名称:
Novel heterocycles from alkylamino-bis(trifluoromethyl) borane, (CF3)2BNR2, and isocyanides. Crystal and molecular structure of (NC)(CF3)2B · NHMe2,
摘要:
Dialkylamino-bis(trifluoromethyl)boranes, (CF3)(2)BNR(2)(1) [R(1) = Me (A), Et (B)] react at -20 degrees C with (t)BuNC to form the respective adducts ((t)BuNC)(CF3)(2)BNR(2)(1)[R(1) = Me (I), Et (II)]. At 20 degrees C these eliminate isobutylene to yield the amine boranes (NC)(CF3)(2)B . NHR(2)(1) [R(1) = Me (III), Et (IV)]. (PrNC)-Pr-1 combines with A in a 2:1 ratio to yield the four-membered heterocycle (CF3)(2)B-NMe(2)-C(=(NPr)-Pr-i)-C(=(NPr)-Pr-i) (V) and in a 2:2 ratio to form (CF3)(2)B-NMe(2)-B(CF3)(2)-NR=C-C(NMe(2))-NR [R=Pr-i (VI)]. Heterocycles corresponding to VI with R = (n)Bu (VII), Et (VIII) and Me (IX) were obtained by the respective reactions of (n)BuNC, EtNC and MeNC with A. The reaction of PhCH(2)NC with A leads to the formation of the heterobicyclo-octane (CF3)(2)B-NMe(2)-B(CF3)(2)-CH-C(=NMe(2))-N(CH(2)Ph)-CH(Ph)-N (X). The novel boron compounds have been characterized by multinuclear NMR, IR and mass spectra. The structures of III, VIII and X have been investigated by single-crystal X-ray diffraction.