Photooxygenation of 5-dialkylamino-4-pyrrolin-3-ones. Synthesis of highly functionalized ureas, 2-oxazolidinones, and 2-oxazolinones.
5-Dialkylamino-4-pyrrolin-3-ones, available from cyclocondensation of amidines with dimethyl acetylenedicarboxylate (DMAD), undergo rapid singlet oxygenation to give highly functionalized ureas by way of a 1,2-dioxetane cleavage of the initially formed [2 + 2] cycloadducts. These latter compounds undergo cyclization to 2-oxazolidinones in MeOH. Catalytic hydrogenation of the ureas in EtOAc gives 2-oxazolinones. The DBU-DMAD adduct undergoes photooxygenation by an entirely different pathway to give a large ring heterocycle.
Erden
Ihsan
I
Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132, USA. ierden@sfsu.edu
Ozer
Galip
G
Hoarau
Christophe
C
Cao
Weiguo
W
Song
Jiangao
J
Gärtner
Christian
C
Baumgardt
Ingmar
I
Butenschön
Holger
H
D000085:Acetates / Q000737:chemistry; D000473:Alkanes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry; D000578:Amidines / Q000737:chemistry; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000737:chemistry; D006573:Heterocyclic Compounds, 1-Ring; D006865:Hydrogenation; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D010080:Oxazoles / Q000138:chemical synthesis*; D023303:Oxazolidinones / Q000138:chemical synthesis; D010100:Oxygen / Q000737:chemistry*; D010777:Photochemistry; D011758:Pyrroles / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014508:Urea / Q000138:chemical synthesis*
D000085:Acetates; D000473:Alkanes; D000480:Alkynes; D000578:Amidines; D000588:Amines; D006571:Heterocyclic Compounds; D006573:Heterocyclic Compounds, 1-Ring; D010080:Oxazoles; D023303:Oxazolidinones; D011758:Pyrroles; D012997:Solvents; C079142:1,2-dioxetane; C007650:ethyl acetate; C022918:acetylenedicarboxylic acid dimethyl ester; D014508:Urea; D010100:Oxygen; D000432:Methanol