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
New and Efficient Synthesis of 1,3-Dienylphosphonates by Palladium-Catalyzed Substitution of Propargylic Esters to Diethyl Phosphite
作者:Xiao-Ning Liu、Wei-Lei Guo、Chuan-Jin Hou、Xiang-Ping Hu
DOI:10.1080/00397911.2012.725795
日期:2013.10.2
Abstract An efficient route to the synthesis of 1,3-dienylphosphonates (1) has been developed for the first time by the substitution of propargylic esters (2) to the diethyl phosphite (3) nucleophile in the presence of Pd2(dba)3 · CHCl3 (2 mol %) and 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (4 mol%). Both the alkyl and aryl 1,3-dienylphosphonates can be prepared from this transformation. Supplemental
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。
Stereocontrol in Palladium-Catalyzed Propargylic Substitutions: Kinetic Resolution to give Enantioenriched 1,5-Enynes and Propargyl Acetates
作者:Michael J. Ardolino、Meredith S. Eno、James P. Morken
DOI:10.1002/adsc.201300720
日期:2013.11.25
Kineticresolution during the catalytic allyl-propargyl cross-coupling with chiral starting materials can be accomplished with a chiral Palladium catalyst. These reactions offer ready access to enantiomerically enriched enyne products from simple readily available starting materials.
Enantioselective Copper-Catalysed Propargylic Substitution: Synthetic Scope Study and Application in Formal Total Syntheses of (+)-Anisomycin and (−)-Cytoxazone
作者:Remko J. Detz、Zohar Abiri、Remi le Griel、Henk Hiemstra、Jan H. van Maarseveen
DOI:10.1002/chem.201003727
日期:2011.5.16
indoles excellent ee values were obtained (up to 98 % ee). The versatility of the propargylic amines obtained was demonstrated by their further elaboration to formaltotalsyntheses of the antibiotic (+)‐anisomycin and the cytokine modulator (−)‐cytoxazone.