Cobalt-Catalyzed C–H Activation and [3 + 2] Annulation with Allenes: Diastereoselective Synthesis of Indane Derivatives
作者:Arnab Dey、Chandra M. R. Volla
DOI:10.1021/acs.orglett.1c01521
日期:2021.7.2
ve [3 + 2] annulation reaction has been achieved, employing allenes as the annulation partners. The selective 2,3-migratory insertion of allenes with arylcobalt(III) species and the subsequent intramolecular diastereoselective nucleophilic addition of η1-allylcobalt onto the imine resulted in [3 + 2] annulation over the alternative [4 + 2] annulation. Furthermore, the oxidative annulation obviates
Cobalt-catalyzed highly diastereoselective [3 + 2] carboannulation reactions: facile access to substituted indane derivatives
作者:Arnab Dey、Anurag Singh、Chandra M. R. Volla
DOI:10.1039/d1cc05245d
日期:——
Efficient oxidative [3 + 2] annulation reaction involving aryl hydrazones and heterobicyclic alkenes has been realized with inexpensive and earth-abundant cobalt salts under aerobic conditions. The reaction proceeds via directing-group-assisted C–H activation and exo-selective migratory insertion, followed by the intramolecular nucleophilic attack of the alkylcobalt(III) species onto the imine with
Traceless heterocycle synthesis based on transition-metal-catalyzed C-H functionalization is synthetically appealing but has been realized only in monodentate directing systems. Bidentate directing systems allow for the achievement of high catalytic reactivity without the need for a high-cost privileged ligand. The first bidentate directing-enabled, traceless heterocycle synthesis is demonstrated in the
Traceless Bidentate Directing Group Assisted Cobalt-Catalyzed <i>sp</i><sup>2</sup>-C–H Activation and [4 + 2]-Annulation Reaction with 1,3-Diynes
作者:Arnab Dey、Chandra M. R. Volla
DOI:10.1021/acs.orglett.0c02664
日期:2020.10.2
cobalt-catalyzed [4 + 2] annulation of hydrazones and 1,3-diynes has been developed for the synthesis of 3-alkynylated isoquinolines engaging 2-aminopyridine as a traceless bidentate directinggroup. The strategy has been successfully extended for the synthesis of 3,3′-biisoquinoline moieties via both one-pot as well as sequential approaches. The utilization of a traceless bidentate directinggroup with an inexpensive