A mild rhodium catalytic system has been developed to synthesize vinylcyclopropa[b]indolines through cyclopropanation of indoles with vinyl carbenoids generated from ringopening of cyclopropenes in situ. By employing a Rh-migration strategy, the products can be obtained with good to excellent E:Z ratios (≤99:1) and complete diastereoselectivity (≤99:1). This method is easy, has a low catalyst loading
已开发出一种温和的铑催化体系,通过将吲哚与原位环丙烯开环生成的乙烯基类胡萝卜素进行环丙烷化,来合成乙烯基环丙烷[ b ]二氢吲哚。通过采用Rh迁移策略,可以获得具有良好或优异的E:Z比(≤99:1)和完全非对映选择性(≤99:1)的产物。该方法容易,催化剂负载低并且适用于广泛的功能。
Asymmetric Nitrone Synthesis via Ligand-Enabled Copper-Catalyzed Cope-Type Hydroamination of Cyclopropene with Oxime
We report realization of the first enantioselective Cope-type hydroamination of oximes for asymmetric nitrone synthesis. The ligand promoted asymmetriccyclopropene “hydronitronylation” process employs a Cu-based catalytic system and readily available starting materials, operates under mild conditions and displays broad scope and exceptionally high enantio- and diastereocontrol. Preliminary mechanistic
structures are important components of biologically active natural products and pharmaceuticals. We herein report the enantioselective intermolecularhydroamination of substituted cyclopropenes with various amines catalyzed by chiral half‐sandwich rare‐earth‐metal complexes. This method constitutes a 100 % atom‐efficient route for the synthesis of a variety of chiral α‐aminocyclopropane derivatives in high
atom-efficient route for the synthesis of a wide range of enantioenriched alkynylcyclopropane derivatives in high yields (65–96%) and excellent stereoselectivity (>20:1 dr; 90–99% ee). Elaboration of some of the alkynylcyclopropane products through selective transformation of the C≡C moiety has also been demonstrated to give further diversified chiral cyclopropane derivatives which are otherwise difficult
[(NHC)Ni
<sup>II</sup>
H]‐Catalyzed Cross‐Hydroalkenylation of Cyclopropenes with Alkynes: Cyclopentadiene Synthesis by [(NHC)Ni
<sup>II</sup>
]‐Assisted C−C Rearrangement
作者:Jian‐Qiang Huang、Chun‐Yu Ho
DOI:10.1002/anie.201901255
日期:2019.4.16
achieved for the first time by using new [(NHC)Ni(allyl)]BArF catalysts (NHC=N‐heterocyclic carbenes). By controlling the (NHC)NiIIH relative insertion reactivity with cyclopropene and alkyne, a broad scope of cyclopentadienes was obtained with highly selectively. The structural features of the new (NHC)NiII catalyst were important for the success of the reaction. The mild reaction conditions employed may
通过使用新的[(NHC)Ni(烯丙基)] BAr F催化剂(NHC = N杂环卡宾),首次使用环丙烯和炔烃作为底物对实现了交叉氢烯基化/重排级联反应(HARC )。通过控制(NHC)Ni II H与环丙烯和炔烃的相对插入反应性,可以高度选择性地获得宽范围的环戊二烯。新型(NHC)Ni II催化剂的结构特征对于反应成功至关重要。所采用的温和反应条件可以作为探索(NHC)Ni II辅助的乙烯基环丙烷重排反应性的入口。