Seiji Ebine

A specific change of the electronic and 1C NMR spectra and redox potentials in 1,n-dithia[n]ferrocenophanes. A novel interaction between the sulphur atom and the ferrocene nucleus

Abstract Of the 1, n -dithia[ n ]ferrocenophanes prepared from disodium 1,1′-ferrocenedithiolate and polymethylene dibromides, the ferrocenophane with n = 7 showed the largest shift in the electronic and 13 C NMR spectra and the largest decrease of the redox potential. This can be interpreted by a new type of stereoelectronic interaction between the sulfur atom and the ferrocene nucleus.

Syntheses of ferrocenophanes containing aromatic or heteroaromatic rings in the bridging chain

Abstract 1,10-Dithia[2]- o -cyclo-, 1,10-dithia[2]- m -cyclo-, 1,10-dithia[2](2,6)pyridino-, and 1,9-dithia[2](2,5)furano-[2](1,1′)ferrocenophanes were synthesized. The structural features are discussed on the basis of spectral data and redox potentials.

Preparation and some properties of polyoxathiaferrocenophanes

Abstract Some sulfur analogs of a crown ether-like compound containing ferrocene as a ring member were prepared. Their complexing ability was poor with alkali metal cations but good with a silver cation.

[2.2](2,6)Biphenylenophane and [2](2,6)Biphenyleno[2](2,6)naphthalenophane

Biphenylen (Ia) wird in der angegebenen Weise in Bis-brommethyl- (le) und Bismercaptomethyl-biphenylen (If) ubergefuhrt.

Dichlorocarbene addition to 1,2-dimethoxybiphenylene. A chemical evidence for bond fixation in biphenylene nucleus

1,2-Dimethoxy-biphenylen (I) reagiert mit dem aus Chloroform und Alkali erhaltenen Dichlorcarben uber diskutierte Zwischenstufen mit einer anellierten 1,1-Dichlorcyclopropanstruktur zu den Reaktionsprodukten (III)-(IX).

(2.2)(2,6)BIPHENYLENOPHANE AND (2)(2,6)BIPHENYLENO(2)(2,6)NAPHTHALENOPHANE

Biphenylen (Ia) wird in der angegebenen Weise in Bis-brommethyl- (le) und Bismercaptomethyl-biphenylen (If) ubergefuhrt.

Synthesis and properties of cyclohepta[fg]naphth[2,3-a]acenaphthylene-5,12-dione (naphth[2,3-h]acepleiadylene-5,12-dione)

Naphth [2,3-h]acepleiadylene-5,12-dione (4) has been synthesized by the cycloaddition of acepleiadylene-5,8-dione (2) and o-dibromoquinodimethane generated in situ from 1,2-bis(dibromomethyl)benzene and sodium iodide. On the basis of their reduction potentials, determined by cyclic voltammetry, compound (4) and benz[h]acepleiadylene-5,10-dione (3) were shown to be [22]- and [18]-annulenediones, respectively. An unsuccessful attempt to synthesize naphth[2,3-h]acepleiadylene (7) is also described.

o-Pleiadienequinones. Part 2. Nucleophilic substitution reaction of o-pleiadienequinone with alcohols

In the course of the synthesis of the title compound (5) by the hydrolysis of the dichloro ketone (2) the acetoxy chloro ketone (6) was formed and accounted for in terms of the unusual bridgehead cation (3b). The nucleophilic substitution reaction of the compound (5) with various alcohols afforded alkoxy quinones (8) and/or acetals (7). The mechanism of the formation is discussed. The full characterization of 1-, 3-, and 6-methoxy quinones (8a1), (8a2), and (8a3) by spectroscopic and electrochemical methods is described. An attempt to effect the de-O-methylation of the methoxy quinones (8a), by the action of trimethylsilyl iodide, failed; dihydro quinones (15a), (15b), and (15c) resulted. The oxidative rearrangement of compound (5) to γ-lactone (17) in the reaction with iron(III) sulphate is described.

Synthesis and properties of acepleiadylene-5,6-dione and acepleiadylene-5,8-dione

Acepleiadylene-5,8-dione (1) and acepleiadylene-5,6-dione (2) have been synthesized by the stepwise oxidation of 6,7-dihydrocyclohept[fg]acenaphthene-5,8-dione (4) and 7,8-dihydrocyclohept[fg]acenaphthene-5,6-dione (21) derived from compound (4), respectively. The reduction potentials of compounds (1) and (2) were determined by cyclic voltammetry which showed that E1=–0.50 V and E2=–0.84 V for the former, and E1=E2=–0.29 V for the latter. Spectral and electrochemical data suggest that both diones (1) and (2) are [14]annulenediones with a vinyl cross-link. 5,8- and 5,6-Dihydroxyacepleiadylene, (9′) and (22′), exist in their keto-forms, 6,7-dihydrocyclohept[fg]acenaphthylene-5,8-dione (9) and 7,8-dihydrocyclohept[fg]acenaphthylene-5,6-dione (22), respectively.

Synthesis and properties of cyclohepta[de]naphthalene-7,8-dione, o-pleiadienequinone

Cyclohepta[de]naphthalene-7,8-dione, o-pleiadienequinone (2), was synthesized by hydrolysis of the acenaphthylene–dichloroketene adduct (5); chloro(hydroxy)ketone (6) was the precursor. Compound (2) afforded the triacetate (16) by a Thiele–Winter-type reaction and a phenalene compound (19) by alkaline hydrolysis. Spectral data suggest that the dione (2) has contributions from such canonical forms as 2,3-(2a) and/or 4,5-benzotropolonate (2b) structures. The polarographic E½ value of the dione (2) is –0.23 V at pH 5.28 which is between that of 1,2-naphthoquinone and anthraquinone.