Chang, Christopher J. Yeh, Chen-Yu Nocera, Daniel G. Porphyrin Architectures Bearing Functionalized Xanthene Spacers A modular synthetic strategy for the construction of cofacial porphyrin architectures bearing hydrogen-bond synthons on a xanthene platform is presented. The convergent approach is based on a xanthene aldehyde-ester building block that is easily obtainable on a multigram scale with minimal purification. Treatment of this xanthene derivative with a variety of aryl aldehydes and pyrrole under standard Lindsey conditions affords a family of <i>meso</i>-substituted porphyrins bearing a single functionalized xanthene spacer. Direct modification of the hydrogen-bond synthon after macrocyclization proceeds smoothly to furnish porphyrin systems with a variety of cofacial functionalities (e.g., carboxylic acid, ester, amide). Porphyrins bearing two <i>trans</i>-functionalized xanthene spacers are prepared by the MacDonald [2 + 2] condensation of the xanthene aldehyde-ester with readily available 5-aryl-substituted dipyrromethanes such as 5-mesityldipyrromethane to afford the pure α,α- and α,β-porphyrin atropisomers after chromatographic separation. The versatility of this synthetic method offers intriguing opportunities for the use of these and related templates for the study of proton-coupled activation of small molecules. multigram scale;Lindsey conditions;functionalized xanthene spacers;cofacial porphyrin architectures;functionalized xanthene spacer;xanthene platform;aryl aldehydes;cofacial functionalities;Direct modification;convergent approach;Porphyrin Architectures Bearing Functionalized Xanthene Spacers;porphyrin systems;macrocyclization proceeds 2002-01-30
    https://acs.figshare.com/articles/journal_contribution/Porphyrin_Architectures_Bearing_Functionalized_Xanthene_Spacers/3692280
10.1021/jo016095k.s001