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。
Palladium-Catalyzed Intramolecular Aminoacetoxylation of Unactivated Alkenes with Hydrogen Peroxide as Oxidant
作者:Haitao Zhu、Pinhong Chen、Guosheng Liu
DOI:10.1021/acs.orglett.5b00373
日期:2015.3.20
A palladium-catalyzed intramolecular aminoacetoxylation of unactivated alkenes was developed in which H2O2 was used as the sole oxidant. A variety of 3-acetoxylated piperidines were obtained in good yields with good to excellent regio- and diastereoselectivities. Mechanistic study revealed that the addition of di(2-pyridyl) ketone (dpk) ligand was crucial to promote the oxidative cleavage of the C–Pd(II)
开发了钯催化的未活化烯烃的分子内氨基乙酰氧基化反应,其中H 2 O 2被用作唯一的氧化剂。以良好的产率获得了各种3-乙酰氧基化的哌啶,具有良好或优异的区域和非对映选择性。机理研究表明,添加二(2-吡啶基)酮(dpk)配体对于促进H 2 O 2氧化C-Pd(II)键产生C-OAc键至关重要。
Manganese-Catalyzed N–F Bond Activation for Hydroamination and Carboamination of Alkenes
the precatalyst and a cheap silane, (MeO)3SiH, as both the hydrogen-atom donor and the F-atom acceptor, enabling intramolecular/intermolecular hydroaminations of alkenes, two-component carboamination of alkenes, and even three-component carboamination of alkenes. A wide range of valuable aliphatic sulfonamides can be readily prepared using these practical reactions.
Regio- and Enantioselective Aminofluorination of Alkenes
作者:Wangqing Kong、Pascal Feige、Teresa de Haro、Cristina Nevado
DOI:10.1002/anie.201208471
日期:2013.2.25
Enantio‐ and regioselective: The intramolecular enantioselective aminofluorination of unactivated olefins was achieved by using a chiral iodo(III) difluoride salt. A highly regioselective aminofluorination of styrenes to access 2‐fluoro‐2‐phenylethanamines was also developed.
[reaction: see text] Various ene-tosylynamides react with platinum(II) chloride and lead to bicyclic nitrogenated heterocycles. This unprecedented and easily operated process can be coupled with a hydrolysis of the intermediate cyclic tosylenamides in a one-pot transformation, which provides cyclobutanones.