β-unsaturated N-tosylamides via N-sulfonyl ketenimine formation followed by a probable 1,3-OAc migration ([3,3]-sigmatropic rearrangement). The reaction is very general, allowing all kinds of substitution, including alkyl, aryl (electron-donating, -withdrawing, and -neutral), heteroaryl, and vinylgroups, on the C-terminal of acrylamide. Also, the method affords the products at ambient temperature
Enantioselective Copper-Catalyzed Formal [4 + 2] Cycloaddition of <i>o</i>-Aminophenol Derivatives with Propargylic Esters for Synthesis of Optically Active 3,4-Dihydro-2<i>H</i>-1,4-benzoxazines
作者:Zhen-Ting Liu、Ya-Hui Wang、Fu-Lin Zhu、Xiang-Ping Hu
DOI:10.1021/acs.orglett.6b00322
日期:2016.3.4
The first copper-catalyzed asymmetric formal [4 + 2] cycloaddition of o-aminophenol derivatives with propargylic esters as the bis-electrophilic C2 synthons for the stereoselective construction of chiral 2,3,4-trisubstituted 2H-1,4-benzoxazines bearing an exocyclic double bond has been developed. By using a structurally modified chiralketimineP,N,N-ligand, a wide range of optically active 2H-1,4-benzoxazines
首次铜催化邻氨基苯酚衍生物与炔丙酸酯作为双亲电子C2合成子的不对称[4 + 2]环加成,用于立体选择性地构建手性2,3,4-三取代的2 H -1,4-苯并恶嗪轴承已经开发了环外双键。通过使用结构改性的手性酮亚胺P,N,N-配体,可以高收率和极好的对映选择性(高达97%ee)制备各种光学活性的2 H -1,4-苯并恶嗪。
Enantioconvergent Copper Catalysis: <i>In Situ</i> Generation of the Chiral Phosphorus Ylide and Its Wittig Reactions
highly functionalized chiral P-ylides can be easily synthesized through a copper-catalyzed asymmetric propargylic alkylation reaction from phosphonium salts and racemic propargylic esters. The subsequent Wittig reactions enable the synthesis of versatile alkene building blocks, chiral α-propargylic acrylates, and α-propargylic allenoates, with a wide substrate scope and satisfactory functional group
Copper-catalyzed intermolecular asymmetric propargylic dearomatization of phenol derivatives
作者:Long Shao、Xiang-Ping Hu
DOI:10.1039/c7cc03034g
日期:——
A copper-catalyzed intermolecular asymmetric propargylic dearomatization of phenol derivatives has been realized. Under the catalysis of Cu(OTf)·1/2C6H6 decorated with a chiral tridentate ketimineP,N,N-ligand, the dearomatization reaction proceeded smoothly with excellent control of chemo-, regio-, and enantioselectivities, thus providing a variety of optically active cyclohexadienone derivatives
已经实现了铜催化的苯酚衍生物的分子间不对称炔丙基脱芳香化反应。在手性三齿酮亚胺P,N,N-配体修饰的Cu(OTf)·1 / 2C 6 H 6的催化下,脱芳香化反应顺利进行,对化学,区域和对映体的选择性得到很好的控制。多种光学活性环己二烯酮衍生物,ee最高可达99%以上。
Copper-Catalyzed Enantioselective Propargylic Amination of Propargylic Esters with Amines: Copper−Allenylidene Complexes as Key Intermediates
and limitations of the copper-catalyzedpropargylicamination of various propargylic esters with amines are presented, where optically active diphosphines such as Cl-MeO-BIPHEP and BINAP work as good chiral ligands. A variety of secondary amines are available as nucleophiles for this catalytic reaction to give the corresponding propargylic amines with a high enantioselectivity. The results of some stoichiometric