Unexpected formation of polysubstituted 1-azabutadienes and 1,3-dioxanes from the reaction of 3-fluoroalkyl-3-arylaminoacrylic acid esters with formaldehyde.
[reaction: see text] The reaction of 3-fluoroalkyl-3-arylaminoacrylic acid esters with formaldehyde was described. In the presence of a catalytic amount of triethylamine, the reaction took place readily in acetonitrile at 70 degrees C to give the corresponding 2-fluoroalkyl-1-azabutadienes in good yields. cis-Fluoroalkylated 1,3-dioxanes were obtained predominantly when the aryl ring contained an electron-withdrawing group and the reaction was carried out at room temperature under catalysis of triethylamine and tetrabutylammonium bromide. A possible mechanism was proposed.
Zhao
Fu-Lu
FL
Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
Liu
Jin-Tao
JT