title: Chiral silver phosphate catalyzed transformation of ortho-alkynylaryl ketones into 1H-isochromene derivatives through an intramolecular-cyclization/enantioselective-reduction sequence.
abstract: The transformation of ortho-alkynylaryl ketones through a cyclization/enantioselective-reduction sequence in the presence of a chiral silver phosphate catalyst afforded 1H-isochromene derivatives in high yield with fairly good to high enantioselectivity. An asymmetric synthesis of the 9-oxabicyclo[3.3.1]nona-2,6-diene framework, which has been found in some biologically active molecules, is presented as a demonstration of the synthetic utility of this method.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan) http://www.orgreact.sakura.ne.jp/index.html; Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan). mterada@m.tohoku.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Terada
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Toda
keywords: asymmetric catalysis; cyclization; enantioselective reduction; isobenzopyrylium ions; silver salts