acetylenes bearing a variety of substituents with perfluoroalkyl iodides in the presence of a catalytic amount of triethylborane provides the corresponding perfluoroalkenes in good to excellent yields. The addition of perfluoroalkyl iodides to olefins is also described.
Iron-Catalyzed 1,2-Addition of Perfluoroalkyl Iodides to Alkynes and Alkenes
作者:Tao Xu、Chi Wai Cheung、Xile Hu
DOI:10.1002/anie.201402511
日期:2014.5.5
Iron catalysis has been developed for the intermolecular 1,2‐addition of perfluoroalkyliodides to alkynes and alkenes. The catalysis has a wide substrate scope and high functional‐group tolerance. A variety of perfluoroalkyliodides including CF3I can be employed. The resulting perfluoroalkylated alkyl and alkenyl iodides can be further functionalized by cross‐coupling reactions. This methodology
Controlled Trifluoromethylation Reactions of Alkynes through Visible-Light Photoredox Catalysis
作者:Naeem Iqbal、Jaehun Jung、Sehyun Park、Eun Jin Cho
DOI:10.1002/anie.201308735
日期:2014.1.7
The control of a reaction that can form multiple products is a highly attractive and challenging concept in synthetic chemistry. A set of valuable CF3‐containing molecules, namely trifluoromethylated alkenyl iodides, alkenes, and alkynes, were selectively generated from alkynes and CF3I by environmentally benign and efficient visible‐light photoredoxcatalysis. Subtle differences in the combination
Treatment of per- or polyfluoroalkylated vinyl iodides 5 with 2 equiv. of n-BuLi in THF produced the corresponding lithium acetylides in situ, which were transformed into zinc acetylides by the addition of ZnCl2.TMEDA complex into the reaction mixture. The in situ generated zinc acetylides were exposed to the cross-coupling conditions such as ArI/cat. Pd(PPh3)(4), reflux, 6-12 h, giving rise to the desired per- or polyfluoroalkylated acetylenes in high yields. In the case of trifluoromethylated acetylene, commercially available 2-bromo-3,3,3-trifluoropropene 6 could also be used instead of 5 as the starting material. In the acetylenes having a fluoroalkyl group and an aliphatic side chain, vinyl iodides 7, prepared by radical addition of perfluoroalkyl iodide to terminal acetylenes, were treated with t-BuOK at room temperature or at the reflux temperature of benzene, affording the desired compounds in good yields. (C) 2003 Elsevier Ltd. All rights reserved.