Bifunctional Polyene Cyclizations: Synthetic Studies on Pimarane Natural Products
作者:Julian M. Feilner、Immanuel Plangger、Klaus Wurst、Thomas Magauer
DOI:10.1002/chem.202101926
日期:2021.8.25
Polyenecyclizations generate molecular complexity from a linear polyene in a single step. While methods to initiate these cyclizations have been continuously expanded and improved over the years, the majority of polyene substrates are still limited to simple alkyl-substituted alkenes. In this study, we took advantage of the unique reactivity of higher-functionalized bifunctional alkenes. The realization
[EN] PYCLEN-BASED MACROCYCLIC LIGANDS, CHELATES THEREOF AND USES THEREOF<br/>[FR] LIGANDS MACROCYCLIQUES À BASE DE PYCLEN, LEURS CHÉLATES ET LEURS UTILISATIONS
申请人:CENTRE NAT RECH SCIENT
公开号:WO2019185901A1
公开(公告)日:2019-10-03
The present invention relates to a ligand of Formula (A): or a carboxylate salt thereof; wherein Y1, Y2 and Y3 each independently represents -COOH or a picolinate of Formula (i): wherein each R1 independently represents a chromophore group; L1, L2 and L3 each independently represents a single bond or a linker; and X1, X2 and X3 each independently represents a hydrogen atom, a coupling function or a bio -vectorizing group. The present invention further relates to a process for manufacturing the ligand and to a process for manufacturing a chelate by means of complexation by the ligand of a rare-earth cation, preferably a lanthanide cation. The present invention further relates to the use of the ligand and/or the chelate in biological imaging and/or photoluminescence imaging.
Iridium‐Catalyzed β‐Alkynylation of Aliphatic Oximes as Masked Carbonyl Compounds and Alcohols
作者:Eric Tan、Margherita Zanini、Antonio M. Echavarren
DOI:10.1002/anie.202002948
日期:2020.6.22
An Ir‐catalyzed C(sp3)−H alkynylation of aliphatic ketones, aldehydes, and alcohols was achieved by using the corresponding oxime derivatives and a IrIII catalyst. This general reaction is selective towards primary C(sp3)−H bonds and can be used for the late‐stage C−H alkynylation of complex molecules.
Synthesis of 4-Alkyl-4-alkoxybutenolides Having Unsaturated Side Chains via Chromium Carbene Complex Photochemistry: (+)-Cerulenin
作者:Tracey E. Kedar、Michael W. Miller、Louis S. Hegedus
DOI:10.1021/jo960664k
日期:1996.1.1
photochemical reaction between optically active ene carbamates and chromium alkoxycarbene complexes containing unsaturated aliphatic side chains was further developed. Although remote olefinic groups, including conjugated dienes, were tolerated, a homoallylic side chain underwent intramolecularreaction to give a strained cyclobutanone. (+)-Cerulenin was synthesized utilizing the photochemical reaction of an
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