title: Efficient and convenient heterogeneous palladium-catalyzed regioselective deuteration at the benzylic position.
abstract: The Pd/C-catalyzed efficient and regioselective hydrogen-deuterium (H-D) exchange reaction on the benzylic site proceeded in D2O in the presence of a small amount of H2 gas. The use of the Pd/C-ethylenediamine complex [Pd/C(en)] as a catalyst instead of Pd/C led to the efficient deuterium incorporation into the benzylic site of O-benzyl protective groups without hydrogenolysis. These H-D exchange reactions provide a post synthetic and D(2)-gas-free deuterium-labeling method on a wide variety of benzylic sites using D2O as the deuterium source and heterogeneous Pd/C or Pd/C(en) as a reusable heterogeneous palladium catalyst under mild and neutral conditions.
authors.affiliation: Laboratory of Medicinal Chemistry, Gifu Pharmaceutical University, Mitahora-higashi 5-6-1, Gifu 502-8585, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kurita
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hattori
authors.forename: Saori
authors.initials: S
authors.lastname: Seki
authors.forename: Takuto
authors.initials: T
authors.lastname: Mizumoto
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Aoki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamada
authors.forename: Kanoko
authors.initials: K
authors.lastname: Ikawa
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Maegawa
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Monguchi
authors.forename: Hironao
authors.initials: H
authors.lastname: Sajiki
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D003903:Deuterium / Q000737:chemistry; D017666:Deuterium Oxide / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001555:Benzene Derivatives; D005029:Ethylenediamines; D012997:Solvents; D010165:Palladium; C031234:ethylenediamine; D002244:Carbon; D006859:Hydrogen; D003903:Deuterium; D017666:Deuterium Oxide