226922-34-5Relevant academic research and scientific papers
Transfer of ketyls from alkali metals to transition metals. Formation and diverse reactivities of D-block transition-metal ketyls
Hou, Zhaomin,Fujita, Akira,Koizumi, Take-aki,Yamazaki, Hiroshi,Wakatsuki, Yasuo
, p. 1979 - 1985 (1999)
This paper reports our studies on the preparation of d-block transition-metal ketyls via metathesis reactions of alkali-metal ketyls with transition-metal chlorides as well as via deprotonation of pinacols with a transition-metal base. The metathesis reaction of sodium fluorenone ketyl with (C5Me5)2ZrCl2 in THF gave the corresponding zirconium fluorenone ketyl complex (C5Me5)2Zr(OC13H8)Cl (1), which represents the first example of a structurally characterized d-block transition-metal ketyl complex. In the case of sodium benzophenone ketyl, further reaction between the ketyl radical and a C5Me5 ligand took place to give finally the zirconium bis(alkoxide) complex (η5-C5Me5)(η5:η 1-C5Me4CH2C(Ph) 2O)Zr(OCHPh2) (2). In contrast, the similar reaction of [(C5Me5)Ir(μ-Cl)Cl]2 with sodium fluorenone ketyl yielded the iridium carbonyl complex (C5Me5)Ir(CO)(C12H8) (5), as a result of decarbonylation of fluorenone. When [(C5Me5)Ir(μ-H)Cl]2 was used to react with sodium fluorenone or benzophenone ketyl, the dechlorination (reduction) product [(C5Me5)Ir(μ-H)]2 (8), together with fluorenone or benzophenone, formed selectively. The ketone-free 8 could be obtained in high yields by reaction of [(C5Me5)Ir(μ-H)Cl]2 with 2 equiv of K or Na in THF. The reaction of 1,2-bis(biphenyl-2,2′-diyl)ethane-1,2-diol (9) with the iridium imido complex (C5Me5)IrNtBu in THF gave a mixture of 5 (30%) and 8·2(fluorenone) (30%). However, when the reaction was carried out in benzene, the pinacolate complex (C5Me5)Ir(O2C26H16) (10) was formed as a major product (73%) together with a small amount of 5 (9%) and 8 (13%).
