24090-98-0Relevant articles and documents
Sequential [3+2] annulation reaction of prop-2-ynylsulfonium salts and hydrazonyl chlorides: Synthesis of pyrazoles containing functional motifs
Jia, Tingting,Liu, Shourong,Shao, Jiaan,Shi, Tao,Wu, Zhaoxiao,Zeng, Linghui,Zhang, Chong,Zhang, Jiankang,Zhu, Huajian,Zhuang, Rangxiao
supporting information, p. 8460 - 8463 (2021/09/08)
A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently. This journal is
Facile One-Pot Transformation of Primary Alcohols into 3-Aryl- and 3-Alkyl-isoxazoles and -pyrazoles
Kobayashi, Eiji,Togo, Hideo
, p. 3723 - 3735 (2019/09/30)
Various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylisoxazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, NH 2 OH, and then NCS, followed by reaction with alkynes in the presence of Et 3 N. Similarly, various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylpyrazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, PhNHNH 2, and then NCS and decyl methyl sulfide, followed by reaction with alkynes in the presence of Et 3 N. Thus, both 3-aryl- and 3-alkylisoxazoles, and 3-aryl- and 3-alkylpyrazoles could be prepared from readily available primary alcohols in one pot under transition-metal-free conditions.
Fast hydrazone reactants: Electronic and acid/base effects strongly influence rate at biological pH
Kool, Eric T.,Park, Do-Hyoung,Crisalli, Pete
supporting information, p. 17663 - 17666 (2014/01/06)
Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates. Similarly, tests of a hydrazine with a neighboring carboxylic acid group show that it also reacts at an accelerated rate. Rate constants for the fastest carbonyl/hydrazine combinations are 2-20 M-1 s-1, which is faster than recent strain-promoted cycloaddition reactions.
