Lewis-base adducts of 9,10-dihydro-9,10-diboraanthracene: ditopic hydroboration reagents and a B-N analogue of triptycene

The dimethyl sulfide, pyridazine, or pyrazolide adducts of 9,10-dihydro-9,10-diboraanthracene are potent hydroboration reagents for terminal alkynes; the 1,2-diazene derivatives possess a paddle-wheel structure and are stabilised towards hydrolysis.