Ugi four-component condensation (Ugi-4CC) between 2-formylbenzoic acid, phenacylamine dimethyl acetal, and isocyanides afforded 1H-isochromen-1-ones (isocoumarins). These products, where structure corresponds to the tautomeric enediamine form of the Ugi-4CC primary adducts, were stable enough to allow their isolation and characterization. Stable isocoumarins were also obtained by employing anilines as the amino component in the Ugi four-component condensation.
Synthesis of diverse phenylglycine derivatives via transformation of Ugi four-component condensation primary adducts
3-(N-Substituted)amino-4-arylamino-1H-isochromenones (isocoumarins) which can be regarded as the enediamine tautomers of the Ugi four-component condensation primary adducts between 2-formylbenzoic acids, arylamines, and isocyanides undergo a facile ring cleavage with amines to give a series of phenylglycine derivatives. Thus, a synthetically useful post-condensation transformation of Ugi four-component
Reaction of isonitriles with 3‐(arylamino)isobenzofuran‐1(3H)‐ones in the presence of a catalytic amount of an octahydro (R)‐binol‐derivedchiral phosphoric acid afforded 3‐oxo‐2‐arylisoindoline‐1‐carboxamides in high yields with good to high enantioselectivities. An enantioselective Ugi four‐center three‐component reaction of 2‐formylbenzoic acids, anilines, and isonitriles was subsequently developed