C−O Bond Fragmentation of 4-Picolyl- and N-Methyl-4-picolinium Esters Triggered by Photochemical Electron Transfer
摘要:
Photochemical reduction of several 4-picolyl- and N-methyl-4-picolinium esters was examined using product analysis, laser flash photolysis, and fluorescence quenching. It is demonstrated that the radical (anions) formed in these reactions readily fragment to yield a carboxylic acid and a 4-pyridylmethyl radical intermediate. The high chemical and quantum yields observed for these photoreactions suggests that these esters can be used as photolabile protecting groups.
C−O Bond Fragmentation of 4-Picolyl- and N-Methyl-4-picolinium Esters Triggered by Photochemical Electron Transfer
摘要:
Photochemical reduction of several 4-picolyl- and N-methyl-4-picolinium esters was examined using product analysis, laser flash photolysis, and fluorescence quenching. It is demonstrated that the radical (anions) formed in these reactions readily fragment to yield a carboxylic acid and a 4-pyridylmethyl radical intermediate. The high chemical and quantum yields observed for these photoreactions suggests that these esters can be used as photolabile protecting groups.
Photolytic Release of Carboxylic Acids Using Linked Donor−Acceptor Molecules: Direct versus Mediated Photoinduced Electron Transfer to <i>N</i>-Alkyl-4-picolinium Esters
作者:Chitra Sundararajan、Daniel E. Falvey
DOI:10.1021/ol050744n
日期:2005.6.1
[reaction: see text] Efficient photorelease (Phi = 0.7) of carboxylic acids is achieved with a covalently linked mediator (benzophenone) protecting group (N-alkyl-4-picolinium ester) molecule. The mechanism involves initial photoreduction of the mediator, followed by rapid electrontransfer to the protecting group.
C−O Bond Fragmentation of 4-Picolyl- and <i>N</i>-Methyl-4-picolinium Esters Triggered by Photochemical Electron Transfer
作者:Chitra Sundararajan、Daniel E. Falvey
DOI:10.1021/jo049501j
日期:2004.8.1
Photochemical reduction of several 4-picolyl- and N-methyl-4-picolinium esters was examined using product analysis, laser flash photolysis, and fluorescence quenching. It is demonstrated that the radical (anions) formed in these reactions readily fragment to yield a carboxylic acid and a 4-pyridylmethyl radical intermediate. The high chemical and quantum yields observed for these photoreactions suggests that these esters can be used as photolabile protecting groups.