Efficient photodecarboxylation of trifluoromethyl-substituted phenylacetic and mandelic acids.
A total of eight CF(3)-substituted phenylacetic and mandelic acids are shown to undergo efficient photodecarboxylation (PDC; Phi = 0.37-0.74) in basic aqueous solution to give the corresponding trifluoromethyltoluenes or trifluoromethylbenzyl alcohols. The products are consistent with the almost exclusive formation of benzylic carbanions that subsequently react with water, with minor amounts (< or = 5%) of radical-derived products detected. Quenching studies indicate that the reaction likely proceeds from the singlet excited state. This work demonstrates that the CF(3) group greatly facilitates the excited state ionic PDC of phenylacetic acids.
Burns
Misty-Dawn
MD
Department of Chemistry, Acadia University, Wolfville, NS, Canada.
Lukeman
Matthew
M
D001592:Benzyl Alcohols / Q000138:chemical synthesis / Q000737:chemistry; D003653:Decarboxylation; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D008333:Mandelic Acids / Q000737:chemistry*; D015394:Molecular Structure; D010648:Phenylacetates / Q000737:chemistry*; D010777:Photochemistry; D011789:Quantum Theory; D013237:Stereoisomerism; D014050:Toluene / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D014466:Ultraviolet Rays
D001592:Benzyl Alcohols; D006845:Hydrocarbons, Fluorinated; D008333:Mandelic Acids; D010648:Phenylacetates; D014050:Toluene; C025136:phenylacetic acid