Diastereo- and Enantioselective Propargylation of Benzofuranones Catalyzed by Pybox-Copper Complex
摘要:
Diastereo- and enantioselective preparation of 2,2-disubstituted benzofuran-3(2H)-one has been realized by a pybox-copper catalyzed reaction between 2-substituted benzofuran-3(2H)-one and propargyl acetate. The utility of this method was demonstrated by further transformation of the terminal alkyne into a methyl ketone without loss of enantiomeric purity.
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
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
2-a]pyridines with exclusive regioselectivity in moderate to excellent yields has been developed. This cascade was initiated through propargylation of 2-aminopyridines at pyridine-nitrogen with propargylalcohol derivatives using Cu(II)-Pybox as catalyst and followed by an intramolecular cyclization and isomerization. Besides 2-aminopyridine, less reactive 2-aminopyrimidine, 2-aminopyrazine and 3-aminopyridazine
已经开发出一种高效的级联序列,用于合成2,3-二取代的咪唑并[1,2- a ]吡啶,具有中度到优异的排他选择性。该级联反应是通过使用铜(II)-Pybox作为催化剂在炔丙基醇衍生物上于吡啶氮原子处将2-氨基吡啶进行炔丙基化反应开始的,然后进行分子内环化和异构化。除了2-氨基吡啶,反应性较低的2-氨基嘧啶,2-氨基吡嗪和3-氨基哒嗪也适用于该级联反应。
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.
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。