant noble metal catalytic systems.
The Piloty-Robinson reaction of N-substituted piperidin-4-one azines. A novel route for the synthesis of 3,6-diazacarbazole
Alekseyev,Kurkin,Yurovskaya
experimental part, p. 584 - 596 (2012/01/12)
The possibility of preparing 1,2,3,4,6,7,8,9-octahydro-5H-pyrrolo[3,2-c:4, 5-c']dipyridines using the Piloty-Robinson reaction has been studied under various conditions. A novel method is proposed for the synthesis of the aromatic 3,6-diazacarbazole (5H-pyrrolo[3,2-c:4,5-c']dipyridine) from 2,8-dibenzoyl-1,2,3,4,6,7,8,9-octahydro-5H-pyrrolo[3,2-c:4,5-c']dipyridine obtained for the first time by the Piloty- Robinson method under thermal conditions.
Hydrogenation of arenes and N-heteroaromatic compounds over ruthenium nanoparticles on poly(4-vinylpyridine): A versatile catalyst operating by a substrate-dependent dual site mechanism
Fang, Minfeng,MacHalaba, Nataliya,Sanchez-Delgado, Roberto A.
experimental part, p. 10621 - 10632 (2011/11/29)
A nanostructured catalyst composed of Ru nanoparticles immobilized on poly(4-vinylpyridine) (PVPy) has been synthesized by NaBH4 reduction of RuCl3·3H2O in the presence of the polymer in methanol at room temperature. TEM measurements show well-dispersed Ru nanoparticles with an average diameter of 3.1 nm. Both powder XRD patterns and XPS data indicate that the Ru particles are predominantly in the zerovalent state. The new catalyst is efficient for the hydrogenation of a wide variety of aromatic hydrocarbons and N-heteroaromatic compounds representative of components of petroleum-derived fuels. The experimental data indicate the existence of two distinct active sites in the nanostructure that lead to two parallel hydrogenation pathways, one for simple aromatics involving conventional homolytic hydrogen splitting on Ru and a second one for N-heteroaromatics taking place via a novel heterolytic hydrogen activation on the catalyst surface, assisted by the basic pyridine groups of the support.
Reduction of the indole ring system: Synthesis of 4,5,6,7-tetrahydroindoles
McComas, Casey C.,Van Vranken, David L.
, p. 8039 - 8043 (2007/10/03)
A general two-step procedure for the reduction of indoles to the corresponding 4,5,6,7-tetrahydroindoles has been developed. A regioselective Birch reduction followed by catalytic hydrogenation is employed to accomplish this transformation. Yields for the sensitive pyrrole products are typically between 40 and 50%. This method provides access to complex chiral pyrroles that cannot be readily prepared by other methods.
A General Synthesis of Pyrroles from Aldehydes and Ketones
Baldwin, Jack E.,Bottaro, Jeffrey C.
, p. 624 - 625 (2007/10/02)
The azines of enolisable aldehydes and ketones are converted into pyrroles via thermal rearrangement of the derived benzoyl derivatives and subsequent hydrazinolysis of the resulting N-benzoylpyrroles.
