Chelate-controlled carbonyl addition reactions. The exceptional chelating abilityof dimethylaluminum chloride and methylaluminum dichloride

✍ Scribed by David A. Evans; Brett D. Allison; Michael G. Yang

• Book ID: 104261522
• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 294 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(99)00739-x

✦ Synopsis

Highly selective cheladon-controlled aldol and allyi nucleophile additions to 13-alkoxy aldehydes promoted by dimethylaluminum chloride and methylaluminum dichloride are described. Cationic aluminum chelates are proposed as intermediates in these reactions. Evidence is provided to support the claim that chelate organization with Me2AICI and MeA1C! 2 is possible even with ~-tert-butyldimethyl-silyloxy groups. Stereoselectivity data comparing the chelating potential of Me2AICI, MeAICI2, SnCI 4, and TiCI 4 is provided.