Sterically Controlled, Palladium-Catalyzed Intermolecular Amination of Arenes
作者:Ruja Shrestha、Paramita Mukherjee、Yichen Tan、Zachary C. Litman、John F. Hartwig
DOI:10.1021/ja4032677
日期:2013.6.12
the Pd-catalyzed amination of arenes to form N-aryl phthalimides with regioselectivity controlled predominantly by steric effects. Mono-, di-, and trisubstituted arenes lacking a directing group undergo amination reactions with moderate to high yields and high regioselectivities from sequential addition of PhI(OAc)2 as an oxidant in the presence of Pd(OAc)2 as catalyst. This sterically derived selectivity
Organosilicon compounds are important reagents and synthetic intermediates that play a key role in the construction of new materials and complex products. Here we show a highly diastereoselective rhodium-catalyzed cycloisomerization of 1,6-dienes, in which the use of (EtO)3SiH accelerates the intramolecular cyclization reaction to afford a novel spiro-fused succinimide and pyrazolone derivatives in moderate
有机硅化合物是重要的试剂和合成中间体,在新材料和复杂产品的构建中起着关键作用。在这里,我们展示了一种高度非对映选择性的铑催化的 1,6-二烯环化异构化,其中使用 (EtO) 3 SiH 加速了分子内环化反应,以中等至优异的产率提供了新型螺稠合琥珀酰亚胺和吡唑啉酮衍生物。单一的非对映异构体。所提出的机制涉及来自氢硅烷的活性 Rh-H 物质,该物质是该螺型环异构化反应中的 H 供体。
Chiral Amine Thiourea-Promoted Enantioselective Michael Addition Reactions of 3-Substituted Benzofuran-2(3<i>H</i>)-ones to Maleimides
A highly diastereo- and enantioselective Michael addition reaction with respect to prochiral 3-substituted benzofuran-2(3H)-ones and maleimides by a chiral bifunctional thiourea−tertiary amine catalyst was investigated. The corresponding adducts, containing a quaternary center at the C3-position of the benzofuran-2(3H)-one as well as a vicinal tertiary center, were generally obtained in high yields
Photocatalyzed Reverse Polarity Oxidative Povarov Reaction of Glycine Derivatives with Maleimides
作者:Yongxin Zhang、Wei Jiang、Xiazhen Bao、Yifeng Qiu、Yong Yuan、Caixia Yang、Congde Huo
DOI:10.1002/cjoc.202100401
日期:2021.12
An oxidative tandem (4+2)-cyclization/aromatization of N-aryl glycine derivatives with electron-deficient alkenes was first achieved using Ru(bpy)3Cl2 as a photocatalyst and TBHP as an oxidant in combination with visible-light irradiation by blue LEDs. One-electron oxidation and the following α-deprotonation of glycine derivatives afford α-amino alkyl radicals, which were then trapped by electrophilic
guanidine-catalyzed Michael addition of 3-benzyl substituted oxindoles to N-maleimides has been developed to produce oxindolederivatives with a quaternary carbon chiral center at the 3-position in excellent yields and enantio- and diastereoselectivities. This is the first incorporation of N-benzylic alpha-branched succinimides into 3,3-disubstituted oxindoles.