NHC–copper hydrides as chemoselective reducing agents: catalytic reduction of alkynes, alkyl triflates, and alkyl halides
作者:Nick Cox、Hester Dang、Aaron M. Whittaker、Gojko Lalic
DOI:10.1016/j.tet.2014.04.004
日期:2014.7
as well as the NHC–copper-catalyzed reduction of primary alkyl triflates and primary and secondary alkyl iodides and bromides are described. The high chemoselectivity demonstrated in these examples illustrates the mild nature of copper hydride complexes as reducing agents, which have applications in synthetic chemistry beyond their traditional role in the reduction of activated alkenes and carbonyl compounds
Regio- and Stereoselective Synthesis of 1,2-Dihaloalkenes Using In-Situ-Generated ICl, IBr, BrCl, I2, and Br2
作者:Xiaojun Zeng、Shiwen Liu、Yuhao Yang、Yi Yang、Gerald B. Hammond、Bo Xu
DOI:10.1016/j.chempr.2020.03.011
日期:2020.4
2-trans-dihalogenation of alkynes with an unprecedented substrate scope and exclusive regio- and stereoselectivity. This versatile dihalogenation system—a combination of NX1S electrophile and alkali metal halide (MX2) in acetic acid—is applicable for diverse categories of alkynes (electron-rich or poor alkynes, internal and terminalalkynes, or heteroatoms such as O-, N-, S-substituted alkynes). The hydrogen
我们描述了炔烃的无催化剂的1,2-反式二卤代反应,具有空前的底物范围和排他性和立体选择性。这种多功能的二卤化系统-NX 1 S亲电试剂和乙酸中的碱金属卤化物(MX 2)的组合-适用于各种类型的炔烃(富电子或弱炔烃,内部和末端炔烃,或杂原子,例如O- ,N-,S-取代的炔烃)。氢键供体溶剂乙酸对于就地生成X 1 X 2亲电试剂(包括ICl,IBr,BrCl,I 2和Br 2)是必不可少的。
Monophasic Catalytic System for the Selective Semireduction of Alkynes
作者:Aaron M Whittaker、Gojko Lalic
DOI:10.1021/ol4001679
日期:2013.3.1
A highly efficient semireduction of alkynes has been developed. Using 0.5–2 mol % of a copper catalyst, semireduction can be accomplished with a wide range of substrates, including both internal and terminal alkynes without over-reduction. The new method has excellent chemoselectivity, and the semireduction can be accomplished even in the presence of nitro and aryl iodo groups. Finally, commercial
Aryl Radical Enabled, Copper-Catalyzed Sonogashira-Type Cross-Coupling of Alkynes with Alkyl Iodides
作者:Xiaojun Zeng、Chao Wang、Wenhao Yan、Jian Rong、Yanshan Song、Zhiwei Xiao、Aijie Cai、Steven H. Liang、Wei Liu
DOI:10.1021/acscatal.2c05901
日期:2023.2.17
Despite the success of Sonogashira coupling for the synthesis of arylalkynes and conjugated enynes, the engagement of unactivated alkyl halides in such reactions remains historically challenging. We report herein a strategy that merges Cu-catalyzed alkyne transfer with the aryl radical activation of carbon–halide bonds to enable a general approach for the coupling of alkyl iodides with terminal alkynes