@article { ISI:000233927900005, title = {Synthesis, characterization and catalytic application of Ru-II-ethylenediamine complex - mesoporous silica as heterogeneous catalyst system in chemo-selective hydrogenation of alpha,beta-unsaturated carbonyl compounds}, journal = {Microporous and Mesoporous Materials}, volume = {87}, number = {1}, year = {2005}, month = {DEC}, pages = {33-44}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

An efficient heterogeneous catalyst system for chemo-selective hydrogenation of alpha,beta-unsaturated aldehydes was synthesized, involving anchoring of a Ru-II-phosphine complex on the inner surfaces of organo-functionalized (propylamine and propylethylenediamine) mesoporous MCM-41 and MCM-48 materials. Powder XRD, SEM and TEM experiments reveal highly ordered hexagonal and cubic patterns of the organically modified MCM-41 and MCM-48 materials, respectively, even after incorporation of Ru complexes. Moreover, the integrity of the Ru complex was retained after anchoring into the mesoporous hosts, which was supported by FTIR, P-31 CP MAS NMR and XPS analyses. This heterogeneous catalyst shows promising activity and chemo-selectivity towards hydrogenation of carbonyl groups in alpha,beta-unsaturated aldehydes. The effects of reaction temperature, reaction time and hydrogen pressure on the activity and selectivity were studied in detail. The anchored solid catalysts can be recycled effectively and reused several times without any loss in activity and selectivity. Although, the initial activity of the same Ru complex when grafted onto the organically modified surfaces of fumed silica is comparable to corresponding MCM41/MCM-48 catalysts, the activity and chemo-selectivity significantly decrease during recycle of the catalyst due to leaching. (c) 2005 Elsevier Inc. All rights reserved.

}, keywords = {chemo-selective, heterogeneous catalysis, Heterogenization, Hydrogenation, mesoporous materials, organo-functionalization, Ru-II-ethylenediamine complex, unsaturated aldehyde}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2005.06.042}, author = {Ghosh, Anirban and Kumar, R} } @article { ISI:000237318000033, title = {Chemoselective anti-Markovnikov hydroamination of alpha,beta-ethylenic compounds with amines using montmorillonite clay}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {250}, number = {1-2}, year = {2006}, month = {MAY}, pages = {210-217}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The catalytic activity of montmorillonite clays as a catalyst for the hydroamination of alpha,beta-ethylenic compounds with amines was tested. Aniline and substituted amines reacted with alpha,beta-ethylenic compounds in the presence of catalytic amount of commercially available clay to afford exclusively anti-Markovnikov adduct in excellent yields. Aniline reacted with ethyl acrylate to yield only anti-Markovnikov adduct N-[2-(ethoxycarbonyl)ethyl] aniline (mono-addition product). No Markovnikov adduct (N-[1-(ethoxycarbonyl)ethyl]aniline and double addition product N,N-bis[2-(ethoxycarbonyl)ethyl]aniline were formed under selected reaction conditions. For a better exploitation of the catalytic activity in terms of increased activity and improved selectivity for the mono-addition product, the reaction parameters were optimized in terms of temperature, solvent, reactant mole ratio. Under optimized reaction conditions, montmorillonite clay K-10 showed a superior catalytic performance in the hydroamination of ethyl acrylate with aniline with a conversion of aniline to mono-addition product (almost 100\% chemoselectivity) with a high rate constant 0.3414 min(-1) compared to the reported protocols. The dependence of conversion of aniline over different types of montmorillonite clays (K-10, K-20, K-30, Al-Pillared clay and untreated clay) has also been discussed. The activities of clay for the hydroamination of different aromatic and aliphatic amines have also been investigated. Under harsh reaction conditions (increased temperature and long reaction time) small amounts of di-addition products were observed. The kinetics data has been interpreted using the initial rate approach model. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {alpha, amines, anti-Markovnikov addition product, beta-ethylenic compounds, chemo-selective, hydroamination, K-10 montmorillonite clay}, issn = {1381-1169}, doi = {10.1016/j.molcata.2006.01.062}, author = {Joseph, Trissa and Shanbhag, G. V. and Sawant, D. P. and Halligudi, Shivappa B.} } @article {44217, title = {Ru(II)-functionalized SBA-15 as highly chemoselective, acid free and sustainable heterogeneous catalyst for acetalization of aldehydes and ketones}, journal = {Catalysis Communications}, volume = {104}, year = {2018}, month = {JAN}, pages = {62-66}, type = {Article}, abstract = {

Combining electron deficient Ru(II) coordination sites with organofunctionalized SBA-15, (L)Ru(Il)@SBA-15, result in a mild, neutral, water scavenger free and chemo-selective acetalization catalyst for cyclic/acyclic acetals. Vacant coordination sites of ruthenium in (L)Ru(II)@SBA-15 activates protecting groups as well as reactants simultaneously and restricts the reverse acetalization reaction. Synthesized (L)Ru(Il)@SBA-15 catalyst has been thoroughly characterized and act as competitive catalyst compared to conventional acid catalysts. (L) RuaD@SBA-15 performs high catalytic activity as well as selectivity within 20 min with high TOF. The catalyst can be recycled and reaction parameters are optimized.

}, keywords = {Acetalization reactions, Acid free, chemo-selective, heterogeneous catalyst, Reusable, Ru(II) immobilized SBA-15}, issn = {1566-7367}, doi = {10.1016/j.catcom.2017.10.016}, author = {Lazar, Anish and Betsy, K. J. and Vinod, C. P. and Singh, A. P.} }