Alkynyl Fischer Carbenes as a Platform for the Production of Difluorodiazaborinine Complexes via β-Amino-azadienes

The results of a study of the reactivities of alkynyl Fischer carbenes in the syntheses of diazaborinine derivatives 7a-i are reported. The strategy employed included the use of β-amino-α,β-unsaturated carbenes (3a–j) with different amines in order to determine the scope of a previously unknown catalytic reaction in the presence of copper salts and anilines. The reaction was highly stereoselective, yielding (Z)-isomers of the β-amino-1-azadiene framework as the main products (4a–o). As an extension of this research, the compounds 4a–o proved to be suitable precursors for the syntheses of diazaborinine scaffolds in good yields (7a-i).