Synthesis and properties of calixarene analogs incorporating a thiophene unit in the macrocyclic ring

Calixarene analogs containing a thiophene unit in the macrocyclic ring were prepared by a stepwise method. The macrocycles adopt a cone‐like form as the preferred conformation in solution. The induced chemical shift change, nOe experiment, and ¹H relaxation time (T₁) measurement supported the fact that the macrocycle forms a complex with the N‐methylpyridinium salt. In contrast, O‐tetramethylated macrocycles and linear phenol‐formaldehyde tetramer, could not efficiently include the N‐methylpyridinium salt.     

Synthesis of macrocyclic compounds containing thiophene and thiazole nuclei

Macrocyclic ketones that contain a thiophene nucleus and have 14 or more carbon atoms in the ring can form systems with a condensed thiazole ring, in high yield.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 841–844, June, 1986.     

Unexpected conversion of a polycyclic thiophene to a macrocyclic anhydride

Oxygenation of 2,5,9,12-tetra(tert-butyl)diacenaphtho[1,2-b:1′,2′-d]-thiophene (1, C₄₀H₄₄S) by peracids gave the cyclic sulfonic ester 4 (2,7,10,13-tetra(tert-butyl)diacenaphtho[1,2-c:1′,2′-e]oxathiin 5,5-dioxide, C₄₀H₄₄O₃S) which, when heated in nitrobenzene, is converted into a complex, macrocyclic anhydride 3 (C₈₀H₈₈O₃), which is derived from two molecules of 4. Further investigation found a likely intermediate in this reaction, 4,4′,7,7′-tetra(tert-butyl)-1,1′-biacenaphthylenylidene-2,2′-dione (5, C₄₀H₄₄O₂), apparently formed from 4 by additional oxidation. Anhydride 3 plausibly arises by Diels-Alder reaction of 4 and 5 followed by several ring fragmentations. The structures of 3, 4, and 5 were unambiguously established by X-ray crystallography.     

Fragmentation of the macrocyclic ring of alkaloids with the otonecine nucleus

Summary It has been shown that the fragmentation of the macrocycle of the otonecine bases qualitatively resembles the decomposition of macrocyclic alkaloids with the retronecine skeleton. The presence of an oxygen-containing substituent at C₅ and of an alkoxy group at C₂, when there is no C₅=C₆ double bond, substantially changes the direction of decomposition of the macrocycle.A similarity of the spectra of 11- and 12-membered bases with similar mutual orientation of CH₃ groups at C₂ and C₃ has been noted.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–71, January–February, 1976.     

Condensed heteroaromatic systems including a thiophene ring

A number of complexes based on 3-hydroxy-2-benzo[b]formylthiophene and its Schiff bases were obtained and investigated as stabilizers for polycaproamide fibers. It was established that {N,N-bis(3-hydroxy-2-benzo[b]thenylidene)ethylenediaminato}-copper (II) which makes it possible to simultaneously improve the thermal stability and photostability of polycaproamide fibers, is the most effective stabilizer of the investigated compounds.     

Novel macrocyclic templates by ring enlargement of ansa-steroids

Ring enlargement of ansa-steroids leads to a variety of novel templates which are suitable for the preparation of diverse libraries of natural product derivatives. Key steps for the synthesis of these highly functionalized templates were either an ozonolysis-derivatization-ring closing metathesis-sequence or a macrolactonization.     

Synthesis of macrocyclic compounds that are condensed with a pyrazole ring

2-Carbethoxy-[11]--cyclothien-1-one, 2-carbethoxycyclopentadecanone, and 2,15-dicarbethoxy-[9,9]--cyclodithiene-1,14-dione were converted to 2-phenyl-1-methyl-[11]--cyclothieno [1,2-d] pyrazol-3-one, 2-phenyl-1-methyl-4,5-tridecamethylenepyrazol-3-one, and 2,16-diphenyl-1, 15-dimethyl- [9,9]-, -cyclodithienobis [(1,2-d, 14,15-d) pyrazole]-3,17-dione, respectively, by condensation with phenylhydrazine and subsequent methylation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 920–923, July, 1980.     

Synthesis of macrocyclic imides by one-step ring enlargement

By one-step ring-enlargement reaction with isocyanates, 2-cyano- and 2-(ethoxycarbonyl)-substituted cycloalkanones are converted into macrocyclic imides.     

Condensed heteroaromatic systems that include a thiophene ring

New complexing compounds, viz., 2-formylbenzo[b]thiophene-3-selenol and 3-formylbenzo[b]-thiophene-2-selenol, and some derivatives involving the selenium atom and the formyl group, as well as complexes of divalent nickel and copper based on them, were obtained. The tautomerism of the isomeric formylthiopheneselenols was studied by means of IR spectroscopy, and it was shown that 3-formylbenzo[b]thiophene-2-selenol, in contrast to 2-formylbenzo[b]thiophene-3-selenol, exists in the form of a mixture of two tautomers.See [1] for communication 35.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 898–904, July, 1979.     

Condensed heteroaromatic systems including a thiophene ring.

The thermal stabilities of 2-mercapto-3-formylbenzo[b]thiophene and its chelates with Cu(II) and Co(II), of 2-mercapto-3-iminomethylbenzo[b]thiophene and its chelates with Cu(II), Co(II), Ni(II), and Zn(II), and of N,N′-bis(2-mercaptobenzo [b]-3-thenylidene)ethylenediamine and its chelates with Cu(II), Co(II), and Ni(II) were investigated by differential-thermal and thermogravimetric analysis. The temperature of the onset of decomposition and the character of the decomposirion of the ligands and chelates were established. It was found that the investigated chelates can be arranged in the following order with respect to increasing thermal stability: Cu < Co < Zn < Ni. The most thermally stable ligand is N,N-bis (2-mercaptobenzo[b]-3-thenylidene)ethylenediamine. The effectiveness of the ligands and chelates as stabilizers for polycaproamide fibers were compared. It was found that of the investigated compounds, the copper chelates are effective stabilizers. In a study of the thermal behavior of the copper chelates in an inert gas atmosphere it was established that the character of the thermal decomposition of the most effective of them — {it(N,N′-bis)2-mercaptobenzo[b]-3-thenylidene)-ethylenediaminato} Cu(II) — is identical both in the presence of air oxygen and in a nitrogen atmosphere, i.e., the chelate does not undergo oxidation at temperatures up to 270?C.