可见光催化烷基磺酰自由基启动芳酰肼的烷基磺酰化反应  

Visible-light Photocatalytic Alkylsulfonylation of Aroylhydrazides with Alkylsulfonyl Radicals

作　　者：杨民 叶柏柏 陈健强 吴劼 Yang Min;Ye Baibai;Chen Jianqiang;Wu Jie(School of Pharmaceutical and Materials Engineering,Taizhou University,Taizhou 318000,China;Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases,Ministry of Education,Gannan Medical University,Ganzhou 341000,China)

机构地区：[1]台州学院医药化工与材料工程学院,台州318000 [2]赣南医学院心脑血管疾病防治教育部重点实验室,赣州341000

出　　处：《化学学报》2022年第1期11-15,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.21871053,22007017)资助。

摘　　要：鉴于磺酰基在有机分子中的重要意义,磺酰基的引入与磺酰化合物的合成被广泛报道.其中,磺酰肼化合物因在抗肿瘤、抗菌等方面表现出的生物活性,其相关合成备受关注.本工作发展了可见光照射下烷基三氟硼酸钾、DABCO·(SO_(2))_(2)(1,4-Diazabicyclo[2.2.2]octane,DABCO)和芳酰肼的有机光反应,一锅法获得了中等到良好收率的N'-酰基-N-磺酰肼化合物,该反应底物适用性广、绿色温和.机理研究表明该反应经历自由基反应历程,即由烷基三氟硼酸钾在光催化作用下原位生成的烷基自由基引发的,随后通过二氧化硫插入形成烷基磺酰基自由基中间体,最后被芳酰肼氧化产生的N-酰基二氮烯中间体捕获,从而生成N'-酰基-N-磺酰化产物.In view of the importance of sulfonyl groups in organic molecules, the introduction of sulfonyl groups and the synthesis of sulfonyl compounds have been widely reported. Among them, the synthesis of sulfonylhydrazides has attracted much attention because of their biological activities in antitumor and antibacterial activities. Here, we developed a photoinduced reaction of potassium alkyltrifluoroborates, DABCO·(SO_(2))_(2)(1,4-Diazabicyclo[2.2.2]octane, DABCO), and aroylhydrazides under visible light irradiation, which obtained N’-acyl-N-alkylsulfonylhydrazides in moderate to good yields in one-pot. This reaction works in a green and mild way with a broad substrate scope. Mechanistic study shows that after giving rise to N-acyldiazenes via the oxidation of aroylhydrazides, the transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates in the presence of photocatalyst. The subsequent insertion of sulfur dioxide and alkylsulfonylation of N-acyldiazenes with alkylsulfonyl radical intermediates afford the corresponding N’-acyl-N-alkylsulfonylhydrazides. General procedure for visible-light photocatalytic alkylsulfonylation of aroylhydrazides with alkylsulfonyl radicals: to a solution of aroylhydrazides 1(0.2 mmol) and K;CO;(0.3 mmol) in MeCN(2.0 mL) was added I;(0.12 mmol). The reaction was stirred for h at room temperature, then quenched with sat. aq. Na;S;O;(15 mL). The layers were separated and the aqueous layer extracted with dichloromethane(DCM)(15 mL×3). The combined organic layers were then washed with brine(15 mL), and dried over Na;SO;. Evaporation of the solvent under reduced pressure afforded the crude N-acyldiazenes,which was used in the subsequent transformation without further purification. The crude N-acyldiazenes were combined with potassium alkyltrifluoroborates 2(0.24 mmol), DABCO·(SO_(2))_(2)(0.2 mmol) and 9-mesityl-10-methylacridinium perchlorate([Mes-Acr]ClO;)(0.004 mmol) in a tube. The tube was evacuated and backfilled with N;three times before the

关 键 词：可见光催化 磺酰化 烷基磺酰基自由基 N-酰基二氮烯 磺酰肼 

分 类 号：O621.251[理学—有机化学]