Nucleophilic‐Bisphosphine‐Catalysed One‐Pot Sequential [4+2]/[4+2] Annulation of an Allenoate with Benzylidenepyrazolones. Issue 21 (10th June 2015)

• Record Type: Journal Article
• Authors: Jia, Yu; Tang, Xiao; Cai, Guowei; Jia, Ruxuan; Wang, Boran; Miao, Zhiwei
• Is Part Of: European journal of organic chemistry. Issue 21(2015)
• Page Start: 4720
• Page End: 4725
• Publication Date: 2015-06-10
• Subjects: Synthetic methods -- Annulation -- Spiro compounds -- Nitrogen ­heterocycles; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201500399
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: An efficient bisphosphine‐catalysed sequential [4+2]/[4+2] annulation reaction of a γ‐benzyl allenoate with benzylidenepyrazolones has been developed. Under the catalysis of DPPB [1, 3‐bis(diphenylphosphanyl)butane], the [4+2]/[4+2] annulation proceeded smoothly to give spiro‐pyrazolidinone derivatives in moderate yields. This protocol provides a simple and practical strategy for the construction of highly substituted 2 H ‐spiro[naphthalene‐pyrazole] skeletons. Abstract : Spiro‐pyrazolidinones have been synthesized through a bisphosphine‐triggered sequential [4+2]/[4+2] annulation reaction of 4‐benzylidene‐5‐methyl‐2‐phenyl‐2, 4‐dihydropyrazolone with a γ‐benzyl‐substituted allenoate in moderate yields.