Reverse selectivity in m-CPBA oxidation of oligothiophenes to sulfones.
Oligothiophene sulfones of up to six rings can be conveniently prepared by the direct oxidation of butyl-substituted thiophene oligomers with m-CPBA in dichloromethane. Reverse selectivity of oxidized rings is observed relative to previously reported systems without beta-substitution. The selectivity in the trimer and hexamer is confirmed with single-crystal X-ray structure data. The sulfones possess red-shifted absorptions and increased electron affinities relative to the parent oligomers.
Pappenfus
Ted M
TM
Division of Science and Mathematics, University of Minnesota, Morris, Minnesota 56267, USA. pappe001@morris.umn.edu
Melby
Jacob H
JH
Hansen
Brent B
BB
Sumption
Devin M
DM
Hubers
Scott A
SA
Janzen
Daron E
DE
Ewbank
Paul C
PC
McGee
Kari A
KA
Burand
Michael W
MW
Mann
Kent R
KR
D002723:Chlorobenzoates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013450:Sulfones / Q000138:chemical synthesis* / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry*
D002723:Chlorobenzoates; D013450:Sulfones; D013876:Thiophenes; C000433:3-chloroperbenzoic acid