Zotov Vladimir V, Zupancic Carl, Bailey Zachary J, Du Guodong
Department of Chemistry, University of North Dakota, 151 Cornell Street Stop 9024, Grand Forks, North Dakota 58202, United States.
J Org Chem. 2024 Nov 1;89(21):15436-15446. doi: 10.1021/acs.joc.4c01179. Epub 2024 Oct 18.
Hydrosilanes are widely used as reducing agents in the reduction of carbonyl groups, and various catalysts have been developed for the activation of hydrosilanes, the majority of them being transition metal-based. A main-group-based Lewis acid tris(pentafluorophenyl)borane (BCF) has gained increasing attention due to its Lewis acidity and versatility, along with being nonmetal. Herein, we describe the BCF-catalyzed ring opening reduction of cyclic anhydrides using hydrosilanes as a source of hydrides. The reduction affords unsymmetrical bis(silyl) protected hydroxy acids, leading to an efficient way for the synthesis of silyl ester functionalities. The capability of forming protected hydroxy acids under mild conditions with high yields in one step is also advantageous. A range of hydrosilanes and cyclic anhydrides can be employed with quantitative conversion, high yields, relatively fast reaction time, and mild reaction conditions. NMR spectroscopy is used in the characterization of the products, along with gaining insight into the potential mechanism.
硅烷广泛用作羰基还原反应中的还原剂，人们已开发出各种用于活化硅烷的催化剂，其中大多数是过渡金属基催化剂。一种主族路易斯酸三（五氟苯基）硼烷（BCF）因其路易斯酸性、多功能性以及非金属特性而受到越来越多的关注。在此，我们描述了以硅烷作为氢化物来源，由BCF催化的环状酸酐的开环还原反应。该还原反应可得到不对称双（硅基）保护的羟基酸，为合成硅基酯官能团提供了一种有效方法。在温和条件下一步高产率地形成保护羟基酸的能力也具有优势。一系列硅烷和环状酸酐可用于该反应，反应具有定量转化、高产率、相对较快的反应时间以及温和的反应条件。核磁共振光谱用于产物的表征，同时有助于深入了解潜在的反应机理。
