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Visible‐Light‐Driven Fluoroalkylation of Tryptophan Residues in Peptides
Author(s) -
Rahimidashaghoul Kheironnesae,
Klimánková Iveta,
Hubálek Martin,
Matoušek Václav,
Filgas Josef,
Slavíček Petr,
Slanina Tomáš,
Beier Petr
Publication year - 2021
Publication title -
chemphotochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 18
ISSN - 2367-0932
DOI - 10.1002/cptc.202000214
Subject(s) - chemistry , tryptophan , reagent , radical , cysteine , photochemistry , amino acid , catalysis , aqueous solution , combinatorial chemistry , organic chemistry , enzyme , biochemistry
Trifluoromethylated and fluoroalkylated cyclic λ 3 ‐iodanes and their acyclic salts were used for visible light‐driven fluoroalkylation of tryptophan and tryptophan‐containing peptides in aqueous media. In comparison to previously reported fluoroalkylation using similar reagents and sodium ascorbate as reductant, the photochemical process did not require any additive or catalyst and was more selective for Trp versus other aromatic amino acids due to the gradual production of fluoroalkyl radicals over the whole irradiation period. However, in the presence of Cys residues, both methods were not selective and cysteine sulfhydryl groups were fluoroalkylated in side reactions. Spectroscopic and photochemical investigations as well as quantum chemical calculations provided insight into the reaction mechanism. The process was found to be photoinduced involving the formation of fluoroalkyl radical from the excited state of λ 3 ‐iodane.