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Lewis Super‐Acid Catalyzed Cyclizations: A New Route to Fragrance Compounds
Author(s) -
Coulombel Lydie,
Grau Fanny,
Weïwer Michel,
Favier Isabelle,
Chaminade Xavier,
Heumann Andreas,
Bayón J. Carles,
Aguirre Pedro A.,
Duñach Elisabet
Publication year - 2008
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.200890086
Subject(s) - chemistry , cycloisomerization , catalysis , lewis acids and bases , organic chemistry , substituent , heteroatom , ligand (biochemistry) , medicinal chemistry , alkyl , biochemistry , receptor
This review deals with the application of Lewis super acids such as Al III , In III , and Sn IV triflates and triflimidates as catalysts in the synthesis of fragrance materials. Novel catalytic reactions involving CC and Cheteroatom bond‐forming reactions, as well as cycloisomerization processes are presented. In particular, Sn IV and Al III triflates were employed as catalysts in the selective cyclization of unsaturated alcohols to cyclic ethers, as well as in the cyclization of unsaturated carboxylic acids to lactones. The addition of thiols and thioacids to non‐activated olefins, both in intra‐ and intermolecular versions, was efficiently catalyzed by In III derivatives. Sn IV Triflimidates catalyzed the cycloisomerization of highly substituted 1,6‐dienes to gem‐dimethyl‐substituted cyclohexanes bearing an isopropylidene substituent. The hydroformylation of these unsaturated substrates, catalyzed by a Rh I complex with a bulky phosphite ligand, selectively afforded the corresponding linear aldehydes. The olfactory evaluation of selected heterocycles, carbocycles, and aldehydes synthesized is also discussed.