| Research Abstract |
1. Experimental Evidences for 1,2-and 1,3-Migration Reactions on Silyl-and Aryl(silylene) Complexes We developed thermal as well as photochemical synthetic methods for a donor-free silyl(silylene)iron complex Cp^*Fe(CO)(=SiMes_2)SiMe_3 (1), and determined its X-ray crystal structure. Thermal reaction of 1 at 80℃ in the presence of CO gave a disilanyl complex Cp^*Fe(CO)_2SiMeMesSiMe_2Mes (2a) and its isomer 2b. Photolysis of either 2a or 2b reproduced 1 quantitatively. These results provide the most straightforward evidences for extremely facile 1,2- and 1,3-group migration reactions in silyl(silylene) complexes. Similarly, we found that, on an (arylsilyDtungsten complex, an aryl group on the silyl ligand underwent 1,2-migration to a coordinatively unsaturated metal center in the presence of base to give a base-stabilized silylene complex.
2. Synthesis, Structures, and Reactivity of Hydrido(hydrosilylene)tungsten Complexes : Photoreaction of Cp^*(CO)_3WMe with sterically hindered trihydr
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osilane H_3SiC(SiMe_3)_3 in a sealed tube afforded a mixture of hydridoOiydrosilylene) complex and a silyl complex. The hydrosilylene complex was isolated as a single product by irradiation with periodic removal of CO. Crystal structure analyses and NMR spectroscopy of the η^5C_5Me_4Et derivative of the hydrosilylene complex revealed the existence of strong hydrido-silylene interligand interaction, which was also supported by DFT calculation. The hydrido(hydrosilylene) complex reacted smoothly with various polar molecules such as ketones, enones, nitriles, oxiranes, etc. to give new types of addition products.
3. Reactions of Phosphasilaferracyclopropane with Various Polar Molecules : Photoreaction of carbonyl(phosphinosilyl)iron complex at low temperature afforded phosphasilaferracyclopropane via CO dissociation. Phosphasilaferracyclopropane reacted with several organic molecules having polarized unsaturated bonds such as 4-(dimethylamino)pyridine, benzaldehyde, ketones, and enones to give insertion products with a five-membered chelate ring. It also reacted with various molecules having a polarized single bond E-H (E = O, S, N, and P) instantaneously at room temperature to afford silyl(hydrophosphine)iron complexes. Less
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