Conjugation, Substituent, and Solvent Effects on the Photogeneration of Quinone Methides

Autor:	Filippo Doria, Alberto Lena, Riccardo Bargiggia, Mauro Freccero
Rok vydání:	2016
Předmět:	010405 organic chemistry Singlet oxygen Organic Chemistry Solvation Substituent Conjugated system 010402 general chemistry Photochemistry 01 natural sciences Quinone methide 0104 chemical sciences Quinone chemistry.chemical_compound chemistry Flash photolysis Solvent effects
Zdroj:	The Journal of Organic Chemistry. 81:3665-3673
ISSN:	1520-6904 0022-3263
DOI:	10.1021/acs.joc.6b00331
Popis:	4- and 5-arylethynyl water-soluble Mannich bases and related quaternary ammonium salts were synthesized and investigated as a model of conjugated quinone methide precursors (QMPs) by UV-vis light activation. Preparative photohydration and trapping reactions by thiols were studied, together with the detection of both transient QMs and competing QMP lowest triplet excited states (T1), by laser flash photolysis. The efficiency of the arylethynyl derivatives as QMPs was remarkably affected by structural features (i.e., conjugating arylethynyl moieties, substituents, and leaving groups) and protic vs aprotic solvation. Our collective data clarify the dichotomy in the photoreactivity of conjugated Mannich bases and related quaternary ammonium salts as alkylating agents and singlet oxygen sensitizers.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d26c70552165f55f96443bcd6028ee68 https://doi.org/10.1021/acs.joc.6b00331 Zobrazit plný text záznamu