One-Pot Multicomponent Synthesis of Thiourea Derivatives in Cyclotriphosphazenes Moieties

In this study, hexasubstituted thiourea was carried out via reaction of isothiocyanato cyclophosphazene intermediates with a series of aromatics amines and amino acids in a one-pot reaction system. The reaction was not as straightforward as typical thiourea synthesis. Six unexpected thiourea derivatives 3a-f were formed in the presence of cyclotriphosphazene moieties in good yields (53-82%). The structures of 3a-f were characterized by elemental analysis and FTIR, H-1, C-13, and P-31 NMR spectroscopies. The occurrence of reverse thioureas formation in a one-pot reaction system is discussed. The possible binding interaction of the synthesised thiourea 3a-b in comparison to the predicted phenyl thiourea 5a-b and the targeted 4a with enzyme enoyl ACP reductase (FabI) is also discussed. Molecular docking of the targeted hexasubstituted thiourea 4a is able to give higher binding affinity of -7.5 kcal/mol compared to 5a-b (-5.9 kcal/mol and -6.3 kcal/mol) and thiourea 3a-b (-4.5 kcal/mol and -4.7 Kcal/mol).