Yang, Xiaoqun published the artcileAsymmetric Synthesis of Structurally Sophisticated Spirocyclic Pyrano[2,3-c]pyrazole Derivatives Bearing a Chiral Quaternary Carbon Center, Name: 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone, the publication is Organic Letters (2022), 24(29), 5474-5479, database is CAplus and MEDLINE.
A carbene-catalyzed enantio- and diastereoselective [2 + 4] cycloaddition reaction is developed for quick and efficient access to structurally complex multicyclic pyrano[2,3-c]pyrazole mols. I (R = Me, Ph, 1-naphthyl, etc.; R1 = H, Me, F; R2 = H, Br, F; R3 = H, Me; R4 = Me, Bn, Ac, H; R5 = Me, Ph, 2-chlorophenyl). The reaction tolerates a broad scope of substrates bearing various substitution patterns, with the multicyclic pyrano[2,3-c]pyrazole products I afforded in generally good to excellent yields and optical purities. The chiral mols. obtained from this approach have found promising applications in the development of novel bactericides for plant protection.
Organic Letters published new progress about 14580-22-4. 14580-22-4 belongs to pyrazoles-derivatives, auxiliary class Organic Pigment, name is 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone, and the molecular formula is C5H8N2O, Name: 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics