Synthesis of novel boron chelate complexes and proposed mechanism of new rearrangement

•A series of novel boron azo chelate complexes were synthesized.•A new rearrangement mechanism was proposed.•The structure was characterized by single crystal X-ray analysis.

We synthesized novel boron chelate complexes by the reaction of pyrazoline derivatives and boron trifluoride diethyl etherate followed by a new rearrangement. The structures of the compounds were characterized by IR, NMR and HRMS, especially, a typical compound 3c was confirmed by X-ray single crystal analysis. We proposed a mechanism of the rearrangement. Moreover, the absorption and fluorescence spectroscopy of these compounds were measured.

Graphical abstractA series of boron chelate complexes were synthesized and a mechanism of the rearrangement was proposed.Figure optionsDownload full-size imageDownload as PowerPoint slide