A general solid phase synthesis of 4-substituted quinolinones via Pd-catalyzed cross coupling

A general method for the solid phase synthesis of 4-hydroxy quinolinones and subsequent Pd-catalyzed cross coupling to afford 4-substituted quinolinones has been developed. Conversion of support-bound 4-hydroxy quinolinones to 4-tosyl quinolinones and subsequent treatment with alkyl, aryl, benzylzinc halides, or arylboronic acids in the presence of catalytic amount of Pd(PPh3)4 provides 4-alkyl, aryl, or benzyl quinolinones. This method allows for the introduction of alkyl, aryl, and benzyl groups at the 4-position of the quinolinone ring, and is ideal for parallel and combinatorial chemistry library synthesis.