Porphyrin-cyclodextrin conjugates

Highly conjugated systems, such as a hydrophilic porphyrin, can be appended to a 8-cyclodextrin conjugate system utilizing excess NaBH3CN as the reducing agent (eq 36). ... 

A number of examples of the use of host-guest chemistry in the creation of PET active systems have appeared. The reaction of P-cyclodextrin alcoholate with meso-tetrakis(pentafluorophenyl)porphyrin is reported to give a hydrophilic cyclodextrin-porphyrin conjugate in 14% yield. ° In the presence of guests such as 1,4-benzoquinone, anthraquinone-2-sufonate or 8-anilino-l-naphthalene sulfonic acid, PET operates as evidenced by the fluorescence... 

Not only the porphyrins having binaphthyl groups, strapped type metalloporphyrins are also able to catalyze asymmetric epoxidation. For example, Mansuy et al. synthesized a "Basket-Handle" iron porphyrin bearing L-phenylalanine residues (Fig. 11(d)) [297]. Collman et al. employed threitol-strapped Mn porphyrins (Fig. 11(e)) [298]. Metalloporphyrin complexes conjugated with glycosylated groups [299], p-cyclodextrin [300], and camphanoyl groups [301] were also prepared. These chiral metalloporphyrin complexes were shown to catalyze asymmetric oxidations. 

The following discussion is intended to provide an introduction to the latest innovations in the design and synthesis of chiral carbon-rich macrocycles while providing some historical context of their development and applications. The systems under review are limited primarily to chiral macrocycles that are conjugated or that possess highly conjugated substructures. Excluded from the discussion are, for example, porphyrins [2, 3], cyclodextrins [4] and calixarenes [5], either because they do not fit within the context of our discussion or because they have been extensively reviewed elsewhere. 

Ikeda et al. and Konishi et al. reported on a supramolecular photocmrent generation system in combination with electrostatic and van der Waals interactions. In a Ceo-porphyrin bilayer prepared by electrostatic alternate adsorption (Fig. 27), the quantum yield of photocurrent generation is increased when self-aggregation of porphyrins is suppressed by host-guest interaction of cyclodextrin and porphyrin [104-106]. Cationic fullerene and tetracationic porphyrin bound on a DNA scaffold by electrostatic interactions was fabricated by conjugate polymer (Fig. 28). The quantum yield of photocurrent generation was 3.8% [107]. 

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