These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Metal-induced B-H activation: addition of methyl acetylene carboxylates to Cp*Rh-, Cp*Ir-, (p-cymene)Ru-, and (p-cymene)Os half-sandwich complexes containing the chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand.
    Author: Herberhold M, Yan H, Milius W, Wrackmeyer B.
    Journal: Chemistry; 2000 Aug 18; 6(16):3026-32. PubMed ID: 10993263.
    Abstract:
    The reactions of the 16e half-sandwich complexes [Cp*M[S2C2(B10)H10)]] (1: M=Rh; 2: M = Ir) and [eta6-(4-isopropyltoluene)M[S2C2(B10H10)] (3: M=Ru; 4: M=Os) with both methyl acetylene monocarboxylate and dimethyl acetylene dicarboxylate were studied in order to obtain more evidence for B-H activation, ortho-metalation, and B(3,6)-substitution of the carborane cluster. In the case of rhodium, the reaction of 1 with methyl acetylene monocarboxylate led to new complexes after twofold insertion into one of the Rh-S bonds (7), and twofold insertion together with B-substitution at the carborane cage (8). In the case of iridium, the reactions of 2 with methyl acetylene monocarboxylate gave two geometrical isomers 10 and 11, in which the alkyne is inserted into one of the Ir-S bonds, followed by hydrogen transfer from the carborane via the metal to the former alkyne and formation of an Ir-B bond. Only one type each (12 and 13) of these isomers was obtained from the reactions of the ruthenium and osmium half-sandwich complexes 3 and 4. The 16e starting materials 1-4 reacted with dimethyl acetylene dicarboxylate at room temperature to give the complexes 14-17, respectively, which are formed by addition of the C=C bond to the metal center and insertion into one of the metal-sulfur bonds. The proposed structures in solution were deduced from NMR data (1H, 11B, 13C, 103Rh NMR), and X-ray structural analyses were carried out for the rhodium complexes 7 and 8.
    [Abstract] [Full Text] [Related] [New Search]