Rational synthesis of meso- or β- fluoroalkylporphyrin derivatives via halo-fluoroalkylporphyrin precursors:: Electronic and steric effects on regioselective electrophilic substitution in 5-fluoroalkyl-10,20-diarylporphyrins

Electrophilic nitration, formylation or bromination of metalated 5-fluoroalkyl-10,20-diphenylporphyrin (fluoroalkyl = CF3, ClCF2ClCF2, n-C6F13) proceeded with high regioselectivity, exclusively affording corresponding meso-substituted porphyrins, while the iodination reaction mainly took place at the adjacent site giving 2-iodo-10-fluoroalkyl-5,15-diphenylporphyrin. Suzuki, Sonogashira, and trifluoromethylation reactions of the obtained 5-bromo-15-fluoroalkyl-10,20-diphenylporphyrins or 2-iodo-10-fluoroalky-15,15-diphenylporphyrins could perform smoothly to give the corresponding various meso- or beta-functionalized fluoroalkylated porphyrin derivatives. Accordingly, two meso-to-meso butadiyne-bridged bisporphyrin dimers and two beta-to-beta butadiyne-linked dimeric porphyrins were prepared by the coupling reactions of 5-ethynyl-15-fluoroalkyl-10,20-diphenylporphyrins and 2-ethynyl-lo-fluoroalkyl-5,15-diphenylporphyrins, respectively.