Cobalt-Catalyzed Cyclization/Hydroboration of 1,6-Diynes with Pinacolborane
作者:Qiang Huang、Meng-Yang Hu、Shou-Fei Zhu
DOI:10.1021/acs.orglett.9b02873
日期:2019.10.4
Herein, we report a protocol for cyclization/hydroboration of 1,6-diynes with pinacolborane using a cobalt catalyst generated in situ from a Co(II)-phenanthroline complex, tetrabutylammonium fluoride, and pinacolborane. This protocol, which features good functional group tolerance, a broad substrate scope, and excellent stereoselectivity, enables the synthesis of useful cyclic 1,3-dienylboron compounds
Photoinduced Ligand-to-Metal Charge Transfer Enables Photocatalyst-Independent Light-Gated Activation of Co(II)
作者:Benjamin D. Ravetz、Jason Y. Wang、Kyle E. Ruhl、Tomislav Rovis
DOI:10.1021/acscatal.8b04326
日期:2019.1.4
Photoredoxcatalysis can be used to manipulate the redox state of a transitionmetalcomplex leading to the desired reactivity. While powerful, obviating the role of the second catalyst would be attractive from the perspective of simplifying the protocol and using visible light to uncover unexpected, enabling reactivity. Herein we report that Co-acetylides, formed in situ, are photoactive complexes
A Pd‐Au alloy efficiently catalyzed the [2+2+2] cycloaddition of substituted alkynes. Whereas monometallic Pd and Au catalysts were totally ineffective, Pd‐Au alloy nanoparticle catalysts with a low Pd/Au molar ratio showed high activity to give the corresponding polysubstituted arenes in high yields. A variety of substituted alkynes participated in various modes of cycloaddition under Pd‐Au alloy
Silver-Mediated [2 + 2 + 1] Cyclization Reaction of Diynes with Elemental Selenium/Sulfur To Synthesize 3,4-Substituted Cyclopenta[<i>c</i>]selenophenes/Cyclopenta[<i>c</i>]thiophenes
作者:Ye Wang、Yang Yuan、Zongkang Wang、Yingge Gu、Siyi Fu、Lingkai Kong、Yanzhong Li
DOI:10.1021/acs.orglett.1c02018
日期:2021.8.6
An efficient and atom-economical silver-mediated [2 + 2 + 1] cyclization protocol for the synthesis of 3,4-fused-ring-substituted and 2,5-unsubstituted selenophenes or thiophenes has been developed. Two C–Se/C–S bonds and one C–C bond were rapidly constructed in one step. Readily accessible substrates, commercially available elemental selenium/sulfur, and good functional group tolerance make this procedure