Subscribe to RSS
DOI: 10.1055/s-0028-1088099
Intramolecular Friedel-Crafts-Type α-Arylation of Aldehydes
Contributor(s):Benjamin List, Ilija ČorićThe Scripps Research Institute, La Jolla and University of California, San Diego, USA; , Universität Karlsruhe, Germany
Enantioselective Intramolecular Friedel-Crafts-Type α-Arylation of Aldehydes
J. Am. Chem. Soc. 2009, 131: 2086-2087
Publication History
Publication Date:
23 March 2009 (online)
Key words
SOMO catalysis - α-arylation - aldehydes
Significance
Intramolecular Friedel-Crafts-type α-arylation of aldehydes under SOMO catalysis has been reported. Using the secondary amine catalyst 1 and CAN as the oxidant, aldehydes 2 were obtained in good yields and with high enantioselectivity. An application of the method was demonstrated by the total synthesis of the antitumor natural product demethyl calamenene.
Comment
Organocatalytic enantioselective α-arylation of aldehydes was first reported by the Jørgensen group (Angew. Chem. Int. Ed. 2007, 46, 5520) employing the addition of aldehydes to quinones. Nicolaou and co-workers applied the organo-SOMO methodology introduced by the Sibi group (J. Am. Chem. Soc. 2007, 129, 4124) and the MacMillan group (Science 2007, 316, 582). In this reaction the electron-rich aromatic system serves as the SOMOphile for the radical cation moiety in A resulting in the σ-complex B, a characteristic intermediate in typical Friedel-Crafts reactions.