1,2,3-TRIBOROLANES FROM NORBORNENE DERIVATIVES, ALLYLBENZENE AND DEHALOGENATION PRODUCTS OF DICHLORO(DIISOPROPYL-AMINO)BORANE - 2,4,5-TRIS(DIISOPROPYLAMINO)-2,4,5-TRIBORABICYCLO[1.1.1]PENTANE - BICYCLUS OR CARBORANE

The new 1,2,3-tris(diisopropylamino)triborolanes 1, 2, 3 and 4 have been prepared by treatment of mixtures of 2-norbornene (A), 5-methylene-2-norbornene (B), 5-ethylidene-2-norbornene (C) and allylbenzene (D) with dichloro(diisopropylamino)borane with Na/K alloy in hexane. The corresponding species 5, derived from 2,5-norbornadiene (E), is relatively unstable and by a retro Diels-Alder reaction gives 2,3,4-tris(diisopropylamino)-1,5-dicarba-closo-pentaborane(5) (6). The compounds are characterized by chemical analyses, MS and NMR (H-1, B-11, C-13, N-15) and 1, 4 and 6 also by X-ray structure analyses.