Temperature Dependent Photochemical Cleavage of
2,5-Dimethylphenacyl Esters

J 2003

Temperature Dependent Photochemical Cleavage of 2,5-Dimethylphenacyl Esters

LITERÁK, Jaromír, Stanislav RELICH, Petr KULHÁNEK and Petr KLÁN

Basic information

Original name

Temperature Dependent Photochemical Cleavage of 2,5-Dimethylphenacyl Esters

Authors

LITERÁK, Jaromír (203 Czech Republic), Stanislav RELICH (203 Czech Republic), Petr KULHÁNEK (203 Czech Republic) and Petr KLÁN (203 Czech Republic, guarantor)

Edition

Molecular Diversity, Basel, Switzerland, Kluwer, 2003, 1381-1991

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10401 Organic chemistry

Country of publisher

Switzerland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 4.444 in 2001

RIV identification code

RIV/00216224:14310/03:00008279

Organization unit

Faculty of Science

UT WoS

000207200600021

Keywords in English

photochemistry; microwave; protecting groups

Abstract

V originále

The study of the temperature-sensitive photochemical release of a carboxylic acid from 2,5-dimethylphenacyl ester is reported. Quantum yields of the benzoate ester degradation in benzene increased from 0.22 at room temperature to 0.28 at 50 oC whereas a more significant increase (nearly by a factor of 3) was observed in methanol and ethanol, reaching a high reaction efficiency (0.25) typically found in non-polar solvents. The reaction proceeds predominantly via the triplet pathway and the E-photoenol in the whole temperature range in methanol solution. A higher quantum efficiency in heated methanol is explained by enhancing the E-photoenol population. This picture was partially confirmed by the quantum chemical calculations. The 2,5-dimethylphenacyl chromophore is proposed as an efficient photoremovable protecting group for carboxylic acids in solutions under conventional or microwave-assisted heating for applications in organic synthesis, such as the solid-phase synthesis.

Links

GA203/02/0879, research and development project

Name: Vliv mikrovlnného záření na fotochemické reakce

Investor: Czech Science Foundation, Microwave Irradiation Effect on Photochemical Reactions

MSM 143100005, plan (intention)

Name: Strukturně-funkční vztahy biomolekul a jejich role v metabolismu

Investor: Ministry of Education, Youth and Sports of the CR, Biomolecular Structure-function Relationships and their role in the Metabolism

Detailed Information on Publication Record