Scheme 1. Synthesis of diphenylphosphine-fused porphyrin 6 (Ar = 3,5-di-tert-butylphenyl). (i) LiPPh₂, THF, room temperature; then, H₂O₂, CH₂Cl₂, room temperature, 56%; (ii) Pd(OAc)₂, PCy₃·HBF₄, tBuCO₂H, K₂CO₃, N,N-dimethylacetamide, 120 °C, 46%; (iii) HSiCl₃, toluene, 110 °C, 65%.