REACTIVITY OF [TPRUCL(DIPPE)] TOWARD 1-ALKYNES - X-RAY CRYSTAL-STRUCTURES OF [TPRU=C(OME)CH2COOME(DIPPE)][BPH4] AND [TPRU(C-CC(PH)=CH2)(DIPPE)] (DIPPE=1,2-BIS(DIISOPROPYLPHOSPHINO)ETHANE, TP=HYDROTRIS(PYRAZOLYL)BORATE)

The complex [TpRuCl(dippe)] (Tp = hydrotris(pyrazolyl)borate) reacts w ith 1-alkynes in MeOH in the presence of NaBPh4 yielding vinylidene co mplexes [TpRu=C=CHR(dippe)]-[BPh4]. When R = COOMe, the vinylidene der ivative reacts further with MeOH furnishing the corresponding methoxy- carbene complex [TpRu=C(OMe)CH2COOMe(dippe)][BPh4]. The X-ray crystal structure of this compound was determined. The vinylidene complexes, a s well as the methoxy-carbene derivative, react with KOBut yielding ne utral alkynyls [TpRu(C drop=CR)(dippe)]. The reaction of [TpRuCl(dippe )] with propargyl alcohols HC drop CCRR'(OH) leads to different produc ts depending on the R groups. Thus, with HC drop CCMePh(OH), the allen ylidene complex [TpRu=C=C=CMePh(dippe)][BPh4] was obtained. This compo und is deprotonated by strong bases at the delta carbon, yielding the enynyl derivative [TpRu(C drop CC(Ph)=CH2)(dippe)], which was studied by X-ray diffraction. The reaction of [TpRuCl(dippe)] with HC drop CCM e2(OH) leads to a deep red binuclear vinylidene-carbene complex of com position [{TpRu(dippe)}(2) (mu-C10H12)][PF6](2), formally derived from the coupling of one: isoprenyl-vinylidene species, generated in situ, to an allenylidene moiety. This coupled product is readily deprotonat ed by weak bases furnishing the blue binuclear allenylidene/alkynyl-ca rbene complex [{TpRu(dippe)}(2)(mu-C10H11)](+), which was isolated as a [BPh4](-) salt. All compounds were characterized by microanalysis, I R, and NMR spectroscopy.