Syntheses and solid-state structures of mono- and dialkyl(methylsulfonato)boranes

R3B reacts with MeSO3H at elevated temperature in toluene to give liquid R2 B(OSO2Me) [R = Et (la), 61%; R = Bu (Ib), 58%; R = Pr-i (Ic), 23%] and, in the case of Et3B and Bu3B, solid RB(OSO2Me)(2) [R = Et (2a), 13%; R = Bu (2 b), 11%]. As (Pr3B)-B-i is less reactive, pivalic acid must be added as cat alyst, and no formation of the disulfonatoborane is observed. Complexes la- e and 2a-b were characterised spectroscopically (IR,H-1-, C-13-, B-11-NMR), and crystal structure determinations were carried out on la, which is mono meric even in the solid state, and 2a and 2b, which are dimeric in the soli d state and have two differently bonded sulfonate groups (terminal and brid ging). (C) 1999 Elsevier Science S.A. All rights reserved.