The first enantioselective organocatalytic α-allylation of cyclic ketones has been accomplished via singly occupied molecular orbital catalysis. Geometrically constrained radical cations, forged from the one-electron oxidation of transiently generated enamines, readily undergo allylic alkylation with a variety of commercially available allyl silanes. A reasonable latitude in both the ketone and allyl silane components is readily accommodated in this new transformation. Moreover, three new oxidatively stable imidazolidinone catalysts have been developed that allow cyclic ketones to successfully participate in this transformation. The new catalyst platform has also been exploited in the first catalytic enantioselective α-enolation and α-carbooxidation of ketones.
通过单占据分子轨道催化,已经实现了环状酮的第一个对映选择性有机催化α-烯丙基化反应。由暂时生成的烯胺一电子氧化而形成的几何约束的自由基阳离子,能够与多种商业可获得的烯丙基硅烷发生烯丙基烷基化反应。在这种新的转化中,环状酮和烯丙基硅烷组分都有相当大的宽容度。此外,已经开发了三种新的氧化稳定的咪唑啉酮催化剂,使环状酮能够成功参与这一转化。这种新的催化剂平台还被用于酮的首个催化对映选择性α-烯酰基化和α-碳氧化反应。