title: Highly Regioselective Palladium-Catalyzed Carboxylation of Allylic Alcohols with CO2.
abstract: Various allylic alcohols were carboxylated in the presence of a catalytic amount of PdCl2 and PPh3 using ZnEt2 as a stoichiometric transmetalation agent under a CO2 atmosphere (1 atm). This carboxylation proceeded in a highly regioselective manner to afford branched carboxylic acids predominantly. The β,γ-unsaturated carboxylic acid thus obtained was successfully converted into an optically active γ-butyrolactone, a known intermediate of (R)-baclofen.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Nishi 6, Kita 12, Kita-ku, Sapporo 060-0812 (Japan), Fax: (+81) 11-706-3722 http://gouka.pharm.hokudai.ac.jp/FSC/jpn/page/top_page.htm. tmita@pharm.hokudai.ac.jp.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Mita
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Nishi 6, Kita 12, Kita-ku, Sapporo 060-0812 (Japan), Fax: (+81) 11-706-3722 http://gouka.pharm.hokudai.ac.jp/FSC/jpn/page/top_page.htm.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Higuchi
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Nishi 6, Kita 12, Kita-ku, Sapporo 060-0812 (Japan), Fax: (+81) 11-706-3722 http://gouka.pharm.hokudai.ac.jp/FSC/jpn/page/top_page.htm. biyo@pharm.hokudai.ac.jp.|ACT-C, Japan Science and Technology Agency (JST), Sapporo 060-0812 (Japan). biyo@pharm.hokudai.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
keywords: allylic compounds; carbon dioxide; carboxylation; carboxylic acids; umpolung