Alkyl− and Aryl−Oxygen Bond Activation in Solution by Rhodium(I), Palladium(II), and Nickel(II). Transition-Metal-Based Selectivity
| Autor: | and Linda J. W. Shimon, Shyh-Yeon Liou, David Milstein, Yehoshoa Ben-David, Milko E. van der Boom |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Journal of the American Chemical Society. 120:6531-6541 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Reaction of [RhCl(C8H14)2]2 (C8H14 = cyclooctene) with 2 equiv of the aryl methyl ether phosphine 1 in C6D6 results in an unprecedented metal insertion into the strong sp2−sp3 aryl−O bond. This remarkable reaction proceeds even at room temperature and occurs directly, with no intermediacy of C−H activation or insertion into the adjacent weaker ArO−CH3 bond. Two new phenoxy complexes (8 and 9), which are analogous to the product of insertion into the ArO−CH3 bond (had it taken place) were prepared and shown not to be intermediates in the Ar−OCH3 bond cleavage process. Thus, aryl−O bond activation by the nucleophilic Rh(I) is kinetically preferred over activation of the alkyl−O bond. The phenoxy Rh(I)−η1-N2 complex (8) is in equilibrium with the crystallographically characterized Rh(I)−μ-N2−Rh(I) dimer (12). Reaction of [RhCl(C8H14)2]2 with 2 equiv of the aryl methyl ether phosphine 2, PPh3, and excess HSiR3 (R = OCH2CH3, CH2CH3) results also in selective metal insertion into the aryl−O bond and formation o... |
| Databáze: | OpenAIRE |
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