A General Strategy Toward Aromatic 1,2-Ambiphilic Synthons: Palladium-Catalyzed ortho-Halogenation of PyDipSi-Arenes
作者:Alexander S. Dudnik、Natalia Chernyak、Chunhui Huang、Vladimir Gevorgyan
DOI:10.1002/anie.201004426
日期:2010.11.8
A general and efficient strategy to synthesize 1,2‐ambiphilic aromatic and heteroaromatic synthons from haloarenes has been developed. The method involves installation of the PyDipSi directing group, and subsequent palladium‐catalyzed directed ortho‐halogenation of aryl silanes (see scheme; Py=2‐pyridyl). The usefulness of these 1,2‐ambiphilic building blocks was shown in their participation as both
Amino acid-promoted C–H alkylation with alkylboronic acids using a removable directing group
作者:Yu Zhang、Hang Jiang、Dushen Chen、Yanghui Zhang
DOI:10.1039/c6ob00674d
日期:——
Palladium-catalyzed C–H alkylation reaction with alkylboronic acids has successfully been developed using a removable pyridyldiisopropylsilyl directing group. The amino acid played a crucial role as a ligand in the reaction. The alkylation protocol is also applicable to the coupling of C(sp3)–H bonds with alkylboronic acids.
Pd‐Catalyzed C−H Alkylation of Arenes Using PyrDipSi, a Transformable and Removable Silicon‐Tethered Directing Group
作者:Dhruba Sarkar、Vladimir Gevorgyan
DOI:10.1002/chem.201602513
日期:2016.8
Pd‐catalyzed ortho‐C−H alkylation reaction of arenes using a transformable and removable Si‐tethered pyridyldiisopropylsilyl (PyrDipSi) directinggroup has been developed. In addition, the PyrDipSi directinggroup allows for an efficient sequential double‐fold C−H alkylation/oxygenation of arenes to produce meta‐alkylated phenols. This directinggroup can easily be removed or converted into valuable functionalities
Cobalt-Catalyzed <i>ortho</i>
-Methylation of Ferrocenes Bearing <i>ortho</i>
-Directing Groups by Catalytic Directed C-H Bond Activation
作者:David Schmiel、Holger Butenschön
DOI:10.1002/ejoc.201700358
日期:2017.6.8
Transition-metal-catalyzed C–H functionalization is an emerging powerful alternative to ortho-lithiation protocols. For ferrocene systems almost exclusively noble-metal catalysts have so far been used. Herein we present the first examples of cobalt-catalyzed ortho-methylations by C–Hactivation at ferrocenes bearing various ortho-directing groups (ODGs). The cobalt-catalyzed ortho-methylation results