Several multicomponent synthetic approaches were elaborated for plenty of novel nitrogen or oxygen heterocycles containing a phosphonate or a phosphine oxide moiety. All multicomponent reactions were optimized through a model reaction in respect of the heating mode, molar ratio of the starting materials, atmosphere, catalyst, temperature, reaction time and solvent applied, and then, the extended preparation of small libraries of structurally-related compounds was performed. Most of the reactions could be considered as "green syntheses", as they were carried out in the absence of any catalyst and/or solvent using microwave (MW) irradiation or even at ambient temperature. The scaling-up of a MW-assisted synthesis was also elaborated in a continuous flow MW system. Altogether more than 150 heterocyclic organophosphorus compounds were synthesized, among them several derivatives showed moderate or promising activity against the HL-60 cell line and Bacillus subtilis bacteria.
Keywords: Biological activity; Heterocycles; Microwave chemistry; Multicomponent reactions; Organophosphorus compounds.