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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.

A polyaniline-anchored palladium catalyst was prepared and screened for coupling reactions of aryl halides. The robust and recyclable catalyst was effective in Mizoroki-Heck and Suzuki-Miyaura reactions of aryl bromides and aryl iodides. The catalyst system was further employed for one-pot Wittig-Heck and Wittig-Suzuki combinations to build conjugated compounds in good conversions.Scheme 5. Compounds prepared from the Suzuki-Miyaura reaction with PANI-Pd catalyst and PhB(OH) 2 or ArB(OH) 2 . Scheme 4. PANI-Pd-catalysed Suzuki-Miyaura reaction. Scheme 6. One-pot Wittig-Heck reaction catalysed by PANI-Pd. Scheme 7. Compounds prepared from the one-pot Wittig-Heck reaction with PANI-Pd catalyst (all from ArI).Scheme 8. One-pot Wittig-Suzuki reaction catalysed by PANI-Pd.Polyaniline-Pd catalysed Heck, Suzuki and one-pot coupling reactions

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A range of benzochalcogendiazole-based small molecules are synthesized following various C–C coupling methodologies and studied for their photo-physical properties and structural aspects.

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Polyaniline was heterogenized on celite particles and used as a support for palladium metal ions. The catalyst was found to be effective in Suzuki–Miyaura and its one-pot aldol reactions.