Synthesis of Natural Product-like Polyheterocycles via One-Pot Cascade Oximation, C–H Activation, and Alkyne Annulation
作者:Liyao Zheng、Yunhui Bin、Yunpeng Wang、Ruimao Hua
DOI:10.1021/acs.joc.6b01460
日期:2016.10.7
chroman-4-ones to tricyclic fused pyridines with the skeleton of cassiarins, a family of alkaloids with antimalarial activity, was developed. Also, a general strategy for modular construction of polyheterocycles with diverse natural product-like skeletons was developed by using ketone–alkyne bifunctional substrates. These reactions involved a one-pot cascade oximation of ketones, rhodium-catalyzed C–H activation
Isocanthine Synthesis via Rh(III)-Catalyzed Intramolecular C–H Functionalization
作者:Anthony Y. Chen、Qianqian Lu、Yao Fu、Richmond Sarpong、Brian M. Stoltz、Haiming Zhang
DOI:10.1021/acs.joc.7b02731
日期:2018.1.5
has been achieved using an intramolecular Rh(III)-catalyzed C–H functionalization of alkyne-tethered indoles in the presence of catalytic tris(acetonitrile)pentamethylcyclopentadienylrhodium(III) hexafluoroantimonate and stoichiometric copper(II) acetate. This isocanthine synthesis tolerates a variety of electronically diverse 5- or 6-substituted indoles with N-tethered alkyne coupling partners and can
Stereoselective Chromium‐Catalyzed Semi‐Hydrogenation of Alkynes
作者:Bernhard J. Gregori、Michal Nowakowski、Anke Schoch、Simon Pöllath、Josef Zweck、Matthias Bauer、Axel Jacobi von Wangelin
DOI:10.1002/cctc.202000994
日期:2020.11.5
very little applications as hydrogenation catalysts. Here, we report a Cr‐catalyzed semi‐hydrogenation of internal alkynes to the corresponding Z‐alkenes with good stereocontrol (up to 99/1 for dialkyl alkynes). The catalyst comprises the commercial reagents chromium(III) acetylacetonate, Cr(acac)3, and diisobutylaluminium hydride, DIBAL−H, in THF. The semi‐hydrogenation operates at mild conditions
Palladium‐Catalyzed Intermolecular Aryliodination of Internal Alkynes
作者:Yong Ho Lee、Bill Morandi
DOI:10.1002/anie.201812396
日期:2019.5.6
completely atom economical palladium‐catalyzed addition reaction has been developed to stereoselectively access functionalized tetrasubstituted alkenyl iodides. The palladium catalyst, which bears an electron‐poor bidentate ligand rarely employed in catalysis, is essential to promote the high yielding and chemoselective intermolecular reaction between equimolar amounts of an alkyne and an aryl iodide. This
An iron‐catalyzed diboration reaction of alkynes with bis(pinacolato)diboron (B2pin2) and external borating agents (MeOB(OR)2) affords diverse symmetrical or unsymmetrical cis‐1,2‐diborylalkenes. The simple protocol for the diboration reaction can be extended to the iron‐catalyzed carboboration of alkynes with primary and, unprecedentedly, secondary alkyl halides, affording various tetrasubstituted