3-Zinciobenzofuran and 3-Zincioindole: Versatile Tools for the Construction of Conjugated Structures Containing Multiple Benzoheterole Units

Autor: Eiichi Nakamura, Saika Otsubo, Laurean Ilies, Masaharu Nakamura
Rok vydání: 2006
Předmět:
Zdroj: ChemInform. 37
ISSN: 1522-2667
0931-7597
DOI: 10.1002/chin.200623097
Popis: General. All the reactions dealing with air or moisture sensitive compounds were carried out in a dry reaction vessel under a positive pressure of argon or nitrogen. Airand moisture-sensitive liquids and solutions were transferred via syringe or stainless steel cannula. Analytical thin-layer chromatography was performed using glass plates pre-coated with 0.25-mm 230‐400 mesh silica gel impregnated with a fluorescent indicator (254 nm). Thin layer chromatography plates were visualized by exposure to ultraviolet light (UV) and/or by immersion in an acidic staining solution of p-anisaldehyde followed by heating on a hot plate. Organic solutions were concentrated by rotary evaporation at ca. 15 Torr (evacuated with a diaphragm pump). Flash column chromatography was performed as described by Still et al., 1 employing Kanto Silica gel 60 (spherical, neutral, 140‐325 mesh). Materials. Commercial reagents were purchased from Tokyo Kasei Co., Aldrich Inc., and other commercial suppliers and were used either distilled or recrystallized before use. Zinc chloride (anhydrous, beads, -10 mesh, 99.99 %) was purchased from Aldrich and was flame-dried just before use. Anhydrous tetrahydrofuran (THF) and diethylether were purchased from Kanto Chemical Co. and distilled from sodium / benzophenone ketyl at 760 Torr under an argon atmosphere immediately before use. TMEDA and toluene were distilled from calcium hydride at 760 Torr under an argon atmosphere immediately before use. Triethylamine was distilled from calcium hydride at 760 Torr under an argon atmosphere and was subsequently stored over 4-A molecular sieves in a storage flask. The water content of the solvent was confirmed with a Karl-Fischer moisture titrator to be less than 20 ppm. The following starting materials were prepared as described in the literature: 2-phenylethynylphenol, 2 2-(1-hexynyl)phenol, 2
Databáze: OpenAIRE
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