Enantioselective Phase-Transfer Catalyzed α-Sulfanylation of Isoxazolidin-5-ones: An Entry to β^2,2-Amino Acid Derivatives

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• 作者：Timothé ; e Cadart ; Dr. Clé ; ment Berthonneau ; Dr. Vincent Levacher ; Dr. Sté ; phane Perrio and Dr. Jean-Fran&ccedil ; ois Briè ; re
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：October 17, 2016
• 年：2016
• 卷：22
• 期：43
• 页码：15261-15264
• 全文大小：1011K
• ISSN：1521-3765

文摘

An unprecedented enantioselective α-functionalization of C4-substituted N-alkoxycarbonyl isoxazolidin-5-ones, readily available platforms from Meldrum's acid derivatives, by N-sulfanylphthalimide (PhthSR) electrophiles was achieved upon an efficient phase-transfer catalytic approach, mediated by a commercial N-spiro quaternary ammonium catalyst. Two catalytic activities of the in situ formed R₄N⁺Phth⁻ species were highlighted, the phtalimidate being involved in the anion metathesis event and likely as a Brønsted base. This sequence offers a straightforward access to α,α-disubstituted isoxazolidinones, which turned out to be useful precursors of α-sulfanyl-β^2,2-amino acid derivatives.