TEMPO-Mediated Aza-Diels–Alder Reaction: Synthesis of Tetrahydropyridazines Using Ketohydrazones and Olefins
作者:Xiu-Long Yang、Xie-Xue Peng、Fei Chen、Bing Han
DOI:10.1021/acs.orglett.6b00702
日期:2016.5.6
facile, and efficient method for the synthesis of tetrahydropyridazines by a one-pot tandem reaction of easily accessible ketohydrazones and olefins in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has been successfully developed. The reaction involves the initial generation of azoalkenes from direct oxidative dehydrogenation of ketohydrazones using TEMPO as the commercially available
and diastereoselective synthesis of 4-nitropyrazolidines is presented. Asymmetric hydrogen-bonding activation of nitro-olefins facilitated the 1,3-dipolar cycloaddition with hydrazones, affording opticallyactive 4-nitropyrazolidines containing three continuous stereogenic centers as a single diastereomer in up to 99% ee. Furthermore, it is demonstrated that the opticallyactive 4-nitropyrazolidines
N-alkenyl-3,5-pyrazolidinediones from ketone hydrazones, PCl3 and malonic acid
作者:Graziano Baccolini、Michele Gianelli
DOI:10.1016/0040-4020(95)00550-r
日期:1995.8
The title compounds 3, a new series of 3,5-pyrazolidinediones, have been synthesized at room temperature by a one-pot reaction between ketone hydrazone 1, PCl3 and malonic acid. Changing the order of addition of reagents, or their simultaneous addition, gave identical results. In all me procedures the yields are good and in the cases a,b,c and g the E-alkenyl isomer was obtained as the exclusive isomer. A dual mechanism which depends on the order of addition of the reactants is hypothesised.
El-Abadelah, M. M.; Hussein, A. Q.; Abushamleh, A. S., Journal fur praktische Chemie (Leipzig 1954), 1991, vol. 333, # 1, p. 61 - 65
作者:El-Abadelah, M. M.、Hussein, A. Q.、Abushamleh, A. S.