Kishor Chandra Bharadwaj

Intramolecular Morita–Baylis–Hillman and Rauhut–Currier reactions. A catalytic and atom economic route for carbocycles and heterocycles

Intramolecular Morita–Baylis–Hillman and Rauhut–Currier reactions are important tools which have constantly grown over several years. This review summarizes and highlights their various aspects such as development of activated alkenes, electrophiles and catalysts both in achiral and chiral fashion, use of non conventional electrophiles, applications in total synthesis. Selected miscellaneous reports of internal promoters, cycloadditions, and non conventional routes for IMBH adduct have also been presented, along with future projections.

Ligand-free palladium-catalyzed facile construction of tetra cyclic dibenzo[b,h][1,6]naphthyridine derivatives: domino sequence of intramolecular C–H bond arylation and oxidation reactions

A ligand-free Pd-catalyzed approach has been developed for the synthesis of dibenzo-fused naphthyridines. The reaction involves a one-pot domino sequence of reactions involving C–H functionalisation and oxidation. The reaction was applicable to a wide range of substrates, giving the required product. Further fluorescence studies were performed where the Stokes shift was found to be dependent on the polarity of the solvent.

Pd catalyzed facile synthesis of cyclopenta[b]quinolin-1-one via sequential Sonogashira coupling and annulation. An unusual mode of ring closure, using sulphur as a soft nucleophile

Pd mediated one pot sequential Sonogashira coupling followed by annulation using o-alkynyl aldehyde is reported. Contrary to the established modes of ring closures, an unusual mode of the initial attack of sulphur across the triple bond occurs leading to a cascade of reactions. The protocol requires just single column chromatography, delivering cyclopenta[b]quinolin-1-one in high yields. Furthermore chemoselective transformations were carried out across annulated precursors.

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

Summary The Morita–Baylis–Hillman reaction of acrylamide, as an activated alkene, has seen little development due to its low reactivity. We have developed the reaction using isatin derivatives with acrylamide, DABCO as a promoter and phenol as an additive in acetonitrile. The corresponding aza version with acrylate and acrylonitrile has also been developed resulting in high product yields.

Alkaloid group of Cinchona officinalis: structural, synthetic, and medicinal aspects

Abstract Of the various natural products isolated so far, cinchona alkaloids hold the supreme position for their various medicinal, synthetic, and catalytic applications. The diverse array of structural features studded with a complete spectrum of biological properties makes them a valuable class of natural products. This chapter summarizes their isolation and structural aspects. Subsequently, important synthesis followed by medicinal properties has been discussed.