Deboronation of C-substituted ortho- and meta-closo-carboranes using ''wet'' fluoride ion solutions

Hydrated tetrabutylammonium fluoride has been found to be more effective than the anhydrous salt as a reagent for the conversion of ortho and meta closo-carborane derivatives, R'R '' C2B10H10 into nido-carborane anions, [R'R '' C2B9H10](-), allowing access to a number of new nido-carborane derivatives difficult to prepare, or inaccessible. using other deboronating reagents, notably the meta-carborane derivatives, [7,9-R'R ''-7,9-C2B9H10](-) [Bu(4)N](+) (R' = 4-HOC6H4, 4-O2NC6H4; R '' = H and R' = R '' = 4-PhOC(6)H(4), 4-O2NC6H4, 2-C5H4N, 4-H2NC6H4). Experiments with the bis(p-bromophenyl-ortho-carboranyl) benzene, 1,4-[4-BrC6H4CB10H10C]2C6H4, carried out to determine the quantity of tetrabutylammonium fluoride needed to deboronate both cages, afforded the salt 1,4-[7-(4-BrC6H4)C2B9H10]2C6H42- [Bu(4)N(+)](2).