Macrocycles mixed

The mixed macrocyclization of the bifunctional benzenebis(l,3-diiminopyrroline) (138) with an excess of bis(dimethylamino)maleonitrile... 

Additional unsymmetrical porphyrazinols have also been reported. The mixed macrocyclization of the dispiroketal substituted dinitrile (188) with di-terf-butyl phenyl pyrroline (68) gives Mg[pz(AB3)], A = dispiroketal, B = di-terf-butyl phenyl (194) in 30% yield, which can be demetalated with glacial acetic acid to... 

Synthesis. Comacrocyclization of 2,5-diiminopyrrolidine (213) with 5 equiv of bis(dimethylamino)maleonitrile (99) produced 214. Subsequent demetalation with TFA gave 215 in 5% overall yield. Similarly, mixed macrocyclization of 2,5-diiminopyrrolidine 213 with 2,3-dipropyl-maleonitrile (33) produced pz 216 (3%). The yield of this reaction could be improved by conversion of dinitrile (33) into the diiminopyrroline derivative 212 using ammonia, to provide pz 216 in 17% yield. Demetalation of 216 furnished the free base 217 (91%). 

Analogously, complex 218 was prepared by mixed macrocyclization of 2,5-diiminopyrrolidine (213) with ferf-butylphenylpyrroline (68) in 19% yield. The free base (219) (95%) was obtained by demetalation of magnesium complex 218 with trifluoroacetic acid and subsequent remetalation of 219 with Ni(OAc)2 gave the corresponding nickel complex 220 in 98% yield. 

Plate 25 (Figure 3.19). Space-filling representation of hexamer 12, or mixed macrocycle 11, viewed along the 3 bar axis of the capsule. 

A number of mixed macrocycles have been prepared. A template requirement has not been established unless the sodium ion serves to coordinate to sulfur and oxygen in the reaction of cyclic vicinal mercaptophenols or dithiols with equivalent proportions of terminal-substituted ether dichlorides in the presence of sodium hydroxide (109) and in the reaction of 1,2-dibromoethane with the disodium salt of 3-oxapentane-1,5-dithiol at high dilution (15). Macrocycles XCVI-XCVIII were prepared by the former route, and XCIX, in low yield due to extensive polymerization, by the latter. 

The neutrally charged /x-nitrido dimer of TPPFe, [(TPPFe)2N] and its phthalocyanine " " and mixed-macrocycle counterparts, are isoelectronic with the TT-cation radical of the /x-oxo dimers discussed above, but they have a different electron configuration. " NMR shifts are more consistent with their description as delocalized system having two Fe + rather than a delocalized porphyrin TT-cation radical. This complex readily reacts reversibly with dioxygen to produce an EPR-active species that has... 

Fig. 34 Solid-state structure of the mixed-macrocycle hexameric capsule. Diethyl ether guests are shown in dark gray.

Using the same general strategy described above. Beer reported the first anion-templated synthesis of catenanes [43,44]. Mixing macrocycle 21 with... 

Mixed macrocycles based on thiophenes and other unsaturated units Mixed macrocycles based on -substitution in thiophene units... 

Nitschke and Tilley developed a very effective synthesis of zirconacyclopentadiene-coupled macrocycles [414]. One of the examples was reacted with disulfur dichloride to give mixed macrocycle 4.41 in which three 3,4-thienylene units are connected by p-phenylene units and are responsible for cross-conjugation (Chart 1.54). 

Ciszevski and Milczarek reported roughly similar oxidation onset potentials for methanol and ethanol in 0.1 M NaOH using Ni(II) tetrakis(3-methoxy-4-hydroxyphenyl) porphyrin film (poly-NiTMHPP). However, they explored catalytic oxidations up to 0.5 M methanol concentration [207]. Since the alcohol electrooxidation occurs at potentials more positive than the redox potential of Ni(III)/Ni(II) (i.e., Ni(III) is the electrocatalytically active form), a direction to improve the performance would be to find macrocycles that negatively shift the Ni(III)/Ni(II) potential. Another variant would be to develop mixed macrocycle catalysts by incorporating elements that promote OHad formation, since on Ni polymer films the methanol oxidation was strongly dependent on flie OH" concentration [207]. 

Marsella and coworkers exploited perfluorophenyl-phenyl quadrupole interactions to template the synthesis of a thiophene-containing cyclophane [44]. As shown in Scheme 6.14, when the oligomeric precursors 98-101 were treated with Sonogashira cross-coupling conditions, the mixed perfluorophenyl-phenyl cyclophane 102 was reproducibly achieved in greater yield than either of the symmetrical analogs 103 and 104. Other mixed macrocyclic derivatives were also prepared as part of this study, and their findings with these model systems supported... 

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