Site-Selective Catalysis of Phenyl Thionoformate Transfer as a Tool for Regioselective Deoxygenation of Polyols

详细信息    查看全文

• 作者：Marí ; a S&aacute ; nchez-Roselló ; Angela L. A. Puchlopek ; Adam J. Morgan ; Scott J. Miller
• 刊名：Journal of Organic Chemistry
• 出版年：2008
• 出版时间：March 7, 2008
• 年：2008
• 卷：73
• 期：5
• 页码：1774 - 1782
• 全文大小：326K
• 年卷期：v.73,no.5(March 7, 2008)
• ISSN：1520-6904

文摘

jo702334zn00001>

journals/joceah/73/i05/figures/jo702334zn00001.gif" ALIGN="left" HSPACE=5>

We report the application of peptide-embedded imidazoles as catalysts for the site-selective delivery ofthe phenyl thionoformate unit as a prelude to deoxygenation reactions of polyols. Methodology wasdeveloped that allows for the synthesis of thiocarbonyl derivatives based on a combination of additivesthat include N-alkylimidazoles and FeCl₃ as co-catalysts. The use of this reagent combination leads toincreased reaction rates and efficient yields relative to those of simple base-mediated reactions. In termsof controlling regioselectivity during the course of polyol modification, we found that histidine-containingpeptides, in combination with FeCl₃, could lead to modulation of the product distribution. Throughscreening of peptides and control of reaction conditions, products could be observed that reflected boththe inherent preference of substrates and also reversal of inherent selectivity.