No abstract

A new approach toward chromeno[4,3‐b]pyrrol‐4(1H)‐ones, by annulation of 4‐phenylaminocoumarins with β‐nitroalkenes, is reported and its conditions were optimized. The transformations under the fine‐tuned conditions took place under promotion by TsOH.H2O, in the absence of solvent. The scope and limitations of the process were explored, by systematic modification of two diversification points. A reaction mechanism, triggered by a Michael addition of the nitrogen moiety of the 4‐phenylaminocoumarins to the β‐nitroalkene, was also proposed. Further functionalization of a selected tricycle was performed; the photophysical (UV and fluorescence spectra; 1O2 generation) and electrochemical (cyclic voltammetry) properties of some heterocycles were studied.

No abstract

BuLi‐mediated Wittig—Horner reactions of 4‐formylpyrazoles with arylthiophosphonates result in a synthesis of E/Z‐mixtures of 4‐vinyl sulfide derivatives.