一种新型瞬态 SET 介体方法已被开发用于光诱导自由基-自由基交叉偶联反应。利用原位产生的噻蒽自由基阳离子作为瞬态SET介体,在温和条件下实现了芳基噻蒽鎓盐的硫氰化和硒氰化,无需光催化剂或单一电子给体。与光触媒工艺相比,该方案具有条件温和、操作简单、底物范围广泛、优异的官能团和杂环耐受性等特点。由于芳基噻啉鎓盐的可行可及性,该方法也已应用于生物活性分子的有效合成以及复杂芳烃的后期功能化。
halogenated cycloadducts via cyanation using copper and SNArreaction provides substituted selenopyridines with good yields. A novel synthetic method for the preparation of selenopyridine derivatives, involving a [2+2+2] cycloaddition of α,ω-diynes and selenocyanates that is catalyzed by a ruthenium complex is described. This mild and straightforward reaction allows access to a wide range of selenopyridines
作为有机合成中的特殊主题钌的一部分出版 抽象的 描述了一种制备硒吡啶吡啶衍生物的新颖合成方法,该方法涉及由钌配合物催化的α,ω-二炔和硒氰酸酯的[2 + 2 + 2]环加成。使用二氯甲烷或二氯乙烷作为溶剂,在50或80°C下,这种温和而直接的反应可以以高收率和优异的区域选择性获得各种硒吡啶。使用铜和S N Ar反应通过氰化作用将卤代环加合物进行后官能化,可提供具有良好收率的取代硒基吡啶。 描述了一种制备硒吡啶吡啶衍生物的新颖合成方法,该方法涉及由钌配合物催化的α,ω-二炔和硒氰酸酯的[2 + 2 + 2]环加成。使用二氯甲烷或二氯乙烷作为溶剂,在50或80°C下,这种温和而直接的反应可以以高收率和优异的区域选择性获得各种硒吡啶。使用铜和S N Ar反应通过氰化作用将卤代环加合物进行后官能化,可提供具有良好收率的取代硒基吡啶。
Metal‐Free Synthesis of Aryl Selenocyanates and Selenaheterocycles with Elemental Selenium
This work reports a green method for the synthesis of aryl selenocyanates via a three‐component reaction of arylboronicacids, Se powder, and trimethylsilyl cyanide (TMSCN) undermetal‐free and additive‐freeconditions. Remarkably, TMSCN acts as not only the substrate, but also the catalyst. Various selenaheterocycles can be also accessed with a catalytic amount of TMSCN.
Synthesis of Monofluoromethyl Selenoethers of Aryl and Alkyl from Organoselenocyanate via One‐Pot Reaction
作者:Yuan Cao、Lvqi Jiang、Wenbin Yi
DOI:10.1002/adsc.201900480
日期:2019.9.17
approach for the monofluoromethylselenolation of aryl and alkyl halides via one‐pot multistep synthesis using KSeCN and ICFH2 is described. Good yields and broad functional group compatibility were obtained. The successful preparation of monofluoromethylselenolated drug‐like compounds good practicability of this method. This protocol offered a number of new monofluoromethyl selenoethers, which would accelerate
intermediates. The first ipso-selenocyanation of arylboronicacids is achieved using selenium dioxide and malononitrile under mild conditions. The reaction is successful even without metal or base in DMSO. The major advantages of this new method are an easy set-up, excellent yields, and the use of odorless and inexpensive selenium reagents. Basic conditions subsequently afford new access to diaryldiselenides
Transition-Metal-Free HFIP-Mediated Organo Chalcogenylation of Arenes/Indoles with Thio-/Selenocyanates
作者:Pratibha Kalaramna、Avijit Goswami
DOI:10.1021/acs.joc.1c00478
日期:2021.7.16
developed a protocol for the synthesis of diaryl thio-/selenoethers by the reaction of aryl chalcogenocyanates with electron rich arenes/hetero arenes via HFIP promoted C–H activation. The reaction produces chalcogenides in good to excellent yields undermildconditions without the need of a transition metal as a catalyst. The HFIP-mediated reactions tolerated a wide range of functional groups and set the stage