Electrolytic Reactions of Fluoroorganic Compounds. 14. Regioselective Anodic Methoxylation of N-(Fluoroethyl)amines. Preparation of Highly Useful Fluoroalkylated Building Blocks
摘要:
Anodic methoxylation of various types of N-(fluoroethyl)amines, ArRNCH(2)R(f) (R(f) = CF3, CHF2, CH2F, etc.) has been systematically studied and it was found that a methoxy group was exclusively or preferentially introduced into the position a to the fluoromethyl (R(f)) group, depending on the R(f) and R groups. The effect of the R(f) group on the promotion of the anodic alpha-methoxylation decreased in the order CF3, CHF2, and CH2F. This remarkable promotion effect and unique regioselectivity can be explained mainly in terms of the alpha-CH kinetic acidities of the cation radicals formed by one-electron oxidation of the amines. The alpha-methoxylated products are highly useful precursors for the construction of carbon-carbon bonds alpha to the trifluoromethyl and difluoromethyl groups, which is difficult by other methods.
A Difluoromethylation Reagent: Access to Difluoromethyl Arenes through Palladium Catalysis
作者:Xia Chen、Yining Liu、Sheng Zhang、Yang Li、Xiao-Yu Zhou、Xiaoqiang Yu、Xiujuan Feng、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.orglett.4c02161
日期:2024.7.19
A new radical difluoromethylation was developed by using inexpensive and readily available difluoroacetic anhydride and N-phenyl-4-methylbenzenesulfonamide for the first time. The reaction of arylboronic acids with the new difluoromethylation reagent, N-phenyl-N-tosyldifluoroacetamide, proceeded smoothly in the presence of palladium catalyst to provide difluoromethylarenes in satisfactory to excellent