Carbocation catalyzed carboxylic acid activation in Staudinger reaction for stereoselective synthesis of β-lactams. Issue 46 (16th November 2016)

• Record Type: Journal Article
• Authors: Rai, Ankita; Singh, Puneet K.; Shukla, Prashant; Rai, Vijai K.
• Is Part Of: Tetrahedron letters. Volume 57:Issue 46(2016)
• Page Start: 5084
• Page End: 5088
• Publication Date: 2016-11-16
• Subjects: Cyclopropenone -- Carbocation activation -- β-Lactam -- Carboxylic acids -- Aldimines; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2016.10.012
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Catalytic behavior of the cyclopropenium-carbocation has been explored. Synthesis of β-lactams via cyclopropenium-ion-catalyzed reaction of substituted acetic acids with aldimines. High yields (86–95%) and good diastereoselectivity are reported. Operational simplicity, ambient reaction conditions, use of carboxylic acids for β-lactam synthesis. Cyclopropenone is regenerated easily during the reaction for further use without any loss of efficiency. Abstract: A novel strategy to synthesize stereoselective β-lactams has been disclosed via cyclopropenium-ion-catalyzed reaction of substituted acetic acids with aldimines under mild conditions. Products are formed in high yields (86–95%) and good diastereoselectivity within 3–4 h. The new reaction is focused on the exploration of the scope of cyclopropenium-ion catalysis and introduction of a catalytic version of one-step Staudinger reaction for β-lactam synthesis. The reaction is effective for a range of substituted acetic acids and aldimines.