Chemo-, regio- and stereoselective synthesis of monofluoroalkenes <i>via</i> a tandem fluorination–desulfonation sequence
作者:Ren-Yin Yang、Bo Xu
DOI:10.1039/d1cc03207k
日期:——
approach for the synthesis of Z-monofluoroalkenes from readily available alkyl triflones and NFSI has been reported. The reaction proceeded under mild conditions, affording mono-fluorinated alkenes in good to excellent yields with excellent chemo- regio- and stereoselectivity. The mechanism may involve electrophilic fluorination of triflones followed by the highly stereoselective concerted bimolecular
已经报道了一种从容易获得的烷基三氟乙烯和 NFSI合成Z-单氟烯烃的广泛适用的方法。该反应在温和的条件下进行,以良好的收率和优异的化学区域选择性和立体选择性提供单氟化烯烃。该机制可能涉及三氟酮的亲电氟化,然后是 CF 3 SO 2 H的高度立体选择性协同双分子消除 (E2) 。
Synthesis of ArCF<sub>2</sub>X and [<sup>18</sup>F]Ar-CF<sub>3</sub> via Cleavage of the Trifluoromethylsulfonyl Group
A versatile synthesis of ArCF2X and [18F]Ar-CF3 type compounds from readily available ArCF2SO2CF3 has been developed. Diverse nucleophiles, including weak nucleophiles such as halides (18F–, Cl–, Br–, and I–), RSH, and ROH, could react with ArCF2SO2CF3 efficiently to give the corresponding difluoromethylene products. The control experiments and the Hammett plot indicated that the reaction might proceed
已经开发了一种从容易获得的 ArCF 2 SO 2 CF 3合成 ArCF 2 X 和 [ 18 F]Ar-CF 3型化合物的通用方法。多种亲核试剂,包括弱亲核试剂,如卤化物(18 F –、Cl –、Br –和 I –)、RSH 和 ROH,可以与 ArCF 2 SO 2 CF 3反应有效地得到相应的二氟亚甲基产物。对照实验和哈米特图表明,反应可能通过三氟甲基磺酰基的空间位阻辅助裂解产生的二氟碳正离子中间体进行。
Facile Synthesis of Aryl- and Alkyl-bis(trifluoromethylsulfonyl)methanes
Various arylbis(trifluoromethylsulfonyl)methanes (1) have been synthesized by reacting the corresponding benzylic halides with sodium trifluoromethanesulfinate and then with triflic anhydride. In addition, when the aryl group of 1 is a pentafluorophenyl group, the nucleophilic para-substitution of the aryl group with alkyllithiums and sodium alkoxides occurs. This reaction is useful for the design of new Brønsted acids.
A two-step synthesis of benzylic triflones, based on the reaction of 2,4,6-trisubstituted phenyl halides 3a-f with the anion of ethyl (trifluoromethanesulfonyl)acetate 1 followed by a decarboxylation reaction, is reported. The structural assignments are supported by spectroscopic data.
A new approach toward the synthesis of aryl triflones was achieved by the formalinsertion of arynes into C–SO2CF3 bonds. This reaction proceeds through addition of CF3SO2-containing nucleophiles to the in situ generated arynes and subsequent intramolecular rearrangement.
通过将芳烃正式插入C–SO 2 CF 3键中,实现了一种新的芳基三氟酮合成方法。该反应通过将含CF 3 SO 2的亲核试剂添加到原位生成的芳烃中并随后进行分子内重排而进行。