Betti Reaction of Cyclic Imines with Naphthols and Phenols - Preparation of New Derivatives of Betti's Bases

A large library of aminocycloalkylphenols and -naphthols is obtained by the Betti reaction between activated phenols and naphthols and five- and six-membered cyclic imines. Due to the formation of an intramolecular hydrogen bond in the transition state, the attack takes place regioselectively at the position adjacent to the hydroxy group of the aromatic compounds. X-ray crystallography and chirooptical methods (electronic circular dichroism) were used to ascertain the absolute configuration of two aminoalkylnaphthols obtained, after resolution of the corresponding racemates with (R,R)- tartaric acid. In addition, some aminoalkylnaphthols and -phenols were alkylated at the nitrogen atom to obtain Nmethylated products in good yields.