Ligand-Enabled Methylene C(sp3)–H Bond Activation with a Pd(II) Catalyst
摘要:
Pd(II) insertion into beta-methylene C(sp(3))-H bonds was enabled by a mutually repulsive and electron-rich quinoline ligand. Ligand tuning led to the development or a method that allows for installation of an aryl,, group On a range of acyclic and cyclic amides containing beta-methylene C(sp(3))-H bonds.
[EN] LIGAND-CONTROLLED C(SP3)-H ARYLATION AND OLEFINATION IN SYNTHESIS OF UNNATURAL CHIRAL ALPHA AMINO ACIDS<br/>[FR] ARYLATION COMMANDÉE PAR LIGAND DE C(SP3)-H ET OLÉFINATION UTILISABLES DANS LE CADRE DE LA SYNTHÈSE D'ACIDES ALPHA-AMINÉS CHIRAUX NON NATURELS
申请人:SCRIPPS RESEARCH INST
公开号:WO2015131100A1
公开(公告)日:2015-09-03
The use of ligands to tune the reactivity and selectivity of transition metal-catalysts for C(-sp3)-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp3)-H arylation using pyridine and quinoline derivatives: the former promotes exclusive monoarylation, whereas the latter activates the catalyst further to achieve diarylation. Successive application of these ligands enables the sequential diarylation of a methyl group in an alanine derivative with two different aryl iodides, affording a wide range of β-Ar-p-Ar ' -cc-amino acids with excellent levels of diastereoselectivity (d.r. > 20:1). Both configurations of the β-chiral center can be accessed by choosing the order in which the aryl groups are installed. The use of a quinoline derivative as a ligand also enables C(sp3)-H olefination of a protected alanine.
Pd(II)-catalyzed Enantioselective Beta-Methylene C(sp3)–H Bond Activation
申请人:The Scripps Research Institute
公开号:US20190315710A1
公开(公告)日:2019-10-17
Chiral acetyl-protected aminoethyl quinoline (APAQ), pyridine and imazoline ligands are disclosed that enable Pd (II)-catalyzed enantioselective arylation or heteroarylation of ubiquitous prochiral β-methylene C—H bonds of aliphatic amides offers an alternative disconnection for constructing β-chiral centers. Systematic tuning of the ligand structure reveals that a six-membered instead of a five-membered chelation of these types of ligands with the Pd(II) is important for accelerating the C(sp
3
)-H activation thereby achieving enantioselectivity for quinoline and pyridine ligands.
[EN] LIGAND-ENABLED META-C-H ACTIVATION USING A TRANSIENT MEDIATOR<br/>[FR] ACTIVATION DE MÉTA-C-H PERMISE PAR UN LIGAND UTILISANT UN MÉDIATEUR TRANSITOIRE
申请人:SCRIPPS RESEARCH INST
公开号:WO2016123361A1
公开(公告)日:2016-08-04
An alternative approach to formation of a C-C bond at a meta-position of an aromatic compound is disclosed that employs an ethylenically unsaturated bicyclic compound as a transient mediator to achieve meta-selective C-H activation with a simple and common ortho-directing group. The use of a pyridine-based ligand assists in relaying the palladium catalyst to the meta-position by the unsaturated bicyclic compound following initial ortho-C-H activation.
Ligand-enabled meta-C-H activation using a transient mediator
申请人:Yu Jin-Quan
公开号:US10611723B2
公开(公告)日:2020-04-07
An alternative approach to formation of a C—C bond at a meta-position of an aromatic compound is disclosed that employs an ethylenically unsaturated bicyclic compound as a transient mediator to achieve meta-selective C—H activation with a simple and common ortho-directing group. The use of a pyridine-based ligand assists in relaying the palladium catalyst to the meta-position by the unsaturated bicyclic compound following initial ortho-C—H activation.
[EN] QUATERNARY TRIPHENYLPHOSPHONIUM SALT COMPOUND, PREPARATION METHOD THEREFOR, AND USES THEREOF<br/>[FR] COMPOSÉ DE SEL DE TRIPHÉNYL-PHOSPHONIUM QUATERNAIRE, SON PROCÉDÉ DE PRÉPARATION ET SON APPLICATION<br/>[ZH] 一类三苯基鏻盐化合物及其制备方法与应用