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[reaction: see text] An improved methodology for the N-alkylation of the porphyrin isomer N-confused porphyrin is presented. The combination of polar solvent conditions and the use of the base Cs2CO3 affords externally modified products in high yield without separation difficulties and without the use of large excesses of alkylating reagent. The further transformation and metalation of these products provides opportunities for the construction of metalloenzyme model complexes, peptide adducts, and chromophore assemblies.

A manganese(III) complex of tetraphenylporpholactone, Mn(TPPL)Cl, was synthesized and characterized, including by single-crystal X-ray diffraction; the catalytic activity of this complex for olefin epoxidation reactions is compared with that of manganese(III) tetraphenylporphyrin chloride, Mn(TPP)Cl.

The reactions of ammonia, pyridine (py), N-methyl imidazole (N-MeIm), tetrahydrothiophene (tht), and piperidine (pip) with Re(CO) 3(H 2O) 3 (+), 1 ( + ), were investigated employing aqueous conditions under atmospheric dioxygen. The reaction of [ 1]Br in aqueous ammonia led to [Re(CO) 3(NH 3) 3]Br ([ 2]Br) as the only product isolated. For the aqueous reactions of [ 1]Br with py, N-MeIm, and tht, mixtures of products are formed because of competition between the bromide and added ligand, even when the ligand is present in excess. Substitution of the PF 6 (-) anion for Br (-) leads to the clean formation of [Re(CO) 3L 3][PF 6] ([ 3][PF 6]-[ 5][PF 6]) for py, N-MeIm, and tht, respectively, as the only products observed. Reaction of [ 1][PF 6] with pip produces the dimeric species, (pip)(CO) 3Re(micro-OH) 2Re(CO) 3(pip), 6. Reactions of [ 1]Br were also performed in methanol for comparison purposes. The reaction with pip in this solvent led to the analogous dimer, (pip)(CO) 3Re(micro-OMe) 2Re(CO) 3(pip), 7; however, reactions with py, N-MeIm, and tht gave Re(CO) 3L 2Br, 8- 10, respectively, as the only products. The crystal structures of compounds [ 2]Br- 10 are reported.