A New and Efficient Method for the Preparation of Bismuthonium and Telluronium Salts Using Aryl- and Alkenylboronic Acids. First Observation of the Chirality at Bismuth in an Asymmetrical Bismuthonium Salt

Treatment of triarylbismuth difluorides with aryl- and alkenylboronic acids in the presence of BF 3 ·OEt 2 afforded tetraaryl- and alkenyltriarylbismuthonium tetrafluoroborates, respectively, while similar treatment of diphenyltellurinyl difluoride yielded the corresponding telluronium salts. The chirality at bismuth was observed for the first time from the 1 H NMR spectrum of an asymmetrical bismuthonium salt.