New chiral phosphorus–olefin hybrid ligands derived from the rigid “privileged” l‐proline have been conveniently prepared and applied in the rhodium‐catalyzed asymmetric arylation of electron‐deficient olefins with arylboronic acids at room temperature; this reaction provides the desired products in excellent yields and high enantioselectivities. The origin of observed stereoselectivity has been investigated
Development of Modifiable Bidentate Amino Oxazoline Directing Group for Pd-Catalyzed Arylation of Secondary CH Bonds
作者:Kang Chen、Zhao-Wei Li、Peng-Xiang Shen、Hong-Wei Zhao、Zhang-Jie Shi
DOI:10.1002/chem.201406528
日期:2015.5.11
A novel bidentate α‐amino oxazolinyl directinggroup has been developed. Different from previous directinggroups, this newly designed directinggroup was easily prepared from amino acids and modified in structure. This auxiliary preferentially effects functionalization at secondaryC(sp3)Hbonds, rather than at aryl C(sp2)Hbonds. The diastereoselectivity of directarylation between geminal secondary
unique diamidine ligand catalyzes asymmetric NaBH4 reduction of C3‐disubstituted (E)‐ and (Z)‐2‐propenoates, including C3‐oxygen‐ and nitrogen‐substituted substrates with high enantioselectivity. Analysis by X‐ray diffraction, 1H NMR spectroscopy, ring‐opening radical‐clock and D‐labeling reactions, and the structure/selectivity relationship suggest that a mechanism of CoH‐involved non‐single‐electron transfer
独特的二am基配体的新Co络合物催化NaBH 4还原不对称还原C3-二取代的(E)和(Z)-2-丙烯酸酯,包括具有高对映选择性的C3-氧和氮取代的底物。X射线衍射,1 H NMR光谱,开环自由基钟和D标记反应以及结构/选择性关系的分析表明,CoH参与的非单电子转移1,4加成的机理有所不同C2对映体。新型CoH 2(BH 3)2配合物的定量分离已支持了CoH物种的参与。
Palladium-Catalyzed Asymmetric Arylation of C(sp<sup>3</sup>)–H Bonds of Aliphatic Amides: Controlling Enantioselectivity Using Chiral Phosphoric Amides/Acids
作者:Shao-Bai Yan、Song Zhang、Wei-Liang Duan
DOI:10.1021/acs.orglett.5b00968
日期:2015.5.15
Enantioselective arylation of secondary beta-C(sp(3))-H bonds of 8-aminoquinoline amides was realized with a palladium catalyst. Chiral phosphoric amides and acids were used for the first time to control the stereoselectivity at the C-H bond cleavage step in the C-H activation reactions.
Enantio‐ and Regioselective NiH‐Catalyzed Reductive Hydroarylation of Vinylarenes with Aryl Iodides
作者:Yuli He、Chuang Liu、Lei Yu、Shaolin Zhu
DOI:10.1002/anie.202010386
日期:2020.11.23
A highly enantio‐ and regioselectivehydroarylation process of vinylarenes with aryl halides has been developed using a NiH catalyst and a new chiral bis imidazoline ligand. A broad range of structurally diverse, enantioenriched 1,1‐diarylalkanes, a structure found in a number of biologically active molecules, have been obtained with excellent yields and enantioselectivities under extremely mild conditions