A Protocol for the Synthesis of CF2H‑Containing Pyrazolo[1,5‑c]quinazolines from 3‑Ylideneoxindoles and in Situ Generated CF2HCHN2
datasetposted on 01.06.2018, 23:29 by Wen-Yong Han, Jian-Shu Wang, Jia Zhao, Lin Long, Bao-Dong Cui, Nan-Wei Wan, Yong-Zheng Chen
Herein is disclosed a selective and facile approach for the construction of CF2H-containing pyrazolo[1,5-c]quinazolines from easily accessible 3-ylideneoxindoles and in situ generated CF2HCHN2. The reaction involving a [3 + 2] cycloaddition/1,3-H shift/rearrangement/dehydrogenation cascade proceeded smoothly at room temperature in the absence of catalyst and additive. Moreover, this metal-free process along with mild conditions is desirable and valuable for the pharmaceutical industry. Importantly, this reaction features a broad substrate scope, good functional group tolerance, and gram-scale synthesis.