10.1021/om0003887.s001 Hideo Nagashima Hideo Nagashima Akihiro Suzuki Akihiro Suzuki Takafumi Iura Takafumi Iura Kazuhiro Ryu Kazuhiro Ryu Kouki Matsubara Kouki Matsubara Stoichiometric and Catalytic Activation of Si−H Bonds by a Triruthenium Carbonyl Cluster, (μ<sub>3</sub>,η<sup>2</sup>:η<sup>3</sup>:η<sup>5</sup>-acenaphthylene)Ru<sub>3</sub>(CO)<sub>7</sub>:  Isolation of the Oxidative Adducts, Catalytic Hydrosilylation of Aldehydes, Ketones, and Acetals, and Catalytic Polymerization of Cyclic Ethers American Chemical Society 2000 Oxidative Adducts CO ligand cyclic ether trialkylsilanes results NMR studies THF representative example 4 O Mechanistic considerations Catalytic Polymerization Catalytic Activation catalysts 1 cyclic ethers silyl ethers Cyclic Ethers Treatment Triruthenium Carbonyl Cluster M n CH RhCl ketone oxidative addition stoichiometric amounts Catalytic Hydrosilylation acenaphthylene hydrosilylation Compound 1 catalyzes NMR spectroscopy HSiR 3 carbonyl compounds room temperature 2000-08-05 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Stoichiometric_and_Catalytic_Activation_of_Si_H_Bonds_by_a_Triruthenium_Carbonyl_Cluster_sub_3_sub_sup_2_sup_sup_3_sup_sup_5_sup_-acenaphthylene_Ru_sub_3_sub_CO_sub_7_sub_Isolation_of_the_Oxidative_Adducts_Catalytic_Hydrosilylation_of_Aldehydes_Ketones_an/3762990 Treatment of the ruthenium cluster (μ<sub>3</sub>,η<sup>2</sup>:η<sup>3</sup>:η<sup>5</sup>-acenaphthylene)Ru<sub>3</sub>(CO)<sub>7</sub> (<b>1</b>) with stoichiometric amounts of trialkylsilanes results in liberation of a CO ligand followed by oxidative addition of a Si−H bond. The trinuclear silyl complexes (μ<sub>3</sub>,η<sup>2</sup>:η<sup>3</sup>:η<sup>5</sup>-acenaphthylene)Ru<sub>3</sub>(H)(SiR<sub>3</sub>)(CO)<sub>6</sub> (<b>2</b>) were isolated in good yield. They were characterized by NMR spectroscopy and X-ray crystallography. Compound <b>1 </b>catalyzes the hydrosilylation of olefins, acetylenes, ketones, and aldehydes. In particular, the reactions of aldehydes and ketones proceed at room temperature to form the corresponding silyl ethers in good yield; the catalytic activities are superior to those with RhCl(PPh<sub>3</sub>)<sub>3</sub>. The RhCl(PPh<sub>3</sub>)<sub>3</sub>-catalyzed hydrosilylation of ketones with Me<sub>2</sub>(H)SiCH<sub>2</sub>CH<sub>2</sub>Si(H)Me<sub>2</sub> results in selective reaction of only one Si−H terminus, while similar reactions, when catalyzed by <b>1</b>, allow utilization of both Si−H groups. Significantly different regio- and stereoselectivities, compared with those obtained in reactions catalyzed by RhCl(PPh<sub>3</sub>)<sub>3</sub>, also were observed in the hydrosilylation of α,β-unsaturated carbonyl compounds and 4-<i>tert</i>-butylcyclohexanone, respectively. The reactions with acetals and cyclic ethers also take place under similar conditions. The reaction of trialkylsilanes with an excess of a cyclic ether resulted in ring-opening polymerization. Polymerization of THF was investigated as a representative example. Treatment of trialkylsilanes with an excess of THF (10−10<sup>2</sup> equiv with respect to silanes) in the presence of a catalytic amount of <b>1</b> resulted in production of polytetrahydrofuran with <i>M</i><sub>n</sub> = 1000−200 000 and <i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> = 1.3−2.0. Changing the ratio of THF to HSiR<sub>3</sub> can control the molecular weight. NMR studies suggested that the structure of the polymer is R<sub>3</sub>SiO−[(CH<sub>2</sub>)<sub>4</sub>O]<i><sub>n</sub></i>−CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub>. Mechanistic considerations based on differences in the catalytic activities between the catalysts <b>1</b> and <b>2</b> are discussed.