Umemoto Reagent I

CAS 131880-16-5, Cat. No EN300-18527578

Reagent for trifluoromethylation

Umemoto reagent I is an electrophilic trifluoromethylating agent used for transferring the trifluoromethyl group to nucleophiles such as silyl enol ethers and β-ketoesters¹. It is also employed in catalytic strategies including Pd-catalyzed aromatic C-H trifluoromethylation, Cu-catalyzed trifluoromethylation, and photoredox-catalyzed radical trifluoromethylation². The reagent is a white crystalline solid that should be stored in a cool, dry place due to its potentially harmful properties.

Synonyms: S-(trifluoromethyl)dibenzothiophenium tetrafluoroborate; Umemoto’s reagent I; 5-(trifluoromethyl)-5H-dibenzo[b,d]thiophen-5-ium tetrafluoroborate; 5-(trifluoromethyl)dibenzothiophen-5-ium, tetrafluoroborate

Selected publication

1. Exploration of Fluorination Reagents Starting from FITS Reagents.Umemoto T. J Fluor Chem 2014, 167, 3–15. DOI: 10.1016/j.jfluchem.2014.07.029

2. S-(Trifluoromethyl)Dibenzothiophenium Tetrafluoroborate.Riou M.; Koike T. Encyclopedia of Reagents for Organic Synthesis 2018, 1–3. DOI: 10.1002/047084289X.rn01212.pub2