Release Time:2021-04-26  Hits:

Indexed by: Journal Article

Date of Publication: 2021-01-30

Journal: JOURNAL OF ORGANIC CHEMISTRY

Volume: 83

Issue: 21

Page Number: 13051-13062

ISSN: 0022-3263

Key Words: Density functional theory; Ketones; Light, Aerobic epoxidation; Flow synthesis; Photoepoxidation; Singlet oxygen; Tetramethylguanidine; Unsaturated ketones; Visible light; Visible light induced, Molecular oxygen, amidine; chalcone; guanidine derivative; ketone derivative; oxygen; photosensitizing agent; porphyrin derivative; singlet oxygen, aerobic metabolism; Article; chemical structure; density functional theory; epoxidation; light; photooxidation; proton nuclear magnetic resonance; reaction analysis; reaction optimization; screening; synthesis

Abstract: An aerobic photoepoxidation of alpha,beta-unsaturated ketones driven by visible light in the presence of tetramethylguanidine (3b), tetraphenylporphine (H2TPP), and molecular oxygen under mild conditions was revealed. The corresponding alpha,beta-epoxy ketones were obtained in yields of up to 94% in 96 h. The reaction time was shortened to 4.6 h by flow synthesis. The mechanism related to singlet oxygen was supported by experiments and density functional theory (DFT) calculations.