oxygen; 1,8-diazabicyclo[5.4.0]undec-7-ene; 13,17-bis(2-carboxylatoethyl)-3,8-bis[1-hydroxyethyl]-2,7,12,18-tetramethylporphine in tetrahydrofuran T=0°C; 0.5 h; Irradiation;

4-methyl-morpholine; isobutyl chloroformate in tetrahydrofuran T=20°C; 3 h;

oxygen; 1,8-diazabicyclo[5.4.0]undec-7-ene; hematoporphyrin IX in tetrahydrofuran T=0°C; 0.5 h; Irradiationwithout DBU; Mechanism;