BORON NITROGEN-COMPOUNDS .124. PYRAZOLE DERIVATIVES OF 9-BORABICYCLO[3.3.1]NONANE

9-(Dimethylamino)-9-borabicyclo[3.3.1]nonane, (C8H14)BN(CH3)2, reacts with 1 molar equiv of pyrazole (=Hpz) to form the complex (C8H14)B(pzHCH3)2NH and with additional Hpz to yield (C8H14)B(pz)•Hpz. The latter complex is also obtained by the reaction of 9-borabicyclo[3.3.1]nonane dimer, [(C8H14)BH]2 (=9-BBN), with Hpz. The adduct can be deprotonated to form [(C8H14)B(pz)2]−, which reacts with PdCl2 to yield Pd[(μ-pz)2B(C8H14)]2. This same Pd complex is obtained when (C8H14)B-(pz)•(CH3)2NH is reacted with NaH and then with [ClPd(π-CH2CHCH2)]2 in boiling benzene, whereas at room temperature the latter reaction yields the complex [(pz)Pd(π-CH2CHCH2)]2. Reaction of [(C8H14)B(pz)2]− with [ClPd(π-CH2CHCH2)]2 yields the complex (C8H14)B(μ-pz)2Pd(π-CH2CHCH2). The pyrazabole (C8H14)B(μ-pz)2B(C8H14) is obtained by the reaction of (C8H14)B(pz)•Hpz with 9-BBN, the direct interaction of 9-BBN with Hpz, or the thermal decomposition of (C8H14)B(pz)• (CH3)2NH in molten Hpz. A relative of this pyrazabole, i.e., (C8H14)B(μ-pz)(μ-NHCH3)B(C8H14), is obtained by the reaction of (C8H14)B(pz)•CH3NH2 with 9-BBN. © 1990, American Chemical Society. All rights reserved.