Functionalized heterocycle-appended porphyrins: catalysis matters

Abstract

The condensation of labile 2,3-diaminoporphyrins with aromatic aldehydes is a versatile technique for the elaboration of functionalized porphyrins. The acidic catalyst in the reaction is a tool that allows the reaction path to be switched.

Ammonium Imidazoporphyrin – a Newborn in a Family of Porphyrins for Hybrid Materials

“…[19,20] In turn, our recent developments in this field were aimed on the targeted introduction of various functional units to the heterocyclic fragments with special emphasis to anchoring groups. [21][22][23] Following the idea of development of cost-efficient porphyrin-based hybrid materials we considered commercially available silica as a promising inert solid support and ammonium fragment as a convenient anchoring group. Thus, in the present work we have focused on the synthesis of a new heterocycle-appended porphyrin, bearing peripheral ammonium anchoring unit (Figure 1).…”

“…Nevertheless, the obtained yield of 6 is in fine consistency with the yield of the related phenoxyl substituted imidazoporphyrin. [21] The next synthetic step was conducted with the transformation of OH-group of 6 to a good leaving group. We attempted to perform its substitution to bromine atom by means of Appel reaction, [27] which typically proceeds with high yields.…”

Efficient Approach to Functionalized β-Imidazolylporphyrins

“…[18][19][20][21] In this respect the formation of the imidazole heterocycles was shown to be a convenient approach for the conjugation of porphyrins and peripheral coordination centers. [18,22,23] Thus, we have successfully generalized the approaches for the preparation of functionalized meso-imidazolyl-, [19,24] imidazo-, [18,25,26] -pyrazino-, [22,27,28] and expanded pyrazino-derivatives. [29] In the present work we focused on the determination of the application scope of Debus-Radziszewski condensation for the preparation of a series of porphyrins containing functional -imidazolyl-substituents.…”