Regioselective Alkylations of Cyclic 1,3-Diketonesvia Metalated Dimethylhydrazones
摘要:
Cyclic 1,3- diketones 1 are transformed into their 2,2-dimethylhydrazones 2, which can be alkylated regioselectively at different positions after mono-, di-, tri-, and tetrametalation. Monometalated C-2 unsubstituted hydrazones afford C-2 and N-alkylation, monometalated C-2 substituted hydrazones afford only C-2 alkylation. The regioselectivity of the alkylation of the polymetalated hydrazones follows Hauser's rule according to the sequence: NH- > C-4 Ha > C-5 > C-4 Hb. Hydrolysis of the product hydrazones 3-5 afforded mono-and polyalkylated 1,3- diketones 7 in good yields.
Synthesis of α,β-Dicarbonylhydrazones by Aerobic Manganese-Catalysed Oxidation
作者:Carlos J. Carrasco、Francisco Montilla、Eleuterio Álvarez、Agustín Galindo
DOI:10.1002/adsc.201800601
日期:2018.10.4
practical, simple, and efficient manganese‐catalysed oxidation of C(sp2)−H bond in readilyavailable β‐carbonylenehydrazine under aerobic conditions has been developed. This protocol exhibits a wide range of functional group tolerance in β‐carbonylenehydrazines to afford α,β‐dicarbonylhydrazones. Experimental and theoretical results suggest that the reaction very likely proceeds through a radical pathway
Regioselective alkylation of dianions of cyclic 1.3-diketones via their monodimethylhydrazones. Synthesis of C-4 substituted cyclic 1.3-diketones
作者:Ayhan S. Demir、Dieter Enders
DOI:10.1016/s0040-4039(00)99560-1
日期:1989.1
Cyclic 1.3-diketones are transformed into the corresponding monodimethylhydrazones, which can be alkylated regioselectively at C-4 via dianions with various alkyl halides.
Reactions of cyclic enhydrazinoketones with arylidene derivatives of malononitrile. Synthesis of fusedN-substituted 1,4-dihydropyridines
作者:B. V. Lichitsky、V. N. Yarovenko、I. V. Zavarzin、M. M. Krayushkin
DOI:10.1007/bf02495769
日期:2000.7
A new method for the synthesis of fused N-amino-1,4-dihydropyridines was proposed. The method is based on the addition of cyclic enhydrazinoketones to arylidenemalononitriles. The structures of the compounds synthesized were studied using H-1 NMR spectroscopy.
Demir, Ayhan S.; Enders, Dieter, Zeitschrift fur Naturforschung, B: Chemical Sciences, 1989, vol. 44, # 7, p. 834 - 838