2003 Organo-silicon compounds

Organo-silicon compoundsS 0060 Synthesis, Structure, and Photochemistry of 2,3,5,6-Tetrasilyl-1,4-benzoquinones

and Related Compounds. — Halobenzoquinones (I) react with silyl or germyl chlo-rides (II) and magnesium to the dimetaloxybenzene derivatives (III), which yield the title compounds (IV) by oxidation. This method is applicable to the preparation of some disilyl- and digermylbenzoquinones, and 2-silylbenzoquinone. Tetrasilylated benzo-quinones and related compounds are studied as new fully silylated π-electron systems. Furthermore, dimethoxybenzene derivative (VII) serves as useful precursor of silylben-zoquinones, as exemplified with the preparation of (XI) and (XII). Photolysis of (IVa) leads to the isomerized ketene derivative (VI). X-ray analysis shows that the quinone ring of (IVa) is distorted into a chair form. — (TSUTSUI, S.; SAKAMOTO*, K.; EBATA, K.; KABUTO, C.; SAKURAI, H.; Bull. Chem. Soc. Jpn. 75 (2002) 12, 2571-2577; Photodyn. Res. Cent., Inst. Phys. Chem. Res., Aoba, Sendai 980, Japan; Eng.) — H. Hoennerscheid

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