14492-08-1Relevant academic research and scientific papers
Continuous Flow α-Arylation of N,N-Dialkylhydrazones under Visible-Light Photoredox Catalysis
Vega, Juan A.,Alonso, José Manuel,Méndez, Gabriela,Ciordia, Myriam,Delgado, Francisca,Trabanco, Andrés A.
supporting information, p. 938 - 941 (2017/02/26)
The first direct α-arylation of aldehyde-derived N,N-dialkylhydrazones with electron deficient aryl and heteroaryl cyanides under visible-light photoredox catalysis has been developed. Structurally complex α,α′-diaryl-N,N-cycloalkylhydrazones were obtaine
Reaction of the lithio-derivative of methoxyallene with hydrazones. Part 1: Synthesis and transformation of α-allenyl hydrazines
Breuil-Desvergnes, Valérie,Goré, Jacques
, p. 1939 - 1950 (2007/10/03)
The lithio-derivative of methoxyallene reacts with aldehyde hydrazones leading to expected α-allenyl hydrazines when ether is the solvent of the reaction. The yields are good as well as the diastereoselectivity observed in the case of SAMP-hydrazones. These hydrazines are cleanly transformed to N-dialkylamino-3-methoxy-3-pyrrolines when they are reacted with n-BuLi in THF. These compounds are sometimes accompanied by the isomeric 4-methyl azetidines. The N-dialkylamino-3-methoxy-3-pyrrolines are transformed to 3-methoxy-3-pyrrolines by hydrogenolysis of the nitrogen-nitrogen bond, to 3-alkoxy-pyrroles by treatment with a peracid and to 3-amino-pyrroles by acidic migration of the dialkylamino group. In the case of SAMP-hydrazines, the obtained 3-methoxy-3-pyrrolines have a high enantiomeric purity. Lastly, attempts to prepare α-hydrazino-esters (and subsequently α-amino-esters) by ozonolysis of the allenyl moiety failed due to the formation of a methyl glyoxylate.
Aza-enamines, VIII. - Electrophilic Substitution reactions at the Azomethine C-Atom of Aldehyde Dialkylhydrazones: Vilsmeier Formylation and Consecutive Reactions
Brehme, Rainer
, p. 2039 - 2046 (2007/10/02)
The reaction of hydrazones 1 with the Vilsmeier reagent yields 3-phenyl-1,4,5-triaza-1,3-pentadienium salts according to their aza-enamine character.Hydrolysis of 2 gives 1-phenylglyoxal 1-dialkylhydrazones 3, which rearrange in acidic media to 1-phenylglyoxal 2-dialkylhydrazones 4.Compound 3h forms the dihydropyrroloimidazole 5 in boiling ethanol.Pyrrolotriazinium salt 6 is obtained by the reaction of 1b with the isolated Vilsmeier reagent from dimethylformamide/oxalyl chloride.
