Synthesis of profluorescent isoindoline nitroxides via palladium-catalysed Heck alkenylation.
The synthesis of a new structural class of isoindoline nitroxides (aminoxyls), accessible via the palladium-catalysed Heck reaction, is presented. Reaction of the aryl bromoamine, 5-bromo-1,1,3,3-tetramethylisoindoline (4) or dibromoamine, 5,6-dibromo-1,1,3,3-tetramethylisoindoline (5) or the analogous bromonitroxides 6 and 7 with methyl acrylate gives the acrylate substituted tetramethylisoindoline amines 8 and 10 and nitroxides 12 and 14. Similarly, the reaction of the aryl bromides and dibromides 4-7 with methyl 4-vinylbenzoate gives the carboxystyryl substituted tetramethylisoindoline amines 9 and 11 and the analogous nitroxides 13 and 15. The carboxystyryl tetramethylisoindoline nitroxides demonstrate strongly suppressed fluorescence, which is revealed upon removal of the free radical by reduction or radical coupling.
School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Q4001 Australia.
Daniel J
DJ
Keddie
Therese E
TE
Johnson
Dennis P
DP
Arnold
Steven E
SE
Bottle
D000475:Alkenes / Q000737:chemistry*; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D005453:Fluorescence; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000138:chemical synthesis / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013267:Stilbenes / Q000737:chemistry*
D000475:Alkenes; D000975:Antioxidants; D007211:Indoles; D009589:Nitrogen Oxides; D013267:Stilbenes; D010165:Palladium; C039900:nitroxyl