HFIP-promoted one-pot synthesis of (Pyrazolo[1,5-a]pyrimidinyl)(indolyl)methanes using Rongalite as a C1 synthon under mild conditions

In this report, we established an efficient synthetic strategy for the construction of heterodiarylmethanes via the coupling of pyrazolo[1,5- a ]pyrimidine and indole using rongalite as methylene source under metal-free conditions at room temperature in HFIP solvent. Rongalite was used as a relatively benign and metal-free reagent and cost-effective C1 synthon. The present methodology offers a total of 21 examples, moderate to good yields of products and easy operations under the mild conditions. The newly synthesized molecules represent a unique class of functionalized heterocycles with potential biological relevance.