Photooxygenation of 5-Dialkylamino-4-pyrrolin-3-ones. Synthesis of Highly Functionalized Ureas, 2-Oxazolidinones, and 2-Oxazolinones

• Published in: Journal of organic chemistry Vol. 73; no. 17; pp. 6943 - 6945
• Main Authors: Erden, Ihsan, Özer, Galip, Hoarau, Christophe, Cao, Weiguo, Song, Jiangao, Gärtner, Christian, Baumgardt, Ingmar, Butenschön, Holger
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 05.09.2008; Amer Chemical Soc
• Subjects: Acetates - chemistry; Alkanes - chemistry; Alkynes - chemistry; Amidines - chemistry; Amines - chemistry; Catalysis; Chemistry; Chemistry, Organic; Cyclization; Exact sciences and technology; Heterocyclic compounds; Heterocyclic Compounds - chemistry; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Heterocyclic Compounds, 1-Ring; Hydrogenation; Methanol - chemistry; Models, Chemical; Organic chemistry; Oxazoles - chemical synthesis; Oxazolidinones - chemical synthesis; Oxygen - chemistry; Photochemistry; Physical Sciences; Preparations and properties; Pyrroles - chemistry; Science & Technology; Solvents - chemistry; Urea - chemical synthesis; C=N BOND; SINGLET OXYGEN; LACTONES; CLEAVAGE; DYE-SENSITIZED PHOTOOXYGENATION; 1,8-Diazabicyclo[5.4.0]undec-7-ene; Catalytic reaction; Condensation reaction; Nitrogen heterocycle; Dimethyl butynedioate; Singlet state; Oxygen heterocycle; Hydrogenation; Pyrrole derivatives; Amidine; Cycloaddition; Cyclization; Functionalization; Oxazolidinone derivative; Cleavage; Ureas; Pyrrolidone derivatives; Oxygenation; Chemical synthesis; Oxazole derivatives; Photooxidation; Oxygen nitrogen heterocycle; Methanol
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo801192z

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.