A widely used method to obtain tetrazoles is through the azide and nitrile [3+2] cycloaddition. However, this process often involves using non‐recyclable transition metals or Lewis acid catalysts and stoichiometric amounts of oxidants and additives, which reduces atom efficiency. We have discovered a convergent paired electrochemical reaction to perform this cycloaddition reaction, without the need for metal catalysts or oxidants. This tetrazolation strategy uses azidotrimethylsilane (TMSN3) and N‐heterocycles in an undivided cell at a constant current. We use a mixture of CH3CN and equivalent amounts of H2O as co‐solvent at room temperature. It is crucial to produce a stoichiometric amount of active hydroxyl ions through the cathodic reduction of water. Cyclic voltammetry (CV) studies and control experiments confirm that the cycloaddition reaction is specific to the electrode electron transfer process, eliminating the need for a mediator to shuttle electrons. This metal‐ and oxidant‐free strategy is highly compatible with different functional groups and produces products with moderate to good yields. We have successfully tetrazolated bioactive compounds at a late stage, scaled up batches efficiently, and synthesized free amino‐containing N‐heterocycles via denitrogenation of tetrazoles.
Photo-Induced Cross-Dehydrogenative Alkylation of Heteroarenes with Alkanes under Aerobic Conditions
作者:Jun Xu、Heng Cai、Jiabin Shen、Chao Shen、Jie Wu、Pengfei Zhang、Xiaogang Liu
DOI:10.1021/acs.joc.1c02125
日期:2021.12.17
We report a Minisci-type cross-dehydrogenative alkylation in an aerobic atmosphere using abundant and inexpensive cerium chloride as a photocatalyst and air as an oxidant. This photoreaction exhibits excellent tolerance to functional groups and is suitable for both heteroarene and alkane substrates under mild conditions, generating the corresponding products in moderate-to-good yields. Our method provides
Visible-light-induced C H arylation of quinoxalin-2(1H)-ones in H2O
作者:Hanyang Bao、Ziyun Lin、Mengshi Jin、Hongdou Zhang、Jun Xu、Bajin Chen、Wanmei Li
DOI:10.1016/j.tetlet.2021.152841
日期:2021.3
An efficient visible-light-induced CH arylation of quinoxalin-2(1H)-ones in H2O is developed, which has the advantages of mild reaction conditions, environmental friendliness and good functional group tolerance. This strategy provides a simple operation method to access various 3-aryl quinoxalin-2(1H)-ones in moderate to good yields.
Various 3‐alkoxylated quinoxalin‐2(1H)‐ones were synthesized in a simple undivided cell via electrochemically dehydrogenative C–H/O–H cross‐coupling between quinoxalin‐2(1H)‐ones and alcohols under mild conditions.
Direct C-H arylation of quinoxalinones with aryl acylperoxides under catalyst-free condition
作者:Bajin Chen、Shengpeng Wang、Jinxing Song、Xiaojun Wang、Bencheng Yu、Xiaobo Yang
DOI:10.1016/j.tetlet.2020.152681
日期:2021.1
A simple and novel method for the direct C-H arylation of quinoxalinones with aryl acylperoxides has been developed. This reaction proceeded smoothly through a radicalprocess under catalyst-free condition, giving the target products in moderate good yields. Such strategy provides a simple and green alternative for the synthesis of 3-arylquinoxalinones.