@article { ISI:000253382100048, title = {PdCl2(bipy) complex - an efficient catalyst for Heck reaction in glycol-organic biphasic medium}, journal = {Catalysis Today}, volume = {131}, number = {1-4}, year = {2008}, note = {4th Asia-Pacific Congress on Catalysis, Nanyang Technol Univ, Singapore, SINGAPORE, DEC 06-08, 2006}, month = {FEB}, pages = {353-359}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The Palladium complex PdCl2(bipy) (1) was found to be efficient in catalyzing the Heck reaction of aryl halides in a biphasic system comprising ethylene glycol along with an organic solvent. A proper tailoring of the organic phase ensured that the leaching of the catalyst to the organic phase was negligible. The catalyst was active for the Heck reaction of a number of olefins, aryl halides, in presence of organic and inorganic bases. The PdCl2(bipy) catalyst was stable and could be recycled for five times without any loss in activity and selectivity. A major advantage of this work is that unlike hitherto reported biphasic systems; it does not employ a water-soluble ligand to achieve biphasic catalysis. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {Biphasic catalysis, C-C coupling, Heck reaction, PdCl2(bipy) complex}, issn = {0920-5861}, doi = {10.1016/j.cattod.2007.10.043}, author = {Jagtap, Sangeeta Vijay and Deshpande, Raj Madhukar} } @article { ISI:000306193700016, title = {Kinetics of the Heck reaction in biphasic organic-ethylene glycol medium}, journal = {Reaction Kinetics Mechanisms and Catalysis}, volume = {106}, number = {2}, year = {2012}, month = {AUG}, pages = {457-473}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

PdCl2(bipy) was found to be an efficient and stable catalyst in biphasic medium (organic-glycol) for the Heck reaction. The kinetics of the Heck coupling of styrene with iodobenzene using the same catalyst was studied in a biphasic medium in a temperature range of 393-413 K. The rate was found to have a first order dependence tending to a fractional order, on the iodobenzene as well as catalyst concentration. The rate was found to have a complex dependence on the styrene concentration and passes through a maximum, showing typical substrate inhibition kinetics. The rate had a first order dependence on the base (morpholine) concentration. The trends observed for the influence of the different parameters on the activity of the catalyst are in agreement with the established mechanism for Heck reaction. An empirical rate model has been proposed to fit the observed rate data. The activation energy was found to be 72.91 kJ/mol. This is the first time that kinetic modeling of Heck reaction in a biphasic medium (organic-glycol) has been attempted.

}, keywords = {Biphasic catalysis, Heck reaction, kinetics, PdCl2(bipy) complex}, issn = {1878-5190}, doi = {10.1007/s11144-012-0437-1}, author = {Jagtap, Sangeeta Vijay and Deshpande, Raj Madhukar} } @article { ISI:000325204200090, title = {Cinnamic acid derivatives via heck reaction in an aqueous-biphasic catalytic system with easy catalyst-product separation}, journal = {Asian Journal of Chemistry}, volume = {25}, number = {15, A}, year = {2013}, month = {NOV}, pages = {8633-8637}, publisher = {ASIAN JOURNAL OF CHEMISTRY}, address = {11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA}, abstract = {

A true biphasic [aqueous-organic] system for the coupling of water soluble sodium acrylate with different aryl halides for the synthesis of cinnamic acid derivatives has been developed, employing palladium catalysts that is soluble in organic phase. Amongst them, palladacycle was found to be stable in presence of water and could be recycled for four times with no loss in the activity. Such a system facilitates easy recycle of catalyst and also the removal of the salts from the catalyst phase, ensuring high activity with respect to cumulative turn over number (TON) and turn over frequency (TOF). The reaction was facilitated by organic as well as inorganic bases. The efficiency of the catalyst, role of organic/inorganic bases on the activity is reported.

}, keywords = {Biphasic catalysis, Heck reaction, Palladacycle, Separation}, issn = {0970-7077}, author = {Jagtap, Sangeeta Vijay and Deshpande, R. M.} } @article { ISI:000318393000043, title = {True water soluble palladium-catalyzed Heck reactions in aqueous-organic biphasic media}, journal = {Tetrahedron Letters}, volume = {54}, number = {21}, year = {2013}, month = {MAY}, pages = {2733-2736}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A stable water soluble palladium catalyst has been demonstrated for the Heck reaction in a biphasic medium (water-non-polar organic solvent). Biphasic Heck reactions reported till now generally employ a non-polar solvent along with an aqueous polar water miscible organic solvent as the second phase. The efficiency of the Pd complex of TOTPS [Trisodium salt of tri-(ortho-tolyl) phosphine tri sulfonate] for the vinylation of different aryl iodides and olefins is demonstrated. The advantages of a co-solvent for this biphasic system have also been shown. The catalyst has been recycled efficiently retaining the activity with negligible loss of catalyst and without leaching of the Pd. (c) 2013 Elsevier Ltd. All rights reserved.

}, keywords = {Aqueous biphasic catalysis, C-C coupling, Heck reaction, Water-soluble catalyst}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2013.03.067}, author = {Jagtap, Sangeeta Vijay and Deshpande, Raj Madhukar} }