Asymmetrically catalyzed synthesis method of nitropyrazole amide compound

An asymmetrically catalyzed synthesis method of a γ-nitropyrazole amide compound, wherein, in the reaction that a nitroalkane and an α,β-unsaturated pyrazole amide are employed as raw materials, a complex formed by a chiral amine oxide with a rare earth metal compound is served as a catalyst, a 4 Å molecular sieve is served as an additive, after the reaction finished, to obtain a γ-nitropyrazole amide compound, wherein,

• the structure of the nitroalkane is RCH2NO2, in which R═H, CH3, Et, or Bn;
• the structure of the α,β-unsaturated pyrazole amide compound is
• the γ-nitropyrazole amide compound has a structure of:
• the structure of the chiral amine oxide ligand is
• in which R1═C6H5, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-MeC6H4, 4-MeOC6H4, 3-BrC6H4, 3-MeC6H4, 2-BrC6H4, 2-MeOC6H4, 3,4-Cl2C6H3, 3,4-(MeO)2C6H3, 2-Furyl, 2-Thienyl, CH3, Pr, Pent, iBu, EtO, or EtOOC;
• and R2═CH3, Ph;
• R3═H, Cl, Br, or I;
• and
• n=1, or 2;
• and R═Ph—, 2,6-Me2C6H3—, 2,6-Et2C6H3—, 2,6-iPr2C6H3—, or Ph2CH—;
• and
• the rare earth metal compound is gadolinium trifluoromethanesulfonate [Gd(OTf)3], scandium trifluoromethanesulfonate [Sc(OTf)3], holmium trifluoromethanesulfonate [Ho(OTf)3], ytterbium trifluoromethanesulfonate [Yb(OTf)3], erbium trifluoromethanesulfonate [Er(OTf)3], or yttrium trifluoromethanesulfonate [Y(OTf)3].