| Autor: |
van 4;der 4;Vlugt, Jarl 4;Ivar, Ackerstaff, Jens, Dijkstra, Tessa 4;W., Mills, Allison 4;M., Kooijman, Huub, Spek, Anthony 4;L., Meetsma, Auke, Abbenhuis, Hendrikus 4;C. 4;L., Vogt, Dieter |
| Zdroj: |
Advanced Synthesis & Catalysis; March 2004, Vol. 346 Issue: 4 p399-412, 14p |
| Abstrakt: |
Silsesquioxanes are employed as ligand backbones for the synthesis of novel phosphite compounds with 3,3′-5,5′-tetrakis(tert-butyl)-2,2′-dioxa-1,1′-biphenyl substituents. Both mono- and bidentate phosphites are prepared in good yields. Two types of silsesquioxanes are employed as starting materials. The monophosphinite 1 and the monophosphite 2 are prepared from the thallium silsesquioxide derived from a completely condensed silsesquioxane framework (c-C5H9)7Si7O12SiOTl. The diphosphite 3 is synthesized starting with the incompletely condensed monosilylated disilanol (c-C5H9)7Si7O9(OSiMePh2)(OH)2. For monophosphite 2, the corresponding trans-[PtCl2(2)] complex 4 is characterized by NMR spectroscopy as well as by X-ray crystallography, as the first example of a completely condensed oxo-functionalized silsesquioxane framework. The coordination of the bidentate ligand 3 towards Pd, Mo and Rh is studied, both by NMR spectroscopy as well as by X-ray crystallography. Various modes of coordination are shown to be possible. The molecular structures for the complexes trans-[PdCl2(3)] (5), cis-[Mo(CO)4(3)] (6) and the dinuclear complex [{Rh(μ-Cl)(CO)}2(κ2-3)] (7) have been determined. In the rhodium-catalyzed hydroformylation of 1-octene high activities, with turnover frequencies of up to 6800 4;h−1, are obtained with these new nanosized phosphorus ligands. |
| Databáze: |
Supplemental Index |
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