Yang, Mengchen published the artcileHighly enantioselective Michael addition of pyrazolin-5-ones to nitroolefins catalyzed by cinchona alkaloid derived 4-methylbenzoylthioureas, SDS of cas: 14580-22-4, the publication is Chirality (2018), 30(9), 1096-1104, database is CAplus and MEDLINE.
Cinchona alkaloid-derived (4-methyl/nitro)benzoylthioureas were synthesized, which smoothly catalyzed the asym. Michael addition of pyrazolin-5-ones to nitroolefins. The results showed that electronic effects of substituents in the benzene ring of benzoylthioureas have subtle influences on their catalytic abilities and electron donating Me group was favored than electron withdrawing nitro group. Preliminary Hartree-Fock calculations revealed that in the catalytic cycle, hydrogen bond energies of the complex formed with 4-methylbenzoylthioureas were about 0.19 to 1.56 kcal/mol higher than with the corresponding 4-nitrobenzoylthioureas. 4-Methylbenzoylthioureas were identified as the most effective catalysts that promoted asym. Michael addition of pyrazolin-5-ones to nitroolefins to give the S- or R-products with high enantioselectivities.
Chirality 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 C4H10BBrO2, SDS of cas: 14580-22-4.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics