Intermolecular Hydrazinative Halogenation of Alkenes with Potassium Halides as Nucleophilic Halogen Sources: Modular Entry to Phenelzine Derivatives
Nan Huang, Lihao Liao and Xiaodan Zhao*
*School of Chemistry, Sun Yat-Sen University, Guangzhou, Guangdong 510006, P. R. China,
Email: zhaoxd3
mail.sysu.edu.cn
N. Huang, L. Liao, X. Zhao, Org. Lett., 2023, 25, 6587-6592.
DOI: 10.1021/acs.orglett.3c02475
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Abstract
An acid-mediated electrophilic hydrazinative halogenation of alkenes proceeds with readily available diethyl azodicarboxylate as a hydrazine source and low-cost potassium halides as nucleophilic halogen sources. A series of iodinated, brominated, and chlorinated hydrazines are facilely produced with a wide range of functional groups.
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proposed mechanism
General synthetic procedure
To a 10 mL vial equipped with a stir bar were added alkene (0.2 mmol, 1.0 equiv), DEAD (0.2 mmol, 1.0 equiv), KI (0.4 mmol, 2.0 equiv) and DCM (1.0 mL, 0.2 M). The mixture was cooled to 0°C, and then TfOH (0.3 mmol, 1.5 equiv) was added. The resulting mixture was stirred at 0°C. After 10 min, Na2S2O3 (2.0 M solution in H2O, 0.4 mmol, 2.0 equiv) was added. The mixture was stirred at 0 °C for 1 h. After the reaction was completed, the residue was directly purified by flash silica gel column chromatography (eluent: PE / EA = 10 : 1 to 5 : 1, v/v) to afford the desired product.
Key Words
hydrazine derivatives, benzyl iodides, multicomponent reactions
ID: J54-Y2023
