1260101-57-2Relevant academic research and scientific papers
Aza-enamines XI.1 vinylogous aza-enamines as neutral d 3-nucleophiles: Aminomethylations of N,N-dimethylhydrazones of α,β-unsaturated aldehydes
Grabowski, Matthias T.,Nowosinski, Karol,Lentz, Dieter,Brehme, Rainer,Schalley, Christoph A.
experimental part, p. 3556 - 3568 (2010/11/21)
N,N-Dimethylhydrazones of propenal- and 2-methyl-propenal and their derivatives and homologues (vinylogous aza-enamines) were allowed to react with N,N-dimethylformiminium chloride in moisture-free dimethylformamide to yield singly, doubly, and even triply aminomethylated products. They can be easily separated and characterized as crystalline hydrochlorides. The reaction takes place at the ω-position of the π-system. This is a consequence of the conjugative interaction of the electron-donating aminohydrazone group with the double bond system in analogy to the enamines. The formation of dialkylhydrazones from unsaturated aldehydes thus causes the umpolung of the formerly electrophilic d3-building blocks into a nucleophile. Depending on the reaction conditions and confirmed by crystal structures and 2D NMR experiments, control can be exerted over the degree of substitution: Up to trisubstituted products were obtained for the 2-methylpropenal derivative. The hydrochlorides can be easily deprotonated to yield the free aminohydrazone bases. The back-conversion of the aminohydrazones into the corresponding amino aldehydes is possible under acidic conditions. Georg Thieme Verlag Stuttgart.
