Catalyst and solvent switched divergent C-H functionalization: oxidative annulation of N-aryl substituted
Siddi Ramulu Meesa1, Praveen Kumar Naikawadi1, Kishan Gugulothu1
1Department of Chemistry, Osmania University, Hyderabad-500 007, India. shivakumarkota@yahoo.co.in shivakumarkota@osmania.ac.in.
Abstract:
The development of site-selective C-H functionalizations/annulations is one of the most challenging practices in synthetic organic chemistry particularly for substrates bearing several similarly reactive C-H bonds. Herein, we describe catalyst and solvent controlled ortho/peri site-selective oxidative annulation of C-H bonds of N-aryl substituted quinazolin-4-amines with internal alkynes. The ortho C-H selective annulation was observed using Pd-catalyst in DMF to give indole-quinazoline derivatives, while, Ru-catalyst in PEG-400 favoured the peri C-H bond annulation exclusively to furnish pyrido-quinazoline derivatives.
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