Synthesis 2005(5): 791-797  
DOI: 10.1055/s-2005-861813
PAPER
© Georg Thieme Verlag Stuttgart · New York

Heterosubstituted or Functionalized Derivatives of 1- and 2-(Trifluoro­methyl)naphthalenes Emanating from Aryne Adducts

Frédéric Bailly, Fabrice Cottet, Manfred Schlosser*
Institut des Sciences Chimiques (ISIC-BCh), Ecole Polytechnique Fédérale, 1015 Lausanne, Switzerland
e-Mail: manfred.schlosser@epfl.ch;
Further Information

Publication History

Received 13 October 2004
Publication Date:
09 February 2005 (online)

Abstract

More than two dozen new CF3-substituted naphthalene derivatives were prepared in an expedient way by employing 3- and 4-(trifluoromethyl)benzyne as the key intermediates. 2- and 4-Chlorobenzotrifluoride were treated with butyllithium and the organometallic species thus generated were allowed to decompose in the presence of furan. The resulting cycloadducts 1 and 14 were reduced to the (trifluoromethyl)naphthalenes 2 and 15, ring-opened to the (trifluoromethyl)naphthols 3, 16 and 17 and transformed to the dibromo adducts 5 and 18. The latter were stereoselectively converted into the bromo-1,4-epoxy-1,4-dihydro(trifluoromethyl)naphthalenes 6, 7, 19 and 20 and, by deoxygenation, into various bromo(trifluoromethyl)naphthalenes 8, 9, 21 and 22. Trifluoro­methyl substituted naphthoic acids 10-13 and 23-26 were obtained when the bromo compounds 6-9 and 19-22 were subjected to a halogen/metal permutation followed by carboxylation.