Multicomponent One-Pot Synthesis of Aminals and Thioaminals

Significance

This one-pot multi-component reaction offers a convenient and fast access to ‘oxidized’ amides, including acyl aminals and acyl thioaminals. If nitriles with an ether group at the α-carbon are employed, the formation of the respective aminal is observed to proceed with some diastereoselection. Hereby, the reaction may pass through two different pathways, one involving addition via chelation leading to the anti isomer and the other via an attack in accordance with the Felkin-Anh model leading to the syn isomer. The dia­stereoselectivity can be increased in favor of the syn products when non-chelating thiols are used, whereas the application of phenol increases the diastereoselectivity in favor of the anti products.