Abstract:
The thesis is mainly based on the development and application of nitrogen directed C‒H
activation methodologies in the synthesis of natural products, new scaffolds, and drugs. We have
successfully developed Pd‒catalyzed “olefin amidation/C‒H activation” protocol for the synthesis of (±)-8-
oxocanadine and (±)-8-oxostylopine protoberberine alkaloids and formal synthesis of the drug
tetrahydropalmatine. Quinazolinone directed C(sp2)‒arylation and C(sp3)‒acetoxylation protocols have
also been developed for the synthesis of new quinazolinones using Pd-catalysis. Novel Ru‒catalyzed
regioselective cascade annulation of acrylamides with 2-alkynoates via aza-Michael/C‒H activation
sequence for the synthesis of various 6-oxo nicotinic acid esters has been developed. The regioselectivity is
confirmed by silver mediated protodecarboxylation of the corresponding 6-oxo nicotinic acid to furnish 2-
pyridone. The detection of ruthenacycle intermediate (HRMS) in the reaction mixture and the nonreactivity
of the phenyl and t-butyl substituted 2-alkynoates under the developed protocol suggests a plausible
mechanism and involvement of allene intermediates.
