Carbon–Carbon Bond Cleavage Reaction: Synthesis of Multisubstituted Pyrazolo[1,5‑<i>a</i>]pyrimidines

A new carbon–carbon bond cleavage reaction was developed for the efficient synthesis of multisubstituted pyrazolo­[1,5-<i>a</i>]­pyrimidines. This base induced reaction of 1,3,5-trisubstituted pentane-1,5-diones and substituted pyrazoles afforded good yields of the pyrazolo­[1,5-<i>a</i>]­pyrimidines

Ru(II)-Catalyzed and Ligand-Controlled C–H Activation and Annulation via 1,2-Phenyl Shift: Synthesis of Quaternary Carbon-Centered Pyrimidoindolones

A novel Ru­(II)-catalyzed C–H activation and annulation reaction of <i>N</i>-arylpyrazol-5-ones and diaryl/arylalkyl-substituted alkynes is developed. Unlike the reported metal-catalyzed C–H activation and annulation reactions, in the present bidentate amine-ligand controlled C–H activation and annulation reaction, the annulation occurs via a 1,2-aryl shift to afford quaternary carbon-centered pyrimidoindolones