Recent Advances in the Synthesis of Functionalized Pyrazolo[1,5-a]pyrimidines via C–H Functionalization

Abstract Recent developments in the synthesis of functionalized pyrazolo[1,5-a]pyrimidines through C–H functionalization have been summarized in this account, covering the synthesis of 3-halo, 3-nitro, 3-formyl, 3-acetyl, 3-sulfenyl, 3-selenyl, and 3-thiocyanato pyrazolo[1,5-a]pyrimidines and bis(pyrazolo[1,5-a]pyrimidin-3-yl)methanes. The main focus highlights the utilization of sustainable conditions in designing the protocols. Mechanistic aspects of these protocols have also been discussed in detail. 1 Introduction 2 Discussion 2.1 Synthesis of 3-Halo Pyrazolo[1,5-a]pyrimidines 2.2 Synthesis of 3-Nitro Pyrazolo[1,5-a]pyrimidines 2.3 Synthesis of 3-Formyl Pyrazolo[1,5-a]pyrimidine 2.4 Synthesis of 3-Acetyl Pyrazolo[1,5-a]pyrimidines 2.5 Synthesis of 3-Sulfenyl Pyrazolo[1,5-a]pyrimidines 2.6 Synthesis of 3-Selenyl Pyrazolo[1,5-a]pyrimidines 2.7 Synthesis of 3-Thiocyanated Pyrazolo[1,5-a]pyrimidines 2.8 Synthesis of Bis(pyrazolo[1,5-a]pyrimidinyl)methanes 3 Conclusions and Outcome