Organic Ligand-Free Alkylation of Amines, Carboxamides, Sulfonamides, and Ketones by Using Alcohols Catalyzed by Heterogeneous Ag/Mo Oxides
作者:Xinjiang Cui、Yan Zhang、Feng Shi、Youquan Deng
DOI:10.1002/chem.201001915
日期:2011.1.17
that is, amines, carboxamides, sulfonamides, and ketones, were successfully synthesized through a borrowing‐hydrogen mechanism. Up to 99 % isolated yields were obtained under relatively mild conditions without additive organic ligand. The catalytic process shows promise for the efficient and economic synthesis of amine, carboxamide, sulfonamide, and ketone derivatives because of the simplicity of the
复杂且昂贵的有机配体通常在制备或工业水平的精细化学合成中必不可少。通过使用不具有添加剂有机配体的非均相催化剂体系来合成精细化学品是非常合乎需要的,但由于它们的通用性差和严格的反应条件而受到严格限制。在这里,我们显示了具有特定Ag 6 Mo 10 O 33的Ag / Mo杂化材料催化形成碳-氮或碳-碳键的结果晶体结构。通过借氢机制成功合成了48种含氮或氧的化合物,即胺,羧酰胺,磺酰胺和酮。在没有添加剂有机配体的条件下,在相对温和的条件下可获得高达99%的分离产率。催化过程显示出胺,羧酰胺,磺酰胺和酮衍生物的高效经济合成的希望,因为该系统简单且易于操作。
Manganese-Catalyzed <i>N</i>-Alkylation of Sulfonamides Using Alcohols
作者:Benjamin G. Reed-Berendt、Louis C. Morrill
DOI:10.1021/acs.joc.9b00203
日期:2019.3.15
An efficient manganese-catalyzed N-alkylation of sulfonamides has been developed. This borrowing hydrogen approach employs a well-defined and bench-stable Mn(I) PNP pincer precatalyst, allowing benzylic and simple primary aliphatic alcohols to be employed as alkylating agents. A diverse range of aryl and alkyl sulfonamides undergoes mono-N-alkylation in excellent isolated yields (32 examples, 85% average
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron‐Rich Substrates
作者:Sayad Doobary、Alexi T. Sedikides、Henry P. Caldora、Darren L. Poole、Alastair J. J. Lennox
DOI:10.1002/anie.201912119
日期:2020.1.13
oxidative difluorination of alkenes represents an important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their safety and scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products
Enantioselective Synthesis of <i>trans</i>
-Vicinal Diamines <i>via</i>
Rhodium-Catalyzed [2+2] Cycloaddition of Allenamides
作者:Wei-Feng Zheng、Gui-Jun Sun、Liang Chen、Qiang Kang
DOI:10.1002/adsc.201800021
日期:2018.5.2
An efficient protocol for the enantioselective Rh‐catalyzed intermolecular head‐to‐head [2+2] cycloaddition of allenamides was developed. A variety of enantio‐enriched cyclobutane‐1,2‐diamine derivatives were achieved in good yields with good to excellent enantioselectivities.
Copper-Catalyzed Silylation of C(sp<sup>3</sup>)–H Bonds Adjacent to Amide Nitrogen Atoms
作者:Jian-Jun Feng、Martin Oestreich
DOI:10.1021/acs.orglett.8b01698
日期:2018.7.20
copper-catalyzed C–Si bond formation between N-halogenated amides and Si–B reagents is described. This oxidative coupling enables the silylation of C(sp3)–H bonds α to an amide nitrogen atom. The utility of the new method is demonstrated for sulfonamides, and N-chlorination with tBuOCl and C–H silylation employing CuSCN/4,4′-dimethoxy-2,2′-bipyridine as catalyst can be performed without purification of the