通过使用I 2或I 2 / H 3 PO 3体系,将各种烯烃和炔烃以良好的产率转化为相应的烷基碘和烯基碘。在存在I 2的情况下,可以在室温下于空气中使用H 2 O作为溶剂将炔烃二碘化。由于可以通过萃取获得纯产物,因此该方法还具有简单的后处理程序。此外,首次将无毒廉价的膦酸H 3 PO 3与烯烃和炔烃成功加氢碘化,为有机碘的合成提供了一种简单实用的方法。
Palladium-catalysed aminosulfonylation of aryl-, alkenyl- and heteroaryl halides: scope of the three-component synthesis of N-aminosulfonamides
作者:Edward J. Emmett、Charlotte S. Richards-Taylor、Bao Nguyen、Alfonso Garcia-Rubia、Barry R. Hayter、Michael C. Willis
DOI:10.1039/c2ob07034k
日期:——
By using DABCO·(SO2)2, DABSO, as a solid bench-stable SO2-equivalent, the palladium-catalysed aminosulfonylation of aryl-, alkenyl- and heteroaryl halides has been achieved. N,N-Dialkylhydrazines are employed as the N-nucleophiles and provide N-aminosulfonamides as the products in good to excellent yields. The reactions are operationally simple to perform, requiring only a slight excess of SO2 (1.2–2.2 equiv.), and tolerate a variety of substituents on the halide coupling partner. Variation of the hydrazine component is also demonstrated. The use of N,N-dibenzylhydrazine as the N-nucleophile delivers N-aminosulfonamide products that can be converted into the corresponding primary sulfonamides using a high-yielding, telescoped, deprotection sequence. The ability to employ hydrazine·SO2 complexes as both the N-nucleophile and SO2 source is also illustrated.
Pyridine-Catalyzed Radical Borylation of Aryl Halides
作者:Li Zhang、Lei Jiao
DOI:10.1021/jacs.6b11813
日期:2017.1.18
A pyridine-catalyzed transition-metal-free borylation reaction of haloarenes has been developed based on the selective cross-coupling of an aryl radical and a pyridine-stabilized boryl radical. Arylboronates were produced from haloarenes under mild conditions. This borylation reaction features a broad substrate scope, operational simplicity, and gram-scale synthetic ability.
Chiral Alkyl Amine Synthesis via Catalytic Enantioselective Hydroalkylation of Enecarbamates
作者:Deyun Qian、Srikrishna Bera、Xile Hu
DOI:10.1021/jacs.0c11630
日期:2021.2.3
Chiral alkyl amines are omnipresent as bioactive molecules and synthetic intermediates. The catalytic and enantioselective synthesis of alkyl amines from readily accessible precursors is challenging. Here we develop a nickel-catalyzed hydroalkylation method to assemble a wide range of chiral alkyl amines from enecarbamates (N-Cbz-protected enamines) and alkyl halides with high regio- and enantioselectivity
Efficient Trifluoromethylation of Activated and Non-Activated Alkenyl Halides by Using (Trifluoromethyl)trimethylsilane
作者:Andreas Hafner、Stefan Bräse
DOI:10.1002/adsc.201100528
日期:2011.11
An efficient method for the trifluoromethylation of halogenated double bonds by using in situ generated “trifluoromethyl copper” is described. Herein, the most common trifluoromethyl source, (trifluoromethyl)trimethylsilane, was converted selectively into “trifluoromethyl copper” by using copper iodide as copper source and potassium fluoride as promoter. In 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone
Cross-Coupling Reactions of Alkenyl Halides with 4-Benzyl-1,4- Dihydropyridines Associated with <i>E</i>
to <i>Z</i>
Isomerization under Nickel and Photoredox Catalysis
Cross‐coupling reactions of alkenyl halides with 4‐alkyl‐1,4‐dihydropyridines as alkylation reagents have been achieved by combination of nickel and photoredox catalysts. Alkenyl halides bearing alkyl and aryl substituents are available. Particularly, in the use of aryl‐substituted alkenyl halides, cross‐coupling reactions are associated with E to Z isomerization of alkenes. Thus, Z‐isomers of the