title: Pd0-mediated rapid cross-coupling reactions, the rapid C-[11C]methylations, revolutionarily advancing the syntheses of short-lived PET molecular probes.
abstract: Positron emission tomography is a noninvasive method for monitoring drug (or diagnostic) behavior and its localization on the target molecules in the living systems, including the human body, using a short-lived positron-emitting radionuclide. New methodologies for introducing representative short-lived radionuclides, (11)C and (18)F, into the carbon frameworks of biologically active organic compounds have been established by developing rapid C-[(11)C]methylations and C-[(18)F]fluoromethylations using rapid Pd(0)-mediated cross-coupling reactions between [(11)C]methyl iodide (sp(3)-hybridized carbon) and an excess amount of organotributylstannane or organoboronic acid ester having sp(2) (phenyl, heteroaromatic, or alkenyl), sp(alkynyl), or sp(3) (benzyl and cinnamyl)-hybridized carbons; and [(18)F]fluoromethyl halide (iodide or bromide) and an organoboronic acid ester, respectively. These rapid reactions provide a firm foundation for an efficient and general synthesis of short-lived (11)C- or (18)F-labeled PET molecular probes to promote in vivo molecular imaging studies.
authors.affiliation: National Center for Geriatrics and Gerontology, 35 Gengo Morioka-cho, Obu-shi, Aichi, 474-8511, Japan. suzukims@ncgg.go.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Hisashi
authors.initials: H
authors.lastname: Doi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Koyama
authors.forename: Zhouen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Hosoya
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Onoe
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis; D002250:Carbon Radioisotopes / Q000737:chemistry; D002384:Catalysis; D006801:Humans; D006847:Hydrocarbons, Iodinated / Q000737:chemistry; D007553:Isotope Labeling; D008745:Methylation; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D006847:Hydrocarbons, Iodinated; D015335:Molecular Probes; D019275:Radiopharmaceuticals; D010165:Palladium; C014055:methyl iodide
keywords: C-[11C]methylation; cross-coupling; imaging agents; positron emission tomography; radiopharmaceuticals