Langer P. Regio- and diastereoselective cyclization reactions of free and masked 1,3-dicarbonyl dianions with 1,2-dielectrophiles.
Chemistry 2001;
7:3859-66. [PMID:
11596927 DOI:
10.1002/1521-3765(20010917)7:18<3858::aid-chem3858>3.0.co;2-v]
[Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Despite their simplicity and synthetic usefulness, cyclisation reactions of 1,3-dicarbonyl dianions with 1,2-dielectrophiles are problematic, since both dianions and 1,2-dielectrophiles are highly reactive compounds (low reactivity matching). In addition, 1,2-dielectrophiles are often rather labile, and reactions with nucleophiles can result in polymerisation, decomposition, formation of open-chained products, elimination or SET-reactions. These intrinsic limitations can be overcome by a proper reactivity tuning and by the use of electroneutral dianion equivalents (masked dianions) in Lewis acid catalysed reactions. The cyclisations reported herein allow for an efficient, regio- and stereoselective one-pot synthesis of biologically relevant ring systems.
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