Palladium- and Ruthenium-Catalyzed Cycloisomerization of Enynamides and Enynhydrazides: A Rapid Approach to Diverse Azacyclic Frameworks
作者:P. Ross Walker、Craig D. Campbell、Abid Suleman、Greg Carr、Edward A. Anderson
DOI:10.1002/anie.201304186
日期:2013.8.26
I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high‐yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert‐butoxycarbonyl, EWG=electron‐withdrawing group, Ns=4‐nitrobenzenesulfonyl, Ts=4‐toluenesulfonyl
Engaging Sulfonamides: Intramolecular Cross-Electrophile Coupling Reaction of Sulfonamides with Alkyl Chlorides
作者:Erika L. Lucas、Kirsten A. Hewitt、Pan-Pan Chen、Anthony J. Castro、Xin Hong、Elizabeth R. Jarvo
DOI:10.1021/acs.joc.9b02603
日期:2020.2.21
The application of amine derivatives as coupling partners is rare due to the inherent strength of the C-N bond. Herein, we report the first cross-electrophile coupling reaction of unstrained benzylic sulfonamides. Nickel-catalyzed intramolecular cross-electrophile coupling reactions of acyclic and cyclic benzylic sulfonamides with pendant alkyl chlorides generate cyclopropane products. Mechanistic
Rh-Catalyzed Cycloisomerization of 1,7-Ene-Dienes to Synthesize <i>trans</i>-Divinylpiperidines: A Formal Intramolecular Addition Reaction of Allylic C–H Bond into Dienes
An originally designed Rh-catalyzed [4 + 2] cycloaddition reaction of nitrogen-tethered 1,7-ene-dienes turned out to be a cycloisomerization reaction, which involves allylic C-H activation/alkene insertion into Rh-H bond/reductive elimination processes. Deuterium labeling experiments gave support to the proposed mechanism. This unexpected cycloisomerization reaction provides an efficient way to synthesize
A range of unsaturated amines and sulfonamides were converted to β-fluoro nitrogen analogues after hydrofluorination in superacidHFâSbF5, based on the formation of highly reactive electrophilic intermediates.
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‐Prins Cyclization of Unfunctionalized Olefins Promoted by NHC‐Cu Complex and ZrCl
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作者:Yibo Jia、Lin Li、Lili Duan、Yue‐Ming Li
DOI:10.1002/aoc.5927
日期:2020.11
The aza‐Prinscyclization reaction catalyzed by ZrCl4 and NHC (N‐heterocyclic carbene) metal complexes is firstly reported. NHC‐copper complexes as promoter and ZrCl4 as chloride source are utilized under a mild condition, where homoallylic amines and aldehydes are successfully converted to piperidine derivatives in satisfactory yields and diastereoselectivity.