A New Oxidative Se-Dealkylation in Seleno-Pummerer Reaction of 1,8-Bis(methylseleno)naphthalene and Naphtho[1,8-b,c]-1,5-diselenocin Induced by Peri-Selenium Participation

Abstract

A new type of oxidative Se-dealkylation reaction was found in either the reaction of 1,8-bis(methylseleno)naphthalene and naphtho[1,8-b,c]-1,5-diselenocin with benzoyl peroxide or the reaction of their Se-oxides with carboxylic acid anhydrides.

1,2-Dications in Organic Main Group Systems

“…In the case of most labile compounds, substitution at the carbon atom of diselenonium and ditelluronium dications is also a possible pathway. For example, formation of diselenide 159 from selenoxide 157 was explained by demethylation of intermediate dication 158 with trifluoroacetate anion …”

“…For example, formation of diselenide 159 from selenoxide 157 was explained by demethylation of intermediate dication 158 with trifluoroacetate anion. 197 Dealkylation of salt 160, which is stable up to -20 °C, leads to formation of a nitrilium salt 161. The latter is transformed to amide 162 upon hydrolysis.…”

Successive Change in Conformation Caused by p-Y Groups in 1-(MeSe)-8-(p-YC6H4Se)C10H6: Role of Linear Se···Se−C Three-Center−Four-Electron versus n(Se)···n(Se) Two-Center−Four-Electron Nonbonded Interactions

“…The lone pair−lone pair interaction is one of the important factors to determine the structure and the reactivity of organic compounds containing heteroatoms bearing lone pairs such as organic chalcogen compounds. Such two-center−four electron (2c−4e) interaction is demonstrated to play an important role in the nuclear spin−spin couplings between selenium−selenium , and selenium−fluorine atoms, as well as those between fluorine−fluorine and fluorine−nitrogen atoms. Naphthalene 1,8-positions are expected to serve as a good system to study the nonbonded interactions between heteroatoms and/or groups containing 2c−4e. ,,, …”

“…Such two-center−four electron (2c−4e) interaction is demonstrated to play an important role in the nuclear spin−spin couplings between selenium−selenium , and selenium−fluorine atoms, as well as those between fluorine−fluorine and fluorine−nitrogen atoms. Naphthalene 1,8-positions are expected to serve as a good system to study the nonbonded interactions between heteroatoms and/or groups containing 2c−4e. ,,, …”

Novel Thiofomylation of Primary and Secondary Amines Using N-Aryl-1,2,3,4,5,7-Pentathiazocanes

“…1-6 A dichloromethane solution of 2 was then treated with bromine-elemental sulfur or disulfur dichloride (S 2 Cl 2 ) at −78 • C, and in both cases, N-aryl-1,2,3,4,5,7-pentathiazocanes 1a-d were efficiently obtained through oxidative ring contraction of 1,5,3,7-dichalcogenadiazocines as shown in Scheme 2. 7,8 Conversion of 2 into 1 was assumed to proceed through a mechanism involving in situ formation of 1,5,3,7-dithiadiazabicyclo[3.3.0]octane-type mesocyclic dications 3 [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] followed by ring contraction and sulfur insertion. [27][28][29][30] Scheme 2 Preparation of N-aryl-1,2,3,4,5,7-pentathiazocanes 1.…”