Dimerization of terminal alkynes catalyzed by chloro(η5-pentadienyl) bis(triphenylphosphine)ruthenium(II) and kinetics of phosphine substitution
作者:Matthew Daniels、Rein U. Kirss
DOI:10.1016/j.jorganchem.2006.12.031
日期:2007.3
is obtained for the reaction at 21 °C. The rate constant is essentially independent of the phosphine concentration. The activation parameters, ΔH† = 16.1 ± 0.4 kcal mol−1 and ΔS† = −16 ± 1 cal K−1 mol−1 differ from those reported for phosphine exchange in CpRu(PPh3)2Cl (2) and (η5-indenyl)Ru(PPh3)2Cl (3). The reaction of 1 with PMe2Ph is about 70 times faster than the reaction of 2 at 30 °C and some
PME的交换2 Ph代表PPH 3中(η 5 -戊二烯基)钌二(三苯基膦)氯化},(η 5 -C 5 H ^ 7)的Ru(PPH 3)2 Cl(上1)第一级的条件下迅速地进行在室温下为THF。对于在21℃下的反应,获得的假一级反应速率常数为17±2×10 -4 s -1。速率常数基本上与膦浓度无关。激活参数ΔH † = 16.1±0.4 kcal mol -1和ΔS † = -16±1 cal K -1 摩尔-1从所报道的在CPRU膦交换(PPH不同3)2 Cl(上2)和(η 5 -茚基)钌(PPH 3)2 Cl(上3)。的反应1用Pme 2 Ph是比的反应快约70倍2在30℃和比的反应快约40倍3在20℃下。(η 5 -C 5 H ^ 7)的Ru(PPH 3)2 Cl(上1)比钌更积极的(II)配合物2,3和TpRu(PPh 3)2 Cl(4)在末端炔烃催化二聚反应中与PhCCH
rhodium-(Z)-butatriene complexes 3. The butatrienes coordinated to Rh with the central double bond in an η2-fashion. (Z)-Butatrienes on 3 isomerized to (E)-form at 70 °C to afford (E)-butatriene complexes 4 with excellent E/Z ratios (E/Z = 97/3–99/1). The molecular structure of 4b (R = SiMe3, Ar = p-tolyl) was determined by X-ray diffraction analysis. Hydrosilation of 1 was catalyzed by rhodiumcomplexes to give
1,4-二取代丁三烯,(Z)-R-CH=C=C=CH-R (1, R = SiMe3, t-Bu),与 RhCl(PAr3)3 (Ar = Ph, p-tolyl ) 得到铑-(Z)-丁三烯配合物 3. 丁三烯以 η2 方式与中心双键配位到 Rh。3 上的 (Z)-丁三烯在 70 °C 下异构化为 (E)-形式,以提供具有优异 E/Z 比 (E/Z = 97/3–99/1) 的 (E)-丁三烯配合物 4。4b (R = SiMe3, Ar = p-tolyl) 的分子结构通过 X 射线衍射分析确定。1 的氢化硅烷由铑配合物催化得到丙二烯作为主要产物,伴随着 1,3-二烯作为次要产物,这是硅烷的 2,1-加成和 2,3-反加成的结果。
C–C coupling reactions in the coordination sphere of rhodium(<scp>i</scp>) and rhodium(<scp>iii</scp>): New routes for the di- and trimerization of terminal alkynes
作者:Martin Schäfer、Justin Wolf、Helmut Werner
DOI:10.1039/b415541f
日期:——
at room temperature reacts by C–C coupling to give trans-[RhClη2-(Z)-PhCCCHCHPh}(PiPr3)2] (Z)-21. The related compound trans-[RhCl(η2-HCCCHCH2)(PiPr3)2] 27, prepared from trans-[Rh(CCH)(CCH2)(PiPr3)2] 17 and HCl, rearranges to the vinylvinylidene isomer trans-[RhCl(CCHCHCH2)(PiPr3)2] 28. While stepwise reaction of 2 with CF3CO2H yields, via alkynyl(vinyl)rhodium(III) intermediates (Z)-29 and (E)-29