Enantioselective Fluorination Mediated by Cinchona Alkaloid Derivatives/Selectfluor Combinations: Reaction Scope and Structural Information for N-Fluorocinchona Alkaloids

来自 NCBI

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作者：

Norio，Shibata，Emiko，Suzuki，Toru，Asahi，Motoo，Shiro

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摘要：

Cinchona-alkaloid/Selectfluor combinations efficiently fluorinate a variety of carbonyl compounds in a highly enantioselective manner to furnish chiral α-fluorocarbonyl compounds. The DHQB/Selectfluor combination is effective for the enantioselective fluorination of indanones and tetralones 1 in up to 91% ee. The first enantioselective syntheses of chiral derivatizing reagents 3 was accomplished with high ee and in high chemical yields by the DHQDA/Selectfluor combination. 3-Fluorooxindoles 7 were prepared with ee up to 83% using the (DHQ)2AQN/Selectfluor or the (DHQD)2PYR/Selectfluor combination. Since the combinations are conveniently prepared in situ from readily available reagents, the present system represents a practical method for enantioselective fluorination. X-ray crystallography and 1H NMR analyses of the cinchona alkaloids/Selectfluor combination have established that the species that mediate this novel reaction are N-fluoroammonium cinchona alkaloid tetrafluoroborates, which adopt open conformations.

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关键词：

diastereoselective syntheses, enantioselective syntheses (incl. ci/trans‐isomerism halogenation indan derivatives benzofuran derivatives indole derivatives, isoindole derivatives carboxylic acid derivatives (naphthalene compounds

DOI：

10.1021/ja010789t

被引量：

620

年份：

2001