Gold Redox Catalysis through Base‐Initiated Diazonium Decomposition toward Alkene, Alkyne, and Allene Activation
作者:Boliang Dong、Haihui Peng、Stephen E. Motika、Xiaodong Shi
DOI:10.1002/chem.201701970
日期:2017.8.16
The discovery of photoassisted diazonium activation toward gold(I) oxidation greatly extended the scope of goldredoxcatalysis by avoiding the use of a strongoxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert
通过避免使用强氧化剂,光辅助重氮盐向金(I)氧化活化的发现大大扩展了金氧化还原催化的范围。限制这种新型化学方法应用的一些实际问题是相对较低的效率(较长的反应时间和较低的转化率)和必须进行严格的反应条件控制(脱气和惰性反应环境)。在本文中,通过路易斯碱诱导的重氮活化已经开发出另一种无光条件。通过这种方法,将不活泼的Au I催化剂与Na 2 CO 3和重氮盐结合使用以生产Au III中间的。实现了对各种基质(包括炔烃,烯烃和丙二烯)的有效活化,然后快速进行了Au III还原消除,从而得到了具有良好收率或优异收率的C-C偶联产物。相对于以前报道的光活化方法,我们的方法通过更快的反应速率和更宽的反应范围提供了更高的效率和多功能性。在光引发条件下(<5%收率)不能活化的具有挑战性的底物,例如富电子/中性亚勒烯,可以被活化,随后以良好或优异的产率产生所需的偶联产物。
Photoredox-Catalyzed Intramolecular Aminodifluoromethylation of Unactivated Alkenes
作者:Zuxiao Zhang、Xiaojun Tang、Charles S. Thomoson、William R. Dolbier
DOI:10.1021/acs.orglett.5b01616
日期:2015.7.17
A photoredox catalyzed aminodifluoromethylation of unactivated alkenes has been developed in which HCF2SO2Cl is used as the HCF2 radical source. Sulfonamides were active nucleophiles in the final step of a tandem addition/oxidation/cyclization process to form pyrrolidines, and esters were found to cyclize to form lactones. Thus, a variety of pyrrolidines and lactones were obtained in moderate to excellent
已经开发出未活化的烯烃的光氧化还原催化的氨基二氟甲基化,其中HCF 2 SO 2 Cl用作HCF 2自由基源。在串联加成/氧化/环化过程的最后步骤中,磺酰胺是活性亲核试剂,以形成吡咯烷,发现酯可环化以形成内酯。因此,以中等至优异的产率获得了各种吡咯烷和内酯。为了使环化反应有效,铜催化剂(Cu(dap)2 Cl)和碳酸银的组合对于抑制竞争的氯二氟烷基化过程至关重要。
Copper(II)-Catalyzed Enantioselective Intramolecular Carboamination of Alkenes
作者:Wei Zeng、Sherry R. Chemler
DOI:10.1021/ja0762240
日期:2007.10.1
The reactions are catalyzed by chiral copper(II) complexes, and MnO2 is used as the inexpensive stoichiometric oxidant. A variety of five-membered heterocycles and a tetrahydroisoquinoline have been synthesized in good to excellent yields with good to excellent levels of enantioselectivity. This is the first reported copper-catalyzed enantioselective carboamination of alkenes.
介绍了用于合成氮杂环的 γ-烯基芳基磺酰胺和 δ-烯基芳基磺酰胺的对映选择性氧化环化。该反应由手性铜 (II) 配合物催化,MnO2 用作廉价的化学计量氧化剂。各种五元杂环和四氢异喹啉已以良好至极好的收率和良好至极好的对映选择性水平合成。这是首次报道的铜催化烯烃的对映选择性碳胺化。
Intermolecular Anti-Markovnikov Hydroamination of Unactivated Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer
作者:Qilei Zhu、David E. Graff、Robert R. Knowles
DOI:10.1021/jacs.7b11144
日期:2018.1.17
Here we report a catalytic method for the intermolecularanti-Markovnikovhydroamination of unactivated alkenes using primary and secondary sulfonamides. These reactions occur at room temperature under visible light irradiation and are jointly catalyzed by an iridium(III) photocatalyst, a dialkyl phosphate base, and a thiol hydrogen atom donor. Reaction outcomes are consistent with the intermediacy
在这里,我们报告了一种使用初级和次级磺酰胺对未活化烯烃进行分子间抗马尔科夫尼科夫加氢胺化的催化方法。这些反应在室温下在可见光照射下发生,并由铱 (III) 光催化剂、磷酸二烷基酯碱和硫醇氢原子供体共同催化。反应结果与通过磺酰胺 NH 键的质子耦合电子转移激活产生的 N 中心磺酰胺自由基的中间体一致。概述了反应的合成范围(> 60 个例子)和机械特征的研究。
Enantioselective Pd(II)-Catalyzed Intramolecular Oxidative 6-<i>endo</i> Aminoacetoxylation of Unactivated Alkenes
作者:Xiaoxu Qi、Chaohuang Chen、Chuanqi Hou、Liang Fu、Pinhong Chen、Guosheng Liu
DOI:10.1021/jacs.8b03767
日期:2018.6.20
A novel asymmetric 6-endo aminoacetoxylation of unactivatedalkenes by palladium catalysis, which yields chiral β-acetoxylated piperidines with excellent chemo-, regio- and enantioselectivities under very mild reaction conditions, has been established herein by employing a new designed pyridine-oxazoline (Pyox) ligand. Importantly, introducing a sterically bulky group into the C-6 position of Pyox