Enantioselective Synthesis of Hemiaminals via Pd-Catalyzed C–N Coupling with Chiral Bisphosphine Mono-oxides
摘要:
A novel approach to hemiaminal synthesis via palladium-catalyzed C-N coupling with chiral bisphosphine mono-oxides is described. This efficient new method exhibits a broad scope, provides a highly efficient synthesis of HCV drug candidate elbasvir, and has been applied to the synthesis of chiral N,N-acetals.
Catalytic Enantioselective Synthesis of Lactams through Formal [4+2] Cycloaddition of Imines with Homophthalic Anhydride
作者:Claire L. Jarvis、Jennifer S. Hirschi、Mathew J. Vetticatt、Daniel Seidel
DOI:10.1002/anie.201612148
日期:2017.3.1
An amide‐thiourea compound, operating through a novel ion pairing mechanism, is an efficient organocatalyst for the asymmetric reaction of homophthalic anhydride with imines. N‐aryl and N‐alkyl imines readily undergo formal [4+2] cycloaddition to provide lactams with high levels of enantio‐ and diastereoselectivity. The nature of the key chiral ion pair intermediate was elucidated by DFT calculations
Ir-Catalyzed C−H Amidation of Aldehydes with Stoichiometric/Catalytic Directing Group
作者:Yun-Fei Zhang、Bin Wu、Zhang-Jie Shi
DOI:10.1002/chem.201603805
日期:2016.12.5
Ir‐catalyzed sp2 C−Hamidation of aldehydes with various anilines as stoichiometric or catalytic directing groups was accomplished. A wide range of substrates were selectively amidated in good to excellent yields with broad functional group tolerance. The iridacycle complexes were isolated, characterized, and proved as key intermediates. Kinetic studies and Hammett plots provided detailed understandings
用各种苯胺作为化学计量或催化方向的基团,对醛进行了Ir催化的sp 2 CH酰胺化反应。以良好的产率和优异的产率选择性选择性地酰胺化各种底物,并具有宽泛的官能团耐受性。分离,表征并证明了iridacycle复合物是关键中间体。动力学研究和Hammett图提供了对这种酰胺化反应的详细了解。根据机理,证明了富电子的ArSO 2 N 3对于分子间sp 3 CH酰胺化有效。
Visible-Light-Induced Radical Acylation of Imines with α-Ketoacids Enabled by Electron-Donor–Acceptor Complexes
作者:Hong-Hao Zhang、Shouyun Yu
DOI:10.1021/acs.orglett.9b01169
日期:2019.5.17
radical acylation of imines with α-ketoacids has been achieved, enabled by an electron-donor–acceptor (EDA) complex. This EDA complex-mediated process eradicates the use of a photocatalyst. Visiblelight is used as the sole promoter for this reaction, and CO2 is the only side product. Substrates with amide, cyanide, ester, ether, halides, and heterocycles were compatible. This radical acylation allows
Stereoselective Olefination and Regiospecific Vicinal Difunctionalization of Imines with α-(Benzothiazol-2-ylsulfonyl) Carbonyl Compounds
作者:You-Dong Shao、Xue-Song Wu、Shi-Kai Tian
DOI:10.1002/ejoc.201101684
日期:2012.3
Depending on their structures, imines are able to undergo either olefination or vicinal difunctionalization with various α-(benzothiazol-2-ylsulfonyl) carbonylcompounds in the absence of external bases. The olefination reaction of aromatic imines with α-(benzothiazol-2-ylsulfonyl) carbonylcompounds proceeds smoothly in tetrahydrofuran at 70 °C to give structurally diverse α,β-unsaturated esters,
Regio- and Chemoselective Kumada–Tamao–Corriu Reaction of Aryl Alkyl Ethers Catalyzed by Chromium Under Mild Conditions
作者:Xuefeng Cong、Huarong Tang、Xiaoming Zeng
DOI:10.1021/jacs.5b08621
日期:2015.11.18
the cross-coupling reactions with arylethers via C-O bond activation have attracted broad interest. However, the functionalizations of C-O bonds are mainly limited to nickel catalysis, and selectivity has long been a prominent challenge when several C-O bonds are present in the one molecule. We report here the first chromium-catalyzed selective cross-coupling reactions of arylethers with Grignard reagents
作为一种环境友好的合成工具,通过 CO 键活化与芳基醚的交叉偶联反应引起了广泛的兴趣。然而,CO 键的功能化主要限于镍催化,当一个分子中存在多个 CO 键时,选择性一直是一个突出的挑战。我们在这里报告了第一个铬催化的芳基醚与格氏试剂通过 CO(烷基)键断裂的选择性交叉偶联反应。在室温下使用简单、廉价的铬 (II) 预催化剂结合亚氨基助剂实现了多种转化。它为高效和选择性地构建官能化芳香醛提供了新途径。