Ryouichi Akaishi

First example of tetraalkyl substituted ditelluride dication salt from 1,5-ditelluracyclooctane

A new cyclic bis-telluride, 1,5-ditelluracyclooctane (1), has been synthesized. Two-electron oxidation of 1 with two equivalents of NOBF4 or NOPF6 afforded a novel ditelluride dication BF4- or PF6- salt 2 which was characterized by 125Te NMR spectroscopy, and the dication 2 behaves as an oxidizing agent.

Preparation and reactivity of dichalcogenide (S, Se) dication salts from medium-sized cyclic bis-sulfide and bis-selenides

Abstract The disulfide dication salt, 1,5-dithioniabicyclo[3.3.0]octane bis(trifluoromethanesulfonate) ( 3 ), was isolated from the reaction of 1,5-dithiacyclooctane 1-oxide with trifluoromethanesulfonic anhydride. Two-electron oxidation of 1,5-diselenacyclooctane with two equivalents of NOPF 6 or NOBF 4 gave the first diselenide dication salt, 1,5-diselenoniabicyclo-[3.3.0]octane bis(hexafluorophosphate) or bis(tetrafluoroborate ( 5 ). The disulfide and diselenide dication salts ( 3 and 5 ) act as an oxidant or as an electrophile depending on the added reagents.

1,5-Diselenacyclo-octane: synthesis and the first isolation of the diselenide PF6– salt [R2Se+–Se+R2]

A new cyclic bis-selenide, 1,5-diselenacyclo-octane (1) has been prepared; two-electron oxidation of (1) with two equivalents of NOPF6 gave a novel diselenide PF6– salt which acts as an oxidizing agent.

Chemical and electrochemical reduction of diselenide dication salt, 1,5-diselenoniabicyclo[3.3.0]Octane bis(hexafluorophosphate)

Abstract The reaction of the diselenide dication salt, 1,5-diselenoniabicyclo[3.3.0]octane bis(hexafluorophosphate) ( 1 ) with 1,5-diselenacyclooctane ( 2 ) gave the corresponding cation radical by single-electron transfer. The dication salt 1 was reduced upon treatment with fluorenyl-lithium, Na 2 S, NaBH 4 ; it did not deprotonate. The cyclic voltammetry of 1 shows the reversible reduction peak at remarkably low reduction potential.

Transannular sulfur-sulfur interaction in 3,7,9-trithiabicyclo[3.3.1]nonane as a new cyclic tris-sulfide: quest for the intrabridged dithia dication

Abstract A new cyclic tris-sulfide, 3,7,9-trithiabicyclo[3.3.1] nonane ( 1 ) has been synthesized. Transannular S-S interaction in 1 was found in the reactions of 1 and its sulfoxide with concd H 2 SO 4 and in electrochemical oxidation.

A new preparative method, characterization, and reactivity of disulphide dication salts of cyclic bis-sulphides: R2S–SR2·2CF3SO3–

The reaction of 1,5-dithiacyclo-octane 1-oxide with trifluoromethanesulphonic anhydride affords the corresponding disulphide dication as a stable crystalline salt which serves as an oxidizing agent in the oxidation of 1,2-diphenylhydrazine; the disulphide dication of 1,4-dithiane has also been isolated.

A novel redox reaction of the disulphide dication salt (R2S+–+SR2·2X–) with carbanions and alkoxides

The disulphide dication salt, 1,5-dithioniabicyclo[3.3.0]octane bis(trifluoromethanesulphonate)(1) was reduced upon treatment with carbanions or alkoxides; it did not deprotonate.