Camphor-derived thioureas: Synthesis and application in asymmetric Kabachnik-Fields reaction

A series of camphor-derived thiourea organocatalysts 3a–f were designed and synthesized from (1R,3S)-camphoric acid 1 and applied to the one-pot three-component Kabachnik–Fields reaction. Catalyst 3c was found to be an efficient organocatalyst for the reaction of 2-cyclopropylpyrimidin-4-carbaldehyde 4, various amines 5, and diphenylphosphite 6 to yield the corresponding enantioselective α-aminophosphonates 7a–e in 74%–82% yields and 14%–35% ee.

Graphical abstractA series of enantiopure camphor-derived thioureas were synthesized and used as organocatalysts in the one pot three-component asymmetric Kabachnik–Fields reaction leading to enantioselective α-aminophosphonates.Figure optionsDownload full-size imageDownload as PowerPoint slide