New reactions of N-tert-butylimines; formation of N-heterocycles by methyl radical elimination on flash vacuum thermolysis of N-benzylidene- and N-(2-pyridylmethylidene)-tert-butylamines.

Thermal reactions of N-benzylidene- and N-(2-pyridylmethylidene)-tert-butylamines (5 and 13) under FVT conditions have been investigated. Unexpectedly, at 800 °C, compound 5 yields 1,2-dimethylindole and 3-methylisoquinoline. In the reaction of 13 at 800 °C, 3-methylimidazo[1,5-a]pyridine was obtained as the major product.

Methyliminopropadienone CH3-N═C═C═C═O: photoelectron spectrum and electronic structure.

N-Methyliminopropadienone MeN═C═C═C═O 1a was generated by flash vacuum thermolysis of three 5-(aminomethylene)-1,3-dioxane-4,6-diones (Meldrum's acid derivatives). Online monitoring of the reactions permitted the recording of the UV-photoelectron spectra and the determination of the first two ionization energies of 1a as 9.0 and 12.

Are unsaturated isocyanides so different from the corresponding nitriles?

Simple unsaturated and cyclopropylic isocyanides are synthesized by an efficient and simple approach. These compounds with gradually increasing distance between the unsaturated moiety and the isonitrile group are studied by UV photoelectron spectroscopy and quantum chemical calculations, and also compared to the corresponding nitriles. The first photoelectron band of the unsaturated compounds is linked to removal of an electron from the HOMO, which corresponds to CC multiple-bond ionization in antibonding interaction with the π-isocyanide bond (in the same plane) for conjugated systems, or in antibonding interaction with the pseudo-π-CH(2) group for isolated systems.

Beta-heterosubstituted acrylonitriles--electronic structure study by UV-photoelectron spectroscopy and quantum chemical calculations.

Beta-heterosubstituted acrylonitriles correspond to the formal addition of nucleophiles on cyanoacetylene. Acrylonitriles substituted with an amino, methoxy, mercapto group, or halogeno atom have been synthesized. Rearrangements between Z and E stereoisomers or tautomerizations have been studied by NMR spectroscopy and by quantum calculations.