A novel mild, visible‐light‐induced palladium‐catalyzed hydrogenatom translocation/atom‐transfer radical cyclization (HAT/ATRC) cascade has been developed. This protocol involves a 1,5‐HAT process of previously unknown hybrid vinyl palladium radical intermediates, thus leading to iodomethyl carbo‐ and heterocyclic structures.
Metal-Free, One-Pot Cascade Annulation of 2-Pyrones in Water for the Synthesis of Peptidomimetics
作者:Wannaporn Disadee、Anek Lekky、Somsak Ruchirawat
DOI:10.1021/acs.joc.9b01856
日期:2020.2.21
formation, decarboxylation or esterification, isomerization, and lactamization, to furnish bicyclic 2-pyridones in up to 98% yield with retention of the chirality at the α-carbon of the amino acid portion of the molecule. Exploration of the substrate scope revealed some selectivity between the decarboxylation and esterification pathways under thermal acidic conditions, while performing the reaction in boiling
Cu-Catalyzed Site-Selective and Enantioselective Ring Opening of Cyclic Diaryliodoniums with 1,2,3-Triazoles
作者:Zengyin Chao、Mingming Ma、Zhenhua Gu
DOI:10.1021/acs.orglett.0c02256
日期:2020.8.21
A Cu-catalyzed enantioselective ring-opening/triazolylation reaction is reported. The reaction shows excellent chemoselectivity regarding the three different nitrogen atoms of 1,2,3-triazoles. The optically enriched axially chiral aryl iodides thus obtained were readily derivatized to different types of chiral phosphine ligands and their corresponding copper or palladium complexes.
Grubbs Metathesis Enabled by a Light‐Driven
<i>gem</i>
‐Hydrogenation of Internal Alkynes
作者:Tobias Biberger、Raphael J. Zachmann、Alois Fürstner
DOI:10.1002/anie.202007030
日期:2020.10.12
complexes instigate a light‐drivengem‐hydrogenation of internal alkynes with concomitant formation of discrete Grubbs‐type ruthenium carbene species. This unorthodox reactivity mode is harnessed in the form of a “hydrogenative metathesis” reaction, which converts an enyne substrate into a cyclic alkene. The intervention of ruthenium carbenes formed in the actual gem‐hydrogenation step was proven by the