Reaction of a Trifluoromethylated N-Monosubstituted Hydrazone with α,β-Ethenyl Ketones: A Novel Synthesis of Substituted Pyrazolidines and Pyrazolines - Xie, Haibo; Zhu, Jiangtao; Chen, Zixian; Li, Shan; Wu, Yongming (Synthesis, 2011)