Oxidative synthesis of cyclic acyl aminals through carbon-carbon sigma-bond activation.

Acyliminium ions can be prepared through photoinitiated single-electron oxidation reactions of homobenzylic amides and carbamates. Cyclic acyl aminals are formed when these acyliminium ions are appended to nucleophiles such as hydroxyl, ether, and sulfonamide groups. The scope of these reactions is discussed along with mechanistic issues relating to the energetics, chemoselectivity, and stereoelectronic effects of bond activation. [reaction: see text]