Cobalt-Catalyzed Asymmetric Markovnikov Hydroboration of Styrenes
作者:Xu Chen、Zhaoyang Cheng、Zhan Lu
DOI:10.1021/acscatal.8b05135
日期:2019.5.3
A cobalt-catalyzed asymmetric hydroboration of styrenes using an imidazoline phenyl picoliamide (ImPPA) ligand was first reported to deliver the valuable chiral secondary organoboronates with good functional tolerance and highenantioselectivity (up to >99% ee). This protocol is operationally simple without any activator. Particularly, this method can be applied in the asymmetric hydroboration of allylamine
Regiospecific <i>ortho</i>
-C−H Allylation of Benzoic Acids
作者:A. Stefania Trita、Agostino Biafora、Martin Pichette Drapeau、Philip Weber、Lukas J. Gooßen
DOI:10.1002/anie.201712520
日期:2018.10.26
developed and it allows the regiospecific introduction of allyl residues to benzoicacids. In the presence of a [Ru(p‐cymene)Cl2]2 and K3PO4, benzoicacids react with allyl acetates at only 50 °C to give the corresponding ortho‐allylbenzoic acids. The protocol is generally applicable to both electron‐rich and electron‐poor benzoicacids in combination with linear and branched allyl acetates. The products
已经开发出了一种羧酸盐定向的邻-CH功能基,可以将烯丙基残基的区域特异性引入苯甲酸中。在[Ru(p- cymene)Cl 2 ] 2和K 3 PO 4存在下,苯甲酸在仅50°C的条件下与乙酸烯丙酯反应,生成相应的邻-烯丙基苯甲酸。该方案通常适用于富电子和贫电子的苯甲酸与直链和支链乙酸烯丙酯的组合。可以通过双键迁移,内酯化或脱羧等方法在原位进一步对产品进行功能化。
Ligand Relay Catalysis Enables Asymmetric Migratory Reductive Acylation of Olefins or Alkyl Halides
is challenging, especially in asymmetric transformations. With each step in the catalytic cycle promoted by its privileged ligand and different steps well-connected by dynamic ligand exchange, synergistic combination of multiple ligands could potentially enhance the catalytic efficiency and selectivity. Now, this concept has been applied to the NiH-catalyzed asymmetric remote hydroacylation of olefins
dehydrogenation-based strategy for enantioselective formal benzylic C(sp3)–H bond borylation. Dehydrogenation of alkylarenes by a pincer-Ir complex produces arylalkenes via a tandem dehydrogenation/alkene-isomerization catalysis. The subsequent Cu-catalyzed asymmetric alkenehydroboration affords benzylic boronate esters with excellent site- and enantioselectivity. The generality of this strategy has
直接不对称烷基官能化可以潜在地将丰富且廉价的烃原料转化为增值的手性精细化学品。在这里,我们报告了一种基于脱氢的一锅法,用于对映选择性形式苄基 C(sp 3 )-H 键硼化。通过钳形铱络合物对烷基芳烃的脱氢通过串联脱氢/烯烃异构化催化产生芳基烯烃。随后的 Cu 催化的不对称烯烃硼氢化提供了具有优异位点和对映选择性的苄基硼酸酯。不对称烷基胺化进一步证明了该策略的普遍性。
Catalyst-Controlled Intermolecular Homobenzylic C(sp<sup>3</sup>)–H Amination for the Synthesis of β-Arylethylamines
The combination of a tailored sulfamate with a C4-symmetrical rhodium(II) tetracarboxylate allows to uncover a selective intermolecularamination of unactivated homobenzylic C(sp3)–H bonds. The reaction has a broad scope (>30 examples) and proceeds with a high level of regioselectivity with homobenzylic/benzylic ratio of up to 35:1, thereby providing a direct access to β-arylethylamines that are of