Site-Selective Tertiary Alkyl-Fluorine Bond Formation from α-Bromoamides Using a Copper/CsF Catalyst System.
A copper-catalyzed site-selective fluorination of α-bromoamides possessing multiple reaction sites, such as primary and secondary alkyl-Br bonds, using inexpensive CsF is reported. Tertiary alkyl-F bonds, which are very difficult to synthesize, can be formed by this fluorination reaction with the aid of an amide group. Control experiments revealed that in situ generated CuF2 is a key fluorinating reagent that reacts with the tertiary alkyl radicals generated by the reaction between an α-bromocarbonyl compound and a copper(I) salt.
Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi, 755-8611, Japan. nisikata@yamaguchi-u.ac.jp.
Takashi
T
Nishikata
Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi, 755-8611, Japan.
Syo
S
Ishida
Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi, 755-8611, Japan.
Ryo
R
Fujimoto
alkylation; copper; fluorination; radicals; reaction mechanisms