Synthesis and Structure of m-Terphenyl Thio-, Seleno-, and Telluroethers

• Published in: Journal of organic chemistry Vol. 75; no. 24; pp. 8363 - 8371
• Main Authors: Zakai, Uzma I, Błoch-Mechkour, Anna, Jacobsen, Neil E, Abrell, Leif, Lin, Guangxin, Nichol, Gary S, Bally, Thomas, Glass, Richard S
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 17.12.2010; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; Noncondensed benzenic compounds; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; METAL DERIVATIVES; ALKALI-METAL; DENSITY-FUNCTIONAL METHODS; CHEMICAL-SHIFTS; MOLYBDENUM; ARYL HALIDES; COMPLEXES; LIGAND; CSOH-CENTER-DOT-H2O; MOLECULES; Water; Organic selenide; Molecular structure; Organic ditelluride; NMR spectrometry; Energy barrier; Organic sulfide; Tellurium; Characterization; Organic iodine compounds; Methyl sulfoxide; Aromatic compound; Selenium; Chemical synthesis; Electrophile; Terphenyl derivatives; Interconversion; Organic telluride; Chalcogen; Isomerization; Theoretical study; X ray diffraction; Grignard reagent; Atropoisomerism; Benzenic compound; Cesium Hydroxides; Crystalline structure
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo101299x

Several routes for the synthesis of m-terphenyl thio-, seleno-, and telluroethers were investigated. m-Terphenyl iodides react with diphenyl diselenides or ditellurides (CsOH·H2O, DMSO, 110 °C) to give the desired compounds in 19−84% yield which significantly extends the previously reported such reactions because o-benzyne cannot be an intermediate as previously suggested. However, the most general synthetic route was that involving reaction of 2,6-diaryl Grignard reagents with sulfur, selenium, or tellurium electrophiles. The m-terphenyl thio-, seleno-, and telluroethers were characterized spectroscopically and, in one case, by single-crystal X-ray analysis. Certain of these compounds showed atropisomerism and barriers for interconversion of isomers were determined by variable-temperature NMR spectroscopy. The barriers for interconverting the syn and anti atropisomers increase on going from the analogous S to Se to Te compounds. Calculations on this isomerization revealed that the barriers are due to rotation about the aryl−aryl bond and that the barriers for rotation about the aryl−chalcogen bond are much lower.