DMAP‐Catalyzed [3+3] Annulation of Cyclopropenones with α‐Bromoketones for Synthesis of 2‐Pyrones. Issue 15 (13th April 2022)

• Record Type: Journal Article
• Authors: Qiao, Lijuan; He, Xin; Yang, Lulu; Raveendra Babu, Kaki; Wu, Yong; Tang, Yuhai; Xu, Silong
• Is Part Of: European journal of organic chemistry. Volume 2022:Issue 15(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-13
• Subjects: Annulation -- Cyclopropenone -- Halides -- Organocatalysis -- Synthetic methods; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202200243
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: DMAP‐catalyzed [3+3] annulation of cyclopropenones with α‐bromoketones is described, which provides a simple and convenient synthesis of 2‐pyrones in good yields with a broad scope. The reaction features advantages of transition metal‐free conditions, readily available starting materials, and excellent regioselectivity. Experimental investigation and DFT calculations suggest a mechanism encompassing pyridium ylide‐initiated ring opening of cyclopropenones, elimination of DMAP catalyst, and final 6π‐electrocyclization. Abstract : The DMAP‐catalyzed [3+3] annulation of cyclopropenones with α‐bromoketones was developed for a convenient synthesis of 2‐pyrones. The mechanism may proceed in a pyridium ylide‐initiated ring opening of cyclopropenones, followed by elimination of DMAP catalyst, and final 6π‐electrocyclization.