立体选择性和对映选择性逆电子需求 Diels-Alder 环加成反应 between 2-吡喃酮和非环状烯醇醚。

Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 15, rue Georges Clémenceau, 91405, Orsay Cedex, France.

Institute of Organic Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria.

Angew Chem Int Ed Engl. 2022 Oct 17;61(42):e202208185. doi: 10.1002/anie.202208185. Epub 2022 Sep 14.

A broadly applicable diastereo- and enantioselective inverse-electron-demand Diels-Alder reaction of 2-pyrones and acyclic enol ethers is reported herein. Using a copper(II)-BOX catalytic system, bridged bicyclic lactones are obtained in very high yields (up to 99 % yield) and enantioselectivities (up to 99 % ee) from diversely substituted 2-pyrones and acyclic enol ethers. Mechanistic experiments as well as DFT calculations indicate the occurrence of a stepwise mechanism. The synthetic potential of the bridged bicyclic lactones is showcased by the enantioselective synthesis of polyfunctional cyclohexenes and cyclohexadienes, as well as a carbasugar unit.

本文报道了一种广泛适用的非对映和对映选择性逆电子需求 Diels-Alder 反应，涉及 2-吡喃酮和无环烯醇醚。使用铜（II）-BOX 催化体系，从各种取代的 2-吡喃酮和无环烯醇醚中，可以非常高的收率（高达 99%）和对映选择性（高达 99%ee）获得桥环双环内酯。机理实验和密度泛函理论（DFT）计算表明该反应经历了分步反应机制。桥环双环内酯的合成潜力通过对多功能环己烯和环己二烯以及碳杂糖单元的对映选择性合成得到了展示。