Synthesis and structural studies on fluorophenylboron azides

The fluorophenyl substituted boron chlorides (R-F)(2)BCl (3 and 4) and dich lorides RFBCl2 (6 and 7) (R-F = 2,6-F2C6H3, 2-FC6H4) were prepared using th e stannylated aryl transfer reagents (R-F)(2)SnMe2 (1 and 2). The boron azi des (R-F)(2)BN3 (8-9), [2,4,6-(CF3)(3)C6H2](2)BN3 (10) and diazides RFB(N-3 )(2) (11 and 12) were synthesized by the reaction of the corresponding boro n chlorides (R-F)(2)BCl (3 and 4), [(CF3)(3)C6H2](2)BCl (5) and RFBCl2 (6 a nd 7) with Me3SiN3. The influence of the electron withdrawing substituents on the molecular structure of these azides, is discussed. The reactions wer e also performed in the presence of pyridine yielding the adducts (R-F)(2)B N3.py and RFB(N-3)(2).py (13-16). All compounds were characterized by multi nuclear NMR, vibrational (IR, Raman) spectroscopy; and the molecular struct ures of 1, 3, 8, 10a ([(CF3)(3)C6H2](2)BN3/[(CF3)(3)C6H2](2)BOH) and 14 wer e established by single crystal X-ray crystallography. (C) 2001 Elsevier Sc ience B.V. All rights reserved.