[EN] A VERSATILE LIGAND FOR PALLADIUM-CATALYZED META-C-H FUNCTIONALIZATIONS<br/>[FR] LIGAND POLYVALENT POUR DES FONCTIONNALISATIONS DE MÉTA-C-H CATALYSÉES PAR DU PALLADIUM
申请人:SCRIPPS RESEARCH INST
公开号:WO2017184589A1
公开(公告)日:2017-10-26
A class of mono-protected 3-amino-2- hydroxypyridine (MPAHP) ligands that enable the meta- C-H arylation of anilines, phenols, phenylacetic acids, and biologically relevant heterocyclic compounds using norbornene as a transient mediator is disclosed. The applicability of this meta-arylation methodology in the pharmaceutical industry is illustrated for heteroaryl substrates and heteroaryl iodide coupling partners, a feat made possible by using the MPAHP ligand. The enabling nature of MPAHP ligands to achieve other meta-C-H functionalization processes is also illustrated by the development of a meta-C-H amination reaction and a meta-C-H alkynylation reaction.
Acylation of 2-benzylpyridine N-oxides and subsequent in situ [3,3]-sigamatropic rearrangement reaction
作者:Hua-qing Jing、Hong-liang Li、Jon C. Antilla
DOI:10.1016/j.tetlet.2020.152401
日期:2020.10
2-benzylpyridine N-oxides and their fast in situ [3,3]-sigmatropic rearrangement was reported. This transformation has a wide substrate scope under mild conditions, giving moderate to excellent yields. The application for the synthesis of chiral phenyl-2-pyridylmethanol products was briefly explored. Furthermore, an interesting example of tandem substitution and in situ [3,3]-sigamatropic rearrangement of 2-benzylpyridine
Palladium-Catalyzed Double C–H Functionalization of Arenes at the Positions <i>ortho</i> and <i>meta</i> to Their Directing Group: Concise Synthesis of Benzocyclobutenes
作者:Takeshi Nanjo、Chihiro Tsukano、Yoshiji Takemoto
DOI:10.1248/cpb.c16-00439
日期:——
The synthesis of benzocyclobutenes from simple arenes bearing a directing group was investigated via the palladium-catalyzed cyclization of norbornene derivatives. This approach allowed for the facile construction of benzocyclobutenes along with the double functionalization of the C–H bonds at the positions ortho and meta to the directing group. This result shows that the key palladacyclopentene intermediate in the Catellani reaction can be prepared by the directed double ortho C–H activation of the substrate. The results of this study also revealed that the combination of an N-protected amino acid with benzoquinone (BQ) was effective for this transformation.
Versatile ligand for palladium-catalyzed meta-C—H functionalizations of aromatic substrates
申请人:The Scripps Research Institute
公开号:US10696635B2
公开(公告)日:2020-06-30
A class of mono-protected 3-amino-2-hydroxypyridine (MPAHP) ligands that enable the meta-C—H arylation of anilines, phenols, phenylacetic acids, and biologically relevant heterocyclic compounds using norbornene as a transient mediator is disclosed, such as in the formation of a reaction product of Formula IA:
The applicability of this meta-arylation methodology in the pharmaceutical industry is illustrated for heteroaryl substrates and heteroaryl iodide coupling partners, a feat made possible by using the MPAHP ligand. The enabling nature of MPAHP ligands to achieve other meta-C—H functionalization processes is also illustrated by the development of a meta-C—H amination reaction and a meta-C—H alkynylation reaction.
Continuous Synthesis of Organozinc Halides Coupled to Negishi Reactions
作者:Nerea Alonso、L. Zane Miller、Juan de M. Muñoz、Jesus Alcázar、D. Tyler McQuade
DOI:10.1002/adsc.201400243
日期:2014.12.15
AbstractThe Negishi cross‐coupling is a powerful CC bond forming reaction. The method is less commonly used relative to other cross‐coupling methods in part due to lack of availability of organozinc species. While organozinc species can be prepared, problems with reproducibility and handling of these sensitive species can complicate these reactions. Herein, we describe the continuous formation, using an activated packed‐bed of metallic zinc, and subsequent use of organozinc halides. We demonstrate that a single column of zinc can provide excellent yields of organozinc halides and that they can be used downstream in subsequent Negishi cross‐couplings. The preparation of the zinc column and the scope of the reaction are discussed.magnified image