Ma, Chicheng published the artcilePhotochemical Cleavage and Release of Para-Substituted Phenols from ¦Á-Keto Amides, Safety of 2-(4-(Trifluoromethyl)phenoxy)acetic acid, the publication is Journal of Organic Chemistry (2006), 71(11), 4206-4215, database is CAplus and MEDLINE.
In aqueous media ¦Á-keto amides 4-YC6H4OCH2COCON(R)CH(R’)CH3 (5a, R = Et, R’ = H; 5b, R = iPr, R’ = Me) with para-substituted phenolic substituents (Y = CN, CF3, H) undergo photocleavage and release of 4-YC6H4OH with formation of 5-methyleneoxazolidin-4-ones 7a,b. For both 5a,b quantum yields range from 0.2 to 0.3. The proposed mechanism involves transfer of hydrogen from an N-alkyl group to the keto oxygen to produce zwitterionic intermediates 8a–c that eliminate the para-substituted phenolate leaving groups. The resultant iminium ions H2C:C(OH)CON+(R):C(R’)CH3?9a,b cyclize intramolecularly to give 7a,b. The quantum yields for photoelimination decrease in CH3CN, CH2Cl2, or C6H6 due to competing cyclization of 8a,b to give oxazolidin-4-one products which retain the leaving group 4-YC6H4O– (Y = H, CN). A greater tendency to undergo cyclization in nonaqueous media is observed for the N,N-di-Et amides 5a than the N,N-diisopropyl amides 5b. With para electron releasing groups Y = CH3 and OCH3 quantum yields for photoelimination significantly decrease and 1,3-photorearrangement of the phenolic group is observed The 1,3-rearrangement involves excited state ArO-C bond homolysis to give para-substituted phenoxyl radicals, which can be observed directly in laser flash photolysis experiments
Journal of Organic Chemistry published new progress about 163839-73-4. 163839-73-4 belongs to catalysis-chemistry, auxiliary class Trifluoromethyl,Fluoride,Carboxylic acid,Benzene,Ether, name is 2-(4-(Trifluoromethyl)phenoxy)acetic acid, and the molecular formula is C9H7F3O3, Safety of 2-(4-(Trifluoromethyl)phenoxy)acetic acid.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia