A general and practical strategy for 3-trifluoromethylpyrazole synthesis is reported that occurs by the three-component coupling of environmentally friendly and large-tonnage industrial feedstock 2-bromo-3,3,3-trifluoropropene (BTP), aldehydes, and sulfonyl hydrazides. This highly regioselective three-component reaction is metal-free, catalyst-free, and operationally simple and features mild conditions, a broad substrate scope, high yields, and valuable functional group tolerance. Remarkably, the reactions could be performed on a 100 mmol scale and smoothly afforded the key intermediates for the synthesis of celecoxib, mavacoxib, SC-560, and AS-136A. Preliminary mechanism studies indicated that a 1,3-hydrogen atom transfer process was involved in this transformation.

中文翻译：

---

通过醛，磺酰肼和2-溴-3,3,3-三氟丙烯的偶联区域选择性合成3-三氟甲基吡唑。

据报道，通过环境友好的大吨位工业原料2-溴-3,3,3-三氟丙烯（BTP），醛和磺酰肼的三组分偶联，可以实现3-三氟甲基吡唑合成的通用和实用策略。这种高度区域选择性的三组分反应不含金属，不含催化剂，操作简单，具有条件温和，底物范围广，收率高和有价值的官能团耐受性。值得注意的是，反应可以在100 mmol的规模上进行，并顺利提供了塞来昔布，马伐昔布，SC-560和AS-136A合成的关键中间体。初步机理研究表明，此转化过程涉及1,3-氢原子转移过程。