10.1002/anie.201301426
The key substrate used in this study, N-methoxybenzamide (1a), is an amide with a methoxy group attached to the nitrogen atom. It is key for the initial reaction with a,b-unsaturated aldehydes and ketones. Another amide substrate used in this study, N-methylbenzamide (1b), has a methyl group attached to the nitrogen atom, which affects the reactivity and selectivity of the C-H activation process. N-n-butylbenzamide (1c), an amide with a butyl group attached to the nitrogen atom, demonstrates the versatility of the method towards different alkyl groups. N-benzylbenzamide (1d), an amide with a benzyl group attached to the nitrogen atom, is used to demonstrate the tolerance of the reaction towards aromatic groups. Acrolein (2a), the simplest unsaturated aldehyde used in this study, acts as the electrophilic component in the cyclization process and reacts with the amide to generate the desired azacyclopentane product.