Here, we describe the one-pot assembly of imidazo[1,2-a]pyridine and quinoxaline heterocyclic cores by the electrophilic tandem cyclization between 3,5-diaryl substituted 5-hydroxy-3-pyrrolin-2-ones and the corresponding nitrogen bis-nucleophiles.
An efficient Ru(II)-catalyzed C–H activation-based spiroannulation of benzoxazines with easily available benzoquinone and N-sulfonyl quinone monoimine has been realized, providing a straightforward strategy to access NH-containing spiropyrans.
A photochemical method for the synthesis of substituted benzo[4,5]imidazo[1,2-a]cyclopenta[e]pyridines was elaborated. It was shown that the synthesized photoproducts exist as an interconvertible mixture of tautomers in solution.
Excellent diastereoselective access to spirobenzo[b]oxepines via a [5 + 2] spirocyclization reaction of ortho-hydroxyacetophenones and 2-aroyl-1-chlorocyclopropanecarboxylates triggered by Cs2CO3 was developed.
This is the first example of the construction of harmaline-based spiropolycyclic scaffolds using harmaline-based N–C synthons and evaluation of 3cb as an anticancer agent.