Highly selective intermolecular one-pot three component 1,3-dipolar cycloaddition reaction of aldehydes, with phosphonates and proline

The use of L-proline to act as an organocatalyst in the aldol reaction of acylphosphonates and non enolizable aldehydes failed; however, it reacted with the aldehydes to afford azomethine ylides after decarboxylation that in turn underwent 1,3-dipolar cycloaddition with the acylphosphonates to form a bicyclic hexahydropyrrolo[1,2-c]oxazol-1-ylphosphonates in good yield. No azomethine ylide formation was observed on the reaction of acylphosphonates with proline. (C) 2017 Elsevier Ltd. All rights reserved.