Celite‐Polyaniline supported palladium catalyst for chemoselective hydrogenation reactions

Abstract

Polyaniline coated on particles of celite is used as support to load palladium catalyst. This heterogenized Celite•PANI•Pd system, is used as an efficient catalyst for chemoselective hydrogenation reactions. The catalyst is characterized by usual spectral, analytical techniques and studied for hydrogenation reactions at ambient conditions. The mild reaction conditions allow the control over the reactions and excellent selectivity is achieved in number of conversions. Hydrogenation of a carbon–carbon double bond was favored over other polar π‐bond systems, while labile functional groups such as benzyl ether, benzyl esters, cyano, nitro and halogen remained unaffected. Primary amines were converted to N,N‐dimethyl amines with formaldehyde, the double bond of coumarin was selectively hydrogenated without opening of the lactone functionality.

Continuous flow hydrogenation with Pd complexes of pyridine‐benzotriazole ligands

“…The samples were incorporated with KBr and pressed into a pellet. 1 H NMR spectra were measured on Agilent DDR2 400-MHz spectrometer using TMS as the internal standard. Thermogravimetric/ differential thermal analyses were performed on a Perkin Elmer Diamond TG/DTA instrument.…”

“…Yield: 81%; FT-IR (KBr): ν 3445 (broad), 3333 (s), 1617 (s), 1576 (s), 1523 (s), 1452 (m), 1324 (s), 1270 (s), 1158 (s), 744 (s) cm À1 . 1…”

“…This supports the binding of the metal to the pyridine nitrogen. 1 H NMR and 13 C NMR of PyrNHCH 2 Bt-Pd are given in Figures S11 and S12, respectively.…”

“…The organic phase was dried with sodium sulfate, and the solvent was evaporated under vacuum to give the product. Yield: 92%; FT-IR (KBr): ν 1706 (s), 1593 (m), 1484 (m), 1450 (m), 1367 (m), 1217 (s), 1045 (s), 742 (s) cm À1 ; 1…”

“…Heterogeneous catalytic hydrogenation (HCH) has wide range application area [1][2][3][4][5][6][7][8] in different disciplines. Thus, synthesis of new and effective heterogeneous catalysts and efficiency investigation of these catalysts on various organic molecules by cheaper, environmentally compatible and rapid methods are among the issues that remain important today.…”