A mechanistic investigation of anti-elimination in (Z)-1,2-bis(arylseleno)-1-alkenes and their sulfur analogs.
The oxidation of (Z)-1,2-bis(arylseleno)-1-alkenes is known to afford alkynyl selenoxides via a unique selenoxide anti-elimination mechanism; however, to date, there have been no mechanistic studies of this reaction. During our studies of this transformation, monoselenoxides 6 and 7 were unexpectedly isolated as stable reaction intermediates. In addition, (77)Se NMR studies of the reaction mixture revealed the presence of an intramolecular Se···O interaction and the formation of alkynyl selenoxides. Meanwhile, even at higher temperatures, the reaction of a (Z)-1,2-bis(arylsulfinyl)-1-alkene, the sulfur analog of (Z)-1,2-bis(arylseleninyl)-1-alkenes, did not proceed via sulfoxide elimination but proceeded via isomerization and disproportionation. Therefore, the intramolecular Se···O interaction can be concluded to play a pivotal role in the anti-elimination reaction.
School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, 11-68 Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179, Japan. nishide@mukogawa-u.ac.jp.
Asami
A
Tarao
Yukako
Y
Tabuchi
Eri
E
Sugimoto
Miki
M
Ikeda
Hitomi
H
Uchimoto
Kenji
K
Arimitsu
Hiroyuki
H
Kimura
Ikuo
I
Kawasaki
Masatoshi
M
Kawahata
Kentaro
K
Yamaguchi
Kiyoharu
K
Nishide
D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D007536:Isomerism; D008958:Models, Molecular; D016566:Organoselenium Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013457:Sulfur Compounds / Q000737:chemistry*
D000475:Alkenes; D016566:Organoselenium Compounds; D010087:Oxides; D013457:Sulfur Compounds