Study on the selectivity in the electrophilic monofluorination of 2,3-allenoates with Selectfluor: an efficient synthesis of 4-fluoro-2(5H)-furanones and 3-fluoro-4-oxo-2(E)-alkenoates.
Different from the reaction of 2,3-allenoic acids with Selectfluor, 4-fluoro-2(5H)-furanones and (E)-3-fluoro-4-oxo-2-alkenoates were highly selectively generated from 2,4-disubstituted 2,3-allenoates with Selectfluor under different conditions in moderate yields. The reaction of 2,4,4-trisubstituted 2,3-allenoates afforded the corresponding 4-fluoro-2(5H)-furanones highly selectively with up to 95% yield under different conditions. The scope of the substrates has been carefully explored. Due to the more readily availability of 2,3-allenoates as compared to 2,3-allenoic acids, new 4-fluoro-2(5H)-furanones were prepared. Based on the isolation and characterization of the minor fluorohydroxylation product E-5m, a mechanism has been proposed.
Lü
Bo
B
Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China.
Fu
Chunling
C
Ma
Shengming
S
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D003979:Diazonium Compounds / Q000737:chemistry*; D015394:Molecular Structure; D010654:Phenylbutyrates / Q000138:chemical synthesis* / Q000737:chemistry
D003979:Diazonium Compounds; D010654:Phenylbutyrates; C408750:selectfluor; D015107:4-Butyrolactone