Chemistry of Organo Halogenic Molecules. Part 229. The Role of Iodine in Acetyl Group Transfer to Oxygen-containing Molecules under Solvent-free Reaction Conditions

摘要

Iodine was shown to be an efficient catalyst for the conversion of phenyl-substituted aldehydes to the corresponding 1,1-diacetate derivatives under solvent-free reaction conditions (SFRC),which are superior to the classical solution conditions. It was demonstrated that the order of the addition of reactants was of fundamental importance;the ability of substituents on the phenyl ring modified reactivity irrespectively to electronic properties,the pentafluorophenyl group significantly reduced reactivity of the aldehyde. Alcohols yielded acetates;acetic anhydride was found to be the most efficient reagent;isopropenyl acetate and vinyl acetate were less reactive;however the pentafluorophenyl group enhanced reactivity with the latter two reagents. Beside the esterification of benzyl alcohol and its pentafluorophenyl analogue,the formation of acetals was also observed.