Synthesis of sterically hindered phenol-containing phosphorylated isatin derivatives

Design, synthesis, and biological activity of novel ammonium salts containing sterically hindered phenolic fragment and phosphoryl group

“…A convenient approach for the synthesis of new derivatives of sterically hindered phenols that contain a phosphoryl fragment comprises the use of phosphorus-containing 2,6-di-tert-butyl-4-methylene-2,5-cyclohexadienones 34 in reactions with nucleophiles. Stable phosphorus-containing methylenequinones easily react with amines [35][36][37][38][39][40] and aminoacetals 41,42 to give the products of nucleophilic addition in high yields.…”

Dimethyl [(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienylidene)-methyl]phosphonate in reactions with aliphatic diols

“…The reactions of phosphorus-containing 2,6-di-tert-butyl-4methylene-2,5-cyclohexadienones with nucleophiles has been recognized as a convenient approach to prepare spatially hindered phenols containing phosphoryl fragments [2,3]. The stable dialkyl[(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienylidene)methyl]phosphonates readily react with nucleophiles to form the 1,6-addition products [2,4,5].…”