synthesis of organophosphorus compounds and their applications in organic synthesis; catalytic properties of organophosphines in organic synthesis; solid catalysts in organic synthesis; synthesis of organosulfur compounds; structure elucidation; organic synthesis in aqueous media; organic synthesis in solvent-free conditions; organic synthesis under microwave irradiation; applied chemistry; natural products chemistry; phothochemistry; medicinal chemistry; heterocyclic chemistry; Wittig reaction; invention of reactions