Microwave-Assisted Synthesis of α-Amino Phosphonates Derived from Formylporphyrins of Natural Origin

The first synthesis of α-amino phosphonates comprising porphyrin core was accomplished. Three methods of obtaining α-amino phosphonates 5-8 were compared. Conventional heating of formylporphyrins 1-4 with t-BuNH 2 and (EtO) 2 P(O)H in various solvents was ultimately unsuccessful for preparing 5-8 whereas the use of microwave irradiation made it possible to obtain 5-8 in good yields. Regioselective preparation of 5-8 in excellent yields was achieved by combining microwave-assisting conditions and catalysis with CdI 2 . Efficient synthetic procedures of obtaining formylporphyrins 3,4 in large scale were also proposed.