Rhodium‐Catalyzed Spirocyclization of Maleimide with N‐Aryl‐2, 3‐dihydrophthalazine‐1, 4‐dione to Access Pentacyclic Spiro‐Succinimides. Issue 10 (31st August 2021)

• Record Type: Journal Article
• Authors: Karishma, Pidiyara; Mandal, Sanjay K.; Sakhuja, Rajeev
• Is Part Of: Asian journal of organic chemistry. Volume 10:Issue 10(2021)
• Page Start: 2580
• Page End: 2590
• Publication Date: 2021-08-31
• Subjects: C−H Activation -- Cyclization -- Rhodium -- Spiro Compounds -- Catalysis; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; 547.005
• DOI: 10.1002/ajoc.202100384
• Languages: English
• ISSNs: 2193-5807

Abstract

Abstract: A one‐pot spirocyclization of 2‐aryl‐2, 3‐dihydrophthalazine‐1, 4‐diones with maleimides was achieved via Rh III ‐catalyzed sequential ortho ‐alkenylation followed by intramolecular aza‐Michael‐type addition/protonation process. The featured strategy furnishes a series of diversely decorated spiro[indazolo[1, 2‐ b ]phthalazine‐13, 3′‐pyrrolidine]‐2′, 5′, 6, 11‐tetraones in high yields from a variety of 2‐aryl‐2, 3‐dihydrophthalazine‐1, 4‐diones and N ‐aryl/alkyl maleimides, which can be scaled‐up easily. Isolation and characterization of a maleimide‐coordinated five‐membered rhodacyclic intermediate provided a strong evidence for the proposed mechanism of the reaction. Abstract : A Rh III ‐catalyzed strategy for the spirocyclization of 2‐aryl‐2, 3‐dihydrophthalazine‐1, 4‐diones with maleimides is disclosed, via ortho ‐alkenylation followed by intramolecular aza‐Michael‐type addition/protonation process, to afford spiro[indazolo[1, 2‐ b ]phthalazine‐13, 3′‐pyrrolidine]‐2′, 5′, 6, 11‐tetraones in good‐to‐excellent yields.