Construction of <i>N</i>-Alkyl- and <i>N</i>-Arylaziridines from Unprotected Amines via C–H Oxidative Amination Strategy
作者:Yang Yu、Meijuan Li、Yong Zhang、Yonghai Liu、Lei Shi、Wei Wang、Hao Li
DOI:10.1021/acs.orglett.8b03799
日期:2019.2.15
A copper-promoted intramolecular C–H oxidative amination reaction between secondary amine (N–H) and C(sp3)–H at the benzylic position of azaarenes or α-position of ketones for the synthesis of aziridine derivatives has been developed. Moreover, a practical annulation of electron-deficient vinylarenes with an unprotected primary alkyl amine by a Yb(OTf)3–CuI relay system has also been reported. The
Visible light induced photoredox catalysis is an efficient method for radical activation. Herein, we report a photoredox catalyzed intramolecular radical-radical coupling reaction that proceeds through biradical intermediate. This protocol represents...
Utility of Ketonic Mannich Bases in Synthesis of Some New Functionalized 2-Pyrazolines
作者:Elsayed M. Afsah、Eman M. Keshk、Abdel-Rahman H. Abdel-Rahman、Najla F. Jomah
DOI:10.1002/jhet.3055
日期:2018.1
piperazine to give 13. N‐Nitrosation of the sec‐Mannichbases 15a–d followed by reductive cyclization affords 2‐pyrazolines 17a–d. The keto base 14b has been used for the synthesis of 2‐pyrazolines having a phenolic Mannich base at C‐3 and its reaction with 3,5‐dimethyl‐1H‐pyrazole affords 23. The alkylation of 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one with the bis(Mannich base) 25 was investigated.
An operationally simple, inexpensive, efficient, and environmentally friendly protocol for the amineexchangereactions of 3-N,N-dimethylaminopropiophenone and N,N-dimethylaminomethylferrocene with primary aryl amines is developed using the ionic liquid [bmim]PF 6 as a solvent. The recovered ionic liquid can be reused for several cycles with constant activity.
Divergent Synthesis of Multisubstituted Tetrahydrofurans and Pyrrolidines via Intramolecular Aldol‐type Trapping of Onium Ylide Intermediates
作者:Changcheng Jing、Dong Xing、Lixin Gao、Jia Li、Wenhao Hu
DOI:10.1002/chem.201503621
日期:2015.12.21
divergent strategy for the synthesis of multisubstituted tetrahydrofurans and pyrrolidines, starting from easily accessible β‐hydroxyketones or β‐aminoketones to react with diazo compounds. Under RhII catalysis, this transformation is proposed to proceed through a metal–carbene‐induced oxonium ylide or ammonium ylide formation followed by an intramolecular aldol‐type trapping of these active intermediates