Chantler Victoria L, Chatwin Sarah L, Jazzar Rodolphe F R, Mahon Mary F, Saker Olly, Whittlesey Michael K
Department of Chemistry, University of Bath, Claverton Down, Bath, UK BA2 7AY.
Dalton Trans. 2008 May 21(19):2603-14. doi: 10.1039/b719373d. Epub 2008 Mar 26.
Thermolysis of [Ru(AsPh3)3(CO)H2] with the N-aryl heterocyclic carbenes (NHCs) IMes (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), IPr (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) or the adduct SIPr.(C6F5)H (SIPr=1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene), followed by addition of CH2Cl2, affords the coordinatively unsaturated ruthenium hydride chloride complexes [Ru(NHC)2(CO)HCl] (NHC=IMes , IPr , SIPr ). These react with CO at room temperature to yield the corresponding 18-electron dicarbonyl complexes . Reduction of and [Ru(IMes)(PPh3)(CO)HCl] () with NaBH4 yields the isolable borohydride complexes [Ru(NHC)(L)(CO)H(eta2-BH4)] (, L=NHC, PPh3). Both the bis-IMes complex and the IMes-PPh3 species react with CO at low temperature to give the eta1-borohydride species [Ru(IMes)(L)(CO)2H(eta1-BH4)] (L=IMes , PPh3), which can be spectroscopically characterised. Upon warming to room temperature, further reaction with CO takes place to afford initially [Ru(IMes)(L)(CO)2H2] (L=IMes, L=PPh3) and, ultimately, [Ru(IMes)(L)(CO)3] (L=IMes , L=PPh3). Both and lose BH3 on addition of PMe2Ph to give [Ru(IMes)(L)(L')(CO)H2](L=L'=PMe2Ph; L=PPh3, L'=PMe2Ph). Compounds and have been tested as catalysts for the hydrogenation of aromatic ketones in the presence of (i)PrOH and H2. For the reduction of acetophenone, catalytic activity varies with the NHC present, decreasing in the order IPr>IMes>>SIMes.
将[Ru(AsPh3)3(CO)H2]与N-芳基杂环卡宾（NHCs）1,3-双（2,4,6-三甲基苯基）咪唑-2-亚基（IMes）、1,3-双（2,6-二异丙基苯基）咪唑-2-亚基（IPr）或加合物SIPr·(C6F5)H（SIPr = 1,3-双（2,6-二异丙基苯基）-4,5-二氢咪唑-2-亚基）进行热解，然后加入二氯甲烷，得到配位不饱和的氢化钌氯化物配合物[Ru(NHC)2(CO)HCl]（NHC = IMes、IPr、SIPr）。这些配合物在室温下与CO反应生成相应的18电子二羰基配合物。用硼氢化钠还原[Ru(IMes)(PPh3)(CO)HCl]和（此处原文缺失具体化学式）得到可分离的硼氢化物配合物[Ru(NHC)(L)(CO)H(η2-BH4)]（此处原文缺失具体化学式），L = NHC、PPh3。双IMes配合物和IMes - PPh3物种在低温下与CO反应生成η1-硼氢化物物种[Ru(IMes)(L)(CO)2H(η1-BH4)]（L = IMes、PPh3），其可通过光谱表征。升温至室温后，与CO进一步反应，最初生成[Ru(IMes)(L)(CO)2H2]（L = IMes，L = PPh3），最终生成[Ru(IMes)(L)(CO)3]（L = IMes、L = PPh3）。加入二甲基苯基膦后，（此处原文缺失具体化学式）和（此处原文缺失具体化学式）均失去BH3，生成[Ru(IMes)(L)(L')(CO)H2]（L = L' = 二甲基苯基膦；L = PPh3，L' = 二甲基苯基膦）。已测试（此处原文缺失具体化学式）和（此处原文缺失具体化学式）在异丙醇和H2存在下作为芳香酮氢化催化剂的性能。对于苯乙酮的还原，催化活性随存在的NHC而异，活性顺序为IPr > IMes >> SIMes。
