Stereoselective Synthesis of CF3-Containing Tetrasubstituted Oxiranes and Ethenes.
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Accession number;02A0620412
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| Title;Stereoselective Synthesis of CF3-Containing Tetrasubstituted Oxiranes and Ethenes. |
| Author;
FUJIMOTO TAKUYA
(Kyoto Univ., Graduate School, JPN)
MINEZAKI HIROSHI
(Kyoto Univ., Graduate School, JPN)
HATA TAKESHI
(Kyoto Univ., Graduate School, JPN)
SHIMIZU MASAKI
(Kyoto Univ., Graduate School, JPN)
HIYAMA TAMEJIRO
(Kyoto Univ., Graduate School, JPN)
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Journal Title;Fusso Kagaku Toronkai Koen Yoshishu
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Journal Code:F0135B
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ISSN:
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VOL.25th;NO.;PAGE.33-35(2001)
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| Figure&Table&Reference; |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Much attention is paid on trifluoromethylated agrochemicals, pharmaceuticals, and materials because incorporation of a trifluoromethyl group into target molecules often leads to dramatic changes of physical, chemical, and biological properties of the parent agents. In view of the unique reactivities of fluorine-containing substrates, novel synthetic methods for the highly effective preparation of stereodefined CF3-containing compounds are the key for exploration of novel materials and biological agents, We found that treatment of 2-substituted 3,3-dichloro-1,1,1-trifluoropropan-2-ol with 3 molar amounts of organolithium reagent R2Li in THF at -98.DEG.C. generated stereoselectively R2-containing oxiranyllithium with Li and CF3 group being arranged cis. The formation of oxiranyllithium via .BETA.-oxido carbenoid sharply contrasts with the reaction of non-fluorinated .BETA.-oxido carbenoids that usually undergo rearrangement reaction to produce .ALPHA.-chloro carbonyl compounds. Quenching oxiranyllithium with methanol, chlorosilane, alkyl halide, aldehyde, or ketone afforded the corresponding CF3-containing tri- or tetrasubstituted oxiranes stereoselectively. Furthermore, reaction of with organoboron reagent was found to give CF3-containing tetrasubstituted ethenes stereoselectively. Aryl, alkenyl, alkynyl, alkyl, and boryl boranes are available. (author abst.) |
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