75981-12-3Relevant academic research and scientific papers
Regioselective Decarboxylative Cycloaddition Route to Fully Substituted 3-CF3-Pyrazoles from Nitrilimines and Isoxazolidinediones
Tian, Yu-Chen,Li, Jun-Kuan,Zhang, Fa-Guang,Ma, Jun-An
supporting information, p. 2093 - 2097 (2021/03/15)
1,4-Diaryl-5-carboxamido substituted 3-trifluoromethylpyrazoles are obtained with exclusive regioselectivity under transition-metal-free conditions. This decarboxylative [3+2] cycloaddition protocol was enabled by employing trifluoromethyl nitrilimines as 1,3-dipoles, and isoxazolidinediones as CO2-masked alkynyl dipolarophiles. The applicability of this method is further manifested by its compatibility with difluoromethyl, alkyl, aryl, and heteroaryl nitrilimines, as well as the preparation of 4-carboxylic amido analogue of drug Celebrex. (Figure presented.).
A [4 + 3] Annulation Reaction of aza- o-Quinone Methides with Arylcarbohydrazonoyl Chlorides for Synthesis of 2,3-Dihydro-1 H-benzo[ e][1,2,4]triazepines
Guo, Zhenyan,Jia, Hao,Liu, Honglei,Wang, Qijun,Huang, Jiaxing,Guo, Hongchao
supporting information, p. 2939 - 2943 (2018/05/28)
An unprecedented [4 + 3] annulation reaction of aza-ortho-quinone methides with arylcarbohydrazonoyl chlorides has been achieved under mild conditions. The annulation underwent a sequential conjugate addition/intramolecular annulation/rearrangement, providing a useful method for the synthesis of biologically interesting 2,3-dihydro-1H-benzo[e][1,2,4]triazepine.
Synthesis of Spirobidihydropyrazole through Double 1,3-Dipolar Cycloaddition of Nitrilimines with Allenoates
Liu, Honglei,Jia, Hao,Wang, Bo,Xiao, Yumei,Guo, Hongchao
supporting information, p. 4714 - 4717 (2017/09/23)
The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.
[3+3]-cycloaddition of donor-acceptor cyclopropanes with nitrile imines generated in situ: Access to tetrahydropyridazines
Garve, Lennart K. B.,Petzold, Martin,Jones, Peter G.,Werz, Daniel B.
supporting information, p. 564 - 567 (2016/02/18)
Donor-acceptor cyclopropanes are reacted under the influence of a Lewis acid with hydrazonyl chlorides to afford tetrahydropyridazines. Formally, this transformation can be regarded as a [3 + 3]-cycloaddition of three-membered rings and nitrile imines generated in situ. This efficient method provides fast access to a variety of structurally diverse pyridazine derivatives. The structure of a typical product was confirmed by X-ray crystallography.
Oxidation of Ketone and Aldehyde Hydrazones, Oximes, and Semicarbazones and of Hydroxylamines and Hydrazo-compounds, using Benzeneselenic Anhydride
Barton, Derek H. R.,Lester, David J.,Ley, Steven V.
, p. 1212 - 1217 (2007/10/02)
Benzeneseleninic anhydride (1; BSA) is an effective reagent for the mild regeneration of the carbonyl group from ketone phenylhydrazones, p-nitrophenylhydrazones, tosylhydrazones, oximes, and semicarbazones at 40-50 deg C.Tosylhydrazones and oximes of aldehydes are also readily converted into the parent aldehyde.The phenylhydrazone and p-nitrophenylhydrazone derivatives of aldehydes afford ketoazo-compounds.The ketoazo-species could also be prepared by oxidation of the corresponding hydrazide with compound (1).Both aromatic and aliphatic hydrazo-compounds and hydroxylamines can be oxidised to azo- and nitrozo-derivatives respectively.
