Ni-Catalyzed Sonogashira Coupling of Nonactivated Alkyl Halides: Orthogonal Functionalization of Alkyl Iodides, Bromides, and Chlorides
作者:Oleg Vechorkin、Delphine Barmaz、Valérie Proust、Xile Hu
DOI:10.1021/ja906040t
日期:2009.9.2
Ni-catalyzed Sonogashira coupling of nonactivated, beta-H-containing alkyl halides, including chlorides, is reported. The coupling is tolerant to a wide range of functional groups, including ether, ester, amide, nitrile, keto, heterocycle, acetal, and aryl halide, in both coupling partners. The coupling can be selective for a specific C-X bond (X = I, Br, Cl) and allows for orthogonal functionalization
Chemoselective Aerobic Cross-Dehydrogenative Coupling of Terminal Alkynes with Hydrosilanes by a Nanoporous Gold Catalyst
作者:Rahul D. Kavthe、Yoshifumi Ishikawa、Indra Kusuma、Naoki Asao
DOI:10.1002/chem.201803874
日期:2018.10.22
Aerobic cross‐dehydrogenative coupling between terminal alkynes and hydrosilanes occurred in the presence of nanoporous gold catalyst under O2 atmosphere. A variety of alkynylsilanes were synthesized in good‐to‐high yields and the catalyst was easily recovered and reused many times. Furthermore, the chemoselective direct silyl protection of terminalacetylenes of alkynols over the hydroxyl groups was
Construction of Methylenecycloheptane Frameworks through 7<i>-Exo-Dig</i> Cyclization of Acetylenic Silyl Enol Ethers Catalyzed by Triethynylphosphine−Gold Complex
作者:Hideto Ito、Hirohisa Ohmiya、Masaya Sawamura
DOI:10.1021/ol101860j
日期:2010.10.1
A cationic gold(I) complex bearing a semihollow-shaped triethynylphosphine ligand efficiently catalyzed the 7-exo-dig cyclization of silylenolethers with an ω-alkynic substituent. The reaction gave various methylenecycloheptane derivatives with an exo- or endocyclic carbonyl group. The protocol was applicable not only to cyclic substrates that form bicyclic frameworks but also to acyclic ones with
Aiming to image NTS1 overexpressing tumors, the diarylpyrazole glycoconjugate 8, derived from the potent NTS1 antagonist SR142948A, was synthesized taking advantage of the palladium-catalyzed aminocarbonylation reaction. The glycoconjugate 8 displayed excellent affinity and selectivity toward NTS1. Radiosynthesis proceeded straightforwardly, obtaining [F-18]8 with excellent stability and highly beneficial biodistribution in vivo as demonstrated by PET imaging in HT29 tumor-bearing nude mice. Thus, the tracer [F-18]8 represents a highly promising candidate for PET imaging of NTS1-positive tumors.