Macrotricycles synthesis

A relative of the latter class of compounds are the macrotricyclic quaternary ammonium salts which have been reported by Schmidtchen. The bridges may contain either methylenes or ethyleneoxy units and the nitrogens are quaternarized. The underlying principle is to provide a cavity suitable for solvating or at least trapping anions. Schmidtchen presents evidence which suggests the formation of halide inclusion complexes. The synthesis of these molecules is accomplished along more or less traditional lines Such a species is illustrated above as compound 19. 

A good example for such a situation is a recent report on the synthesis of the macrotricyclic core 63 of roseophilin [40,41]- RCM was able to form the rather strained ansa chain of this target molecule only after the cyclization had been biased by a conformational control element X which helps to bring the unsaturated chains closer together and lowers the enthalpic barrier during ring formation (Scheme 18). 

F. Fages, J.-P. Desvergne, H. Bouas-Laurent, J.-M. Lehn, J. P. Konopelski, P. Marsau, and Y. Barrans, Synthesis and fluorescence emission properties of a bis-anthracenyl macrotricyclic ditopic receptor. Crystal structure ofits dinuclear rubidium cryptate, J. Chem. Soc., Chem. Commun. 655(1990). 

A recent example, with references to previous literature, is in nickel(II) template synthesis of macrotricyclic complexes from formaldehyde and triamines, M. P. Suh, W. Shin, S.-G. Kang, M. S. Lah and T.-M. Chung, Inorg. Chem. 28, 1602 (1989). 

E. Graf, J.-M Lehn, Synthesis and ciyptate complexes of a spheroidal macrotricyclic ligand with octahedrotetrahedral coordination. J. Am. Chem. Soc. 1975, 97, 5022-5024. 

Hammershoi, A., and Sargeson, A.M. Macrotricyclic hexaamine cage complexes of cobalt(III) synthesis, characterization, and properties, Inorg. Chem. 22 (1983), 3554-3561. 

The first synthesis of the macrotricyclic core of roseophilin was carried out by A. Furstner and co-workers. intramolecular Friedel-Crafts acylation was used to close the third ring of the macrotricycle. 

Furstner, A., Weintritt, H. Total Synthesis of the Potent Antitumor Agent Roseophilin A Concise Approach to the Macrotricyclic Core. J. Am. Chem. Soc. 1997, 119, 2944-2945. 

Synthesis of diaza-polyoxa-macrobicyclic compounds (cryptands) and spherical macrotricycles ligands (supercryptands) (see 1st edition). 

Due to the prevalence and diversity of pyrrole and indole alkaloids and the limitations of space, no attempt will be made to describe all of the synthetic efforts in this area. Of those syntheses wherein the construction of a pyrrole ring was of major importance, most efforts were devoted to the marine polycyclic aromatic lamellarin class of alkaloids and total syntheses of lamellarins-D, -G, -K and -O <97X5951, 97AGE155, 97CC2259, 97CC207> were reported Although not a total synthesis, Furstner reported a Pd-mediated route to the macrotricyclic core of the anti-leukemia alkaloid, roseophilin <97JA2944>. 

This route involves three successive cyclisations under high dilution conditions which limits the scale and yield of the overall synthesis severely. The parent macrotricyclic tertiary amines were obtained in 2-5 % overall yield and were quatemized under selected conditions giving the target structures 23-25 uncontaminated by in-out isomers. 

Fages. F. Desvergne, J.-P. Bouas-Laurent. H. Lehn, J.-M. Barrans. Y. Marsau, P. Meyer. M. Albrecht-Gary, A.-M. Synthesis, stmctural. spectroscopic, and alkali-metal cations complexation studies of a bis-anthracenediyl macrotricyclic ditopic receptor. J. Org. Chem. 1994. 59. 5264-5271. 

Fujita, T. Lehn, J.-M. Synthesis of dome-shaped cyclo-phane-type macrotricyclic anion receptor molecules. Tetrahedron Lett. 1988, 29, 1709-1712. 

Extensive studies on metal (Ni or Fe) promoted oxidative dehydrogenations of this and related systems have been reported, the latter paper containing a note on the nomenclature of these complexes which appears to have become rather confused. Related complexes,a new synthesis of cyclam as its Ni complex, and an investigation of Li salt complexes of cyclam by i.r. measurements have also been reported. Mononuclear cryptates, with a wide variety of metal iodides and chlorides, and dinuclear cryptates, with AgN03 and HCOgTl, involvingthe macrotricyclic ligand (500) are discussed. 8i... 

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