Polyfluoroorganoboron-oxygen compounds.: 4 [1] Lithium pentafluorophenyltrimethoxyborate, Li[C6F5B(OMe)3], reactions with selected electrophiles and nucleophiles

Li[C6F5B(OMe)(3)] (1a) reacted with the electrophiles CD3C(O)CD3, CH3OD, CD3CN, CH3CN, HOC2H4OH, Br-2, and I-2 to give C6F5X (X = D, H, Br, I). The treatment of 1a with Me3SiCl or BF3 in CH2Cl2 and CCl3F or pentene resulted in C6F5B(OMe)(2) or C6F5BF2, respectively. The attempted metathesis of 1a with KF or [Bu4N]Br in CH2Cl2 led to a mixture of M[(C6F5)(2)B(OMe)(2)] (2b,c, main product) and M[C6F5B(OMe)(3)] (1b,c, minor product) (M = [Bu4N], K). Even in the presence of diethyl ether, THF, DME, or TMEDA salt 1a underwent dismutation to the diarylborate salt [Li(L)(n)][(C6F5)(2)B(OMe)(2)] (L = Et2O, THF, DME, TMEDA) and [Li(L)(n)][B(OMe)(4)]. In subsequent reactions with aqueous K[HF2] or [Bu4N][HF2] M[(C6F5)(2)B(OMe)(2)] (M = K, [Bu4N], [Li(L)(n)]) yielded K[(C6F5)(2)BF2] (4c) or [Bu4N][(C6F5)(2)BF2] (4b). The molecular structure of [Li(.)TMEDA][(C6F5)(2)B(OMe)(2)] from single crystals showed significant cation-oxygen interactions.