@article { ISI:000230389700020, title = {Copper(II) ion-exchanged montmorillonite as catalyst for the direct addition of N-H bond to CC triple bond}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {236}, number = {1-2}, year = {2005}, month = {JUL}, pages = {139-144}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

An efficient synthesis of phenyl-(1-phenylethylidene)amine using copper-exchanged montmorillonite clay (Cu K-10) is demonstrated. The catalyst was characterized using UV-vis, XRD, BET surface area measurements, pyridine adsorption etc. The XRD and surface area measurement show that the structural characteristics of the support montmorillonite K-10 (K-10) are preserved after Cu exchange. The hydroamination of phenyl acetylene with aniline was carried out in toluene under reflux condition in N-2 atmosphere at 393 K. The reaction is highly regio-selective for only Markovnikoff{\textquoteright}s addition of an-tine to CC multiple bond and proceeded smoothly to completion. The reaction conditions were optimized to obtain complete conversion with respect to phenyl acetylene. Reaction data showed that the activity of the catalyst in hydroamination reaction is greater at higher reaction temperatures and nonpolar solvents and NZ pressure promotes the reaction drastically. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {alkyne, Aniline, Catalyst, hydroamination, K-10 montmorillonite clay, phenyl acetylene}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.04.022}, author = {Joseph, Trissa and Shanbhag, G. V. and Halligudi, Shivappa B.} } @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 { ISI:000249564600009, title = {Copper(II) ion exchanged A1SBA-15: a versatile catalyst for intermolecular hydroamination of terminal alkynes with aromatic amines}, journal = {Journal of Catalysis}, volume = {250}, number = {2}, year = {2007}, month = {SEP}, pages = {274-282}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The hydroarnination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. AISBA-15 was synthesized by isomorphous substitution of aluminum into the framework of SBA-15, which induces the Bronsted acid sites, and these were exchanged with metal ions such as Cu2+, Zn2+, and Pd2+. The catalysts were characterized by XRD, N-2-sOrption, SEM, TEM, acidity measurements by FT-IR pyridine adsorption, H-2-TPR, (27)AI MAS NMR, and Si-29 MAS NMR. Hydroamination of phenylacetylene (PhAc) with 2,4-xylidine has been used as a test reaction, which gave N-(1-phenylethylidene)-2,4-dimethylaniline with no byproduct formation. CuAlSBA-15 and CuAIMCM-41 showed around three times greater activity in hydroamination of PhAc compared with Cu-clay and Cu-beta, due to the moderate Lewis acidity of Cu2+ present in mesoporous supports. The performance of the CuAlSBA-15 was also determined with different alkynes and amines to evaluate the catalyst{\textquoteright}s general applicability in hydroamination reactions. (c) 2007 Elsevier Inc. All rights reserved.

}, keywords = {A1SBA-15, addition, alkyne, Amine, Copper catalyst, heterogeneous, hydroamination, ion exchange, Mesoporous}, issn = {0021-9517}, doi = {10.1016/j.jcat.2007.06.007}, author = {Shanbhag, Ganapati V. and Joseph, Trissa and Halligudi, Shivaraj B.} } @article { ISI:000255189100003, title = {Chemoselective synthesis of beta-amino acid derivatives by hydroamination of activated olefins using AISBA-15 catalyst prepared by post-synthetic treatment}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {284}, number = {1-2}, year = {2008}, month = {APR}, pages = {16-23}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

beta-Amino acid derivatives have a wide variety of applications viz. in the synthesis of peptide analogues, precursor for amino alcohols, optically active amino acids, lactums and diamines. Chemoselective anti-Markovnikov hydroamination reaction of activated olefins was effectively used to synthesize beta-amino acid derivatives using AlSBA-15 and AlMCM-41 catalysts. These catalysts with different Si/Al ratios were synthesized by isomorphous substitution of aluminium into the framework of SBA-15, which induces the Bronsted and Lewis acid sites. The structural integrity of the catalysts was established by characterizing with XRD, N-2-sorption, TEM, NH3-TPD Al-27 MAS NMR and Si-29 MAS NMR techniques. Hydroamination of ethyl acrylate with aniline was used as a test reaction, which gave N-[2-(ethoxycarbonyl)ethyl] aniline with high selectivity. The performance of AlSBA-15 catalyst was also determined with different acrylates and amines to know the general applicability of the catalyst in hydroamination reactions. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {acrylate, activated olefin, addition, AlMCM-41, AlSBA-15, Amine, beta-amino acid, Catalyst, hydroamination, Mesoporous}, issn = {1381-1169}, doi = {10.1016/j.molcata.2007.12.025}, author = {Shanbhag, Ganapati V. and Kumbar, S. M. and Halligudi, Shivaraj B.} } @article { ISI:000345975300012, title = {Titania nanoparticles stabilized HPA in SBA-15 for the intermolecular hydroamination of activated olefins}, journal = {ChemCatChem}, volume = {6}, number = {12}, year = {2014}, month = {DEC}, pages = {3347-3354}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

A liquid phase hydroamination (HA) of alpha,beta-ethylenic compounds with amines was investigated with TiO2 nanoparticles stabilized 12-tungstophosphoric acid (TPA) in SBA-15. The catalysts were prepared by wet impregnation of TPA/TiO2 nanoparticles into the SBA-15 and calcined at different temperatures. The characterization results reveal that the textural properties and the acidity of the prepared catalysts can be finely controlled with the simple adjustment of the calcination temperature and the structure of the support, decorated with the TiO2 and TPA nanoparticles, was intact even after the modification. The prepared catalysts were investigated for HA of ethyl acrylate with different aromatic and aliphatic amines over a wide range of reaction conditions to optimize the yield and the selectivity of product. It was found that this process is 100\% atom efficient and the catalytic performance depended significantly on the loading of TPA over the catalyst and the calcination temperature. Under optimized reaction conditions, the best catalyst, 15 wt\% TPA/22.4 wt\% TiO2/SBA-15 calcined at 1123 K, offered the highest conversion of p-ethylaniline (70\%) with 100\% chemo-selectivity to the anti-Markovnikov product, i.e., the mono-addition product. The reaction was heterogeneously catalyzed and no contribution from leached TPA into the reaction was observed.

}, keywords = {heteropoly acids, hydroamination, mesoporous materials, nanocatalysts}, issn = {1867-3880}, doi = {10.1002/cctc.201402449}, author = {Sawant-Dhuri, Dhanashri and Balasubramanian, Veerappan V. and Ariga, Katsuhiko and Park, Dae-Hwan and Choy, Jin-Ho and Cha, Wang Soo and Al-deyab, Salem S. and Halligudi, Shivappa B. and Vinu, Ajayan} } @article {48405, title = {Silver dependent enantiodivergent gold(i) catalysed asymmetric intramolecular hydroamination of alkenes: a theoretical study}, journal = {Catalysts}, volume = {12}, year = {2022}, month = {NOV}, pages = {1392}, type = {Article}, abstract = {

We report a theoretical study of the first silver-dependent enantiodivergent gold-catalysed reaction. The combination of a single chiral binuclear gold(I) chloride complex and silver perchlorate catalyses the asymmetric intramolecular hydroamination of alkenes and affords both enantiomers of the products by applying a simple solvent change from toluene to methanol. A gold-silver chloride adduct that occurs only in methanol appears to control the enantioinversion. If one gold atom coordinates and activates the alkene moiety, the other gold is included in an adduct with silver chloride, which coordinates a methanol solvent molecule and further interacts with the amine function. If the use of toluene implies free anions and affords (S)-enantiomer, methanol allows a proximal interaction with the amine, leads to an opposite stereodifferentiation of the two diastereomeric intermediates during the final protodeauration step and results in the (R)-enantiomer.

}, keywords = {alkene, enantiodivergent catalysis, Gold, hydroamination, Silver}, doi = {10.3390/catal12111392}, author = {Dixit, Ruchi and Sharma, Himanshu and Agbossou-Niedercorn, Francine and Vanka, Kumar and Michon, Christophe} }