Water extract of pomegranate ash (WEPA), an agro waste (bio) derived novel and sustainable medium, has been developed for the Ullmann coupling of aryl halides under added base, ligand and reducing agent free palladium catalysis in open-air.

A facile palladium(II)‐porphyrin catalytic system has been developed for the Mizoroki‐Heck coupling of aryl bromides with alkyl acrylates under mild conditions. Seven different porphyrins (H2TPP, H2TpCPP, H2TpAP, H2TpTP, H2TSTpSPP, H2TmHPP and H2TmCPP) and their complexes with palladium (Pd‐TPP, Pd‐TpCPP, Pd‐TpAP, Pd‐TpTP, Pd‐TSTpSPP, Pd‐TmHPP and Pd‐TmCPP) were synthesized, and examined their catalytic role in the synthesis of alkyl cinnamates in DMF. The complex, Pd‐TSTpSPP showed better activity in the present conversion. This finding has significant advantages like operational simplicity, easy synthesis of porphyrin ligands and their complexes with palladium, utilization of safer and recyclable catalyst and high yields of Mizoroki‐Heck products.

An agro waste‐derived, ‘water extract of pomegranate ash’ (WEPA), has been utilized for the first time as a renewable medium for Pd(OAc)2‐catalysed Suzuki–Miyaura cross‐coupling at room temperature. This method offers a simple and sustainable synthesis of biaryls from aryl halides and arylboronic acids under ligand‐ and external base‐free aerobic and ambient conditions. This method has been found effective for both activated and unactivated aryl halides in the production of biaryls with moderate to nearly quantitative yields. The protocol shows high chemoselectivity over identical/similar reactive sites in aryl halides (i.e. selectivity over identical halogens or different halogens of aryl halides). This method exhibits high regioselectivity, i.e. the selective reactivity of a halogen over other identical halogens at different positions on the aromatic nucleus. Therefore, we disclose here a clean, benign, substantial chemo‐ and regioselective and highly economic alternative method for the palladium‐assisted synthesis of biaryls using an agro waste‐derived medium.

The imines of Ellman's tert-butylsulfinamides have become one of the elementary substrates for the construction of chiral precursors and complex organic molecules. This article reports a mechanochemical access to imines of chiral tert-butylsulfinamides with a variety of aldehydes using solid acid catalyst, perchloric acid-silica (HClO 4 ⋅SiO 2 ) at innocuous reaction environs. The conversion can be carried out at ambient temperature under solvent and metal-free conditions by (hand) grinding the contents in a mortar at open-air. The current protocol is highly economical, allows large-scale preparation, offers a very good to nearly quantitative yields of imines in short reaction times with no product racemization and doesn't necessitate the moisture-free conditions.

No abstract