Microwave-Assisted Synthesis and Spectral Properties of Pyrrolidine-Fused Chlorin Derivatives

Abstract

In this work we pursued research involving the microwave-assisted N-alkylation of a NH pyrrolidine-fused chlorin with methyl 4-(bromomethyl) benzoate and subsequent ester hydrolysis as a straightforward strategy to obtain carboxylic acid functionality in the pyrrolidine-fused chlorin, as a single reaction product. We studied the reaction’s scope by extending the N-alkylation of the free-base chlorin and its corresponding Zn(II) complex to other alkyl halides, including 1,4-diiodobutane, N-(2-bromoethyl)phthalimide, and 2-bromoethanaminium bromide. In addition, two new chlorin–dansyl dyads were synthesized by reacting dansyl chloride with the 2-aminoethyl pyrrolidine-fused chlorin (dyad 6) and NH pyrrolidine-fused chlorin (dyad 7). According to spectral studies, the linker length between the two fluorophores influences the response of the dyads to the solvent polarity. Because of the simplicity of these approaches, we believe it will enable access to a vast library of custom-tailored N-functionalized chlorins while preserving their important absorption and emission spectra as photosensitizers in photodynamic therapy (PDT) of cancer and photodynamic inactivation (PDI) of microorganisms.

Recent Progress and Trends in the Development of Electrospun and 3D Printed Polymeric-Based Materials to Overcome Antimicrobial Resistance (AMR)

“…Other approaches involve the use of photosensitizers to achieve photodynamic inactivation (PDI) of several microorganisms. As mentioned in Section 2 , PDI operates under same mechanisms of PDT where photosensitizers generate ROS to destroy essential components of biofilm matrices, both on the cell surface and inside microbial cells [ 101 ].…”

The dual behaviour of β-vinylporphyrins in the presence of α,α′-dioxothiones

“…Previous studies by our and other groups showed that natural and synthetic porphyrins bearing vinyl functionalities are important scaffolds for further functionalization via cycloaddition reactions. 7–14 In particular, we found that 2-VinylTPP reacts with different dienophiles like tetracyanoethylene, dimethyl acetylenedicarboxylate, 1,4-naphthoquinone, and 1,4-benzoquinone affording [4+2] and/or [2+2] adducts and depending on the dienophile, the adducts can undergo further transformations. 10,11,15,16 It was also found that the Zn( ii ) complex of 2-vinyl-5,10,15,20-tetraphenylporphyrin ( Zn-VinylTPP ) can react as a dienophile in Diels–Alder reactions with ortho -quinone methides generated in situ from the reaction of 2-hydroxy-1,4-naphthoquinone, 4-hydroxycoumarins or o -hydroxybenzyl alcohols with paraformaldehyde.…”