The preparation and cycloaddition reaction of 1-sulfonyl-1-trifluoromethyl allenes
作者:Jun-Li Li、Xian-Jin Yang、Min Jiang、Jin-Tao Liu
DOI:10.1016/j.tetlet.2017.07.050
日期:2017.8
A series of 1-sulfonyl-1-trifluoromethyl allenes were prepared for the first time from commercial available 2-bromo-3,3,3-trifluoropropene. Cycloadditionreaction of these trifluoromethylated allenes with nitrones occured readily under mild conditions, giving the corresponding trifluoromethylated isoxazolidines in high yields.
Practical Synthesis of
<i>α</i>
‐Trifluoromethylated Pyridines Based on Regioselective Cobalt‐Catalyzed [2+2+2] Cycloaddition using Trifluoromethylated Diynes with Nitriles
作者:Tatsuya Kumon、Shigeyuki Yamada、Tomohiro Agou、Hiroki Fukumoto、Toshio Kubota、Gerald B. Hammond、Tsutomu Konno
DOI:10.1002/adsc.202001433
日期:2021.3.29
Regioselective cobalt‐catalyzed [2+2+2] cycloaddition using fluorine‐containing diynes with nitriles was described. Cycloaddition of fluorinated diynes with nitriles under the influence of CoCl2(phen), zinc bromide, and zinc dust in dichloroethane at 80 °C for 3 h took place smoothly, exclusively affording the corresponding α‐fluoroalkylated pyridines in excellent yields. In addition, dinitriles as
描述了使用含氟二炔与腈进行区域选择性钴催化的[2+2+2]环加成反应。在 CoCl 2 (phen)、溴化锌和锌粉的影响下,氟化二炔与腈在二氯乙烷中在 80 °C 下环加成 3 小时,顺利进行,以优异的收率专门提供了相应的α-氟烷基化吡啶。此外,二腈作为底物也被发现适合该反应,以优异的收率得到相应的氟烷基化联吡啶衍生物。
Preparation of CF<sub>3</sub>-Containing 1,3-Di- and 1,1,3-Trisubstituted Allenes
Novel synthetic pathway to access trifluoromethylated allenes with 1,3-di- as well as 1,1,3-trisubstitution patterns was developed from a variety of 4,4,4-trifluorobut-2-yn-1-ols which were then transformed into the corresponding vinylic iodides in highly regio- and stereospecific manners, and zinc-mediated β-elimination after trifluoroacetylation of the hydroxyl group eventually realized the formation
Treatment of various fluorinated internal alkynes with 10 mol% of RhCl3·H2O and 30 mol% of i-Pr2NEt in toluene at the reflux temperature for 18 h gave the corresponding trimerization products as an isomeric mixture in high yields. Cycloaddition using 1.0 equiv. of fluorinated alkynes and 2.0 equiv. of non-fluorinated alkynes under the same reaction conditions as in the trimerization led to mono- and
A novel method for the generation of 3,3,3-trifluoro-propynyllithium is reported, which involves treatment of trifluoromethyl-substituted enol tosylate, prepared from 1,1-dichloro-3,3,3-trifluoroacetone, with two equivalents of butyllithium. -Palladium-catalyzed coupling reaction of sulfonates of the carbonyl adducts with organozinc reagents gave trifluoromethyl-containing tri- and tetrasubstituted