5,10,15‐Tris(4‐sulfonatophenyl)corrole Synthesis

Abstract

Two synthetic routes for the preparation of the water soluble 5,10,15‐tris(4‐sulfonatophenyl)corrole are reported. The first approach explores the chlorosulfonation reaction on the phosphorus complex of 5,10,15‐tris(4‐trimethylsilylphenyl)corrole. Following this route, the P complex of the target corrole has been obtained in low yields, while the major product was the tetrasubstituted complex, with the additional sulfonyl group regioselectively introduced at the 2‐position. To widen the scope of the reaction, the direct preparation of the 5,10,15‐tris(4‐sulfonatophenyl)corrole has been pointed out, affording both the target corrole and the intermediate chlorosulfonyl derivative in reasonable yields. The photophysical properties and the protonation equilibria of both corroles have been investigated, showing that 5,10,15‐tris(4‐sulfonatophenyl)corrole does not aggregate in acidic solutions, different from the analogous porphyrin.

Milestones in corrole chemistry: historical ligand syntheses and post-functionalization

“…Scheme 10 Synthesis of 5,10,15-tris(4-sulfonatophenyl)corrole dihydroxyl phosphorus(V) reported by Caroleo and co-workers in 2019 and the chlorosulfonation approach reported in 2001. 66,67 of the sulfonated corrole 14, 5,10,15-tris(4-sulfonatophenyl)corrole dihydroxy phosphorus(V) corrole. 66 The target corrole was obtained in 9% yield by using ClSO 3 Si(CH 3 ) 3 as a sulfonating agent; the major product in this reaction, however, was found to be the tetrasulfonated compound 15, 5,10,15tris(4-sulfonatophenyl)corrole phosphorus(V)dihydroxide (Scheme 10, top).…”

“…Recently, Caroleo and co-workers introduced the synthesis of compounds 13 , 5,10,15-tris(4-trimethylsilylphenyl)dimethoxyl phosphorus corrole, as a precursor for the synthesis of the sulfonated corrole 14 , 5,10,15-tris(4-sulfonatophenyl)corrole dihydroxy phosphorus(V) corrole. 66 The target corrole was obtained in 9% yield by using ClSO 3 Si(CH 3 ) 3 as a sulfonating agent; the major product in this reaction, however, was found to be the tetrasulfonated compound 15 , 5,10,15-tris(4-sulfonatophenyl)corrole phosphorus(V)dihydroxide (Scheme 10, top). This product formation is reminiscent of the very successful procedure reported earlier in 2001–2002 (Scheme 10, bottom), signifying the highly selective “post-functionalization” of the A 3 corrole 10 to the water-soluble bis-sulfonated derivative.…”