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Ru(II)-Catalyzed Divergent C-H Annulations of Propargyl Cyclic Carbonates
Debasish Jana1, Geetanjali S Sontakke1, Chandra M R Volla1
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Abstract:
Herein, we report Ru(II)-catalyzed divergent annulations of propargyl cyclic carbonates with arylpyrazolidinones via C-H bond activation. The combination of base and solvent was pivotal in dictating the reaction pathway, enabling selective access to either (4+3) or (3+2) annulated nitrogen-containing heterocycles with high regioselectivity. While AgOAc in DCM promoted the three-center reactivity of propargyl carbonate, NaOAc in toluene induced two-center reactivity. Both protocols exhibited broad substrate scope and excellent functional group tolerance. The synthetic utility was demonstrated through late-stage modification of biologically active derivatives, gram-scale synthesis, and postfunctionalizations of the products to other valuable motifs.
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