Heteroatom Chemistry

Sensfuss, Ulrich; Habicher, Wolf D.

doi: 10.1002/(SICI)1098-1071(1998)9:6<529::AID-HC1>3.0.CO;2-#pmid: N/A

Bicyclic 2‐aminothiophenes 2, which are available by the Gewald reaction of 2,2,6,6‐tetramethyl‐4‐piperidone (triacetonamine, 1), were employed in cyclizations to give new tricyclic thienopyridine and thienopyrimidine derivatives, without protection of the piperidine nitrogen, whereas methylation of 2 occurred exclusively at the piperidine nitrogen. Acylation of 2 in the presence of a tertiary amine yielded N‐thienyl imides, due to the high NH acidity of the intermediate N‐thienyl amides. Similarly, benzylation of an N‐thienyl amide proceeded readily in sodium ethoxide solution. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:529–536, 1998

Wieczorek, Michał W.; Bujacz, Grzegorz D.; Majzner, Wiesław R.; Graczyk, Piotr P.; Mikołajczyk, Marian

doi: 10.1002/(SICI)1098-1071(1998)9:6<537::AID-HC2>3.0.CO;2-1pmid: N/A

The crystal and molecular structures of a pair of diastereomeric 2‐diphenylthiophosphinoyl‐cis‐(4,6‐dimethyl)‐1,3‐dithianes 2 have been determined by the X‐ray method. The differences in corresponding bond distances in cis‐2 and trans‐2 are discussed in context of the anomeric effect operating in this heterocyclic system. The comparison of selected structural parameters between diastereomeric cis‐ and trans‐dithianes 2 and their 5‐t‐butyl analogs 1 is also discussed. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:537–541, 1998

Dolenko, G. N.; Poleshchuk, O. Kh.; Koput, J.

doi: 10.1002/(SICI)1098-1071(1998)9:6<543::AID-HC3>3.0.CO;2-5pmid: N/A

Electron structure changes of SbCl5 on its complexation have been investigated by X‐ray fluorescence spectroscopy and compared with corresponding earlier data for SnCl4L2 and TiCl4L2 complexes. X‐ray spectral data analysis against the data of the heat of formation of the complexes, Mössbauer effect parameters, derivatographic data, and the valence vibration frequences have permitted an assessment of the complex stability against different factors and have proved donor electron density transfer from the donor to the acceptor to be small. It has been shown that the donor charge effect consists mainly of the acceptor bond polarization. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:543–548, 1998

Lin, S. T.; Cheo, H. S.; Chen, B. I.; Own, Z. Y.

doi: 10.1002/(SICI)1098-1071(1998)9:6<549::AID-HC4>3.0.CO;2-#pmid: N/A

C(4), C′(2)‐Double substitution was achieved in good yields by reacting 3‐arylsydnones with BuLi and then with a suitable electrophile in THF at −50°C. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:549–552, 1998

Neda, Ion; Vollbrecht, Alexander; Grunenberg, Jörg; Schmutzler, Reinhard

doi: 10.1002/(SICI)1098-1071(1998)9:6<553::AID-HC5>3.0.CO;2-5pmid: N/A

Unlike C‐undecylcalix[4]resorcinarene, C‐methylcalix[4]resorcinarene 1 reacted with chlorodifluorophosphine in the absence of an auxiliary base to give the unstable octakis(difluorophosphite)‐substituted derivative 2. The existence of two conformational isomers of 2 in solution was observed by 19F and 31P NMR spectroscopy. Attempts to react the octakis(trimethylsilyl)calix[4]resorcinarene 3 and its tetrabromo derivative 4 with phosphorus trichloride and chlorodifluorophosphine were unsuccessful.

Ivonin, Sergei P.; Anishchenko, Andrei A.; Kurochkin, Alexander F.; Tolmachev, Andrei A.

doi: 10.1002/(SICI)1098-1071(1998)9:6<559::AID-HC6>3.0.CO;2-#pmid: N/A

5‐Substituted 2‐furaldehyde dimethylhydrazones react regioselectively with P(III) halides to give, after removal of the hydrazone protection, 3‐phosphorylated 5‐R‐2‐furaldehydes. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 559–563, 1998

Yagupolskii, Yurii L.; Pavlenko, Nataliya V.; Lork, Enno

doi: 10.1002/(SICI)1098-1071(1998)9:6<565::AID-HC7>3.0.CO;2-3pmid: N/A

Novel stable carbanions of the generalformula −C(SO2CF3)n(CN)3−n (n = 1,2) were synthesized. The solid‐state structure of cesium cyanobis(trifluoromethylsulfonyl)methanide was determined by single‐crystal X‐ray diffraction. Phenyldiazonium cyanobis(triluoromethylsulfonyl)methanide underwent decomposition to yield theoxo‐sulfonium ylide—trifluoromethyl(phenoxy)oxosulfonium cyano(trifluoromethylsulfonyl)methanide. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 565–570, 1998

Attaby, Fawzy A.; Eldin, Sanaa M.; Elneairy, M. A. A.

doi: 10.1002/(SICI)1098-1071(1998)9:6<571::AID-HC8>3.0.CO;2-7pmid: N/A

Several pyrido[2,1‐b]thiazines and thiazolo[2,3‐a]pyridines were synthesized by reactions of cinnamonitriles with appropriate halocarbonyl compounds. Hydrazones of 3‐diazotized aminopyrazolo[3,4‐b]pyridinones were synthesized by coupling of their corresponding diazonium salts with several active methylene reagents. The obtained hydrazones were cyclized in refluxing ethanol containing a catalytic amount of triethylamine to afford the corresponding pyrazolopyridotriazines. All structures were established by considering the data of elemental analyses, IR, 1H‐NMR, and mass spectra. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 571–579, 1998

Ogawa, Akiya; Takami, Noriaki; Sekiguchi, Masahito; Sonoda, Noboru; Hirao, Toshikazu

doi: 10.1002/(SICI)1098-1071(1998)9:6<581::AID-HC9>3.0.CO;2-7pmid: N/A

Elemental sulfur can be reduced to the corresponding thiolate anion species (S2− and S2−2) selectively by samarium diiodide in the presence and absence of HMPA, respectively. The subsequent alkylation of the thiolate anion species provides a useful synthetic route to dialkyl sulfides and disulfides. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 581–584, 1998

Zhou, Jia; Chen, Ruyu

doi: 10.1002/(SICI)1098-1071(1998)9:6<585::AID-HC10>3.0.CO;2-Npmid: N/A

A desulfurization reaction of the title compounds, as cyclic substrates, utilizing an Ag+−H2O or ROH system, is described in this article. The diastereoisomerism of ring‐opening products and the possible reaction mechanism are also discussed. Themolecular structure of α‐(3‐phenylureido)‐α‐(2,4‐dichlorophenyl)methylphenylphosphinic acid (4a) was determined by X‐ray diffraction. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 585–590, 1998