1,1-dibromo-2,2-difluoroethylene and n-butyllithium, with aldehydes or ketones, and subsequent acetylation, gives 2-bromo-3,3-difluoroallylic acetates. Elimination of these acetates with n-butyllithium affords 1,1-difluoroallenes in high yield. 3,3-Difluoro-2-iodoallylic acetates are similarly prepared from aldehydes or ketones on treatment with 2,2-difluoro-1-iodovinyllithium, generated from 1,1,
The synthesis of stereo-defined α-trifluoromethyl arylenes is of great importance in medical chemistry, organic chemistry, and materials science. However, despite the recent advances, the Z-selective formation of α-trifluoromethyl arylenes has remained underdeveloped. Here, we describe a facile approach towards Z-α-trifluoromethyl arylenes through Pd-catalysed stereoselective fluoroarylation of 1,1-difluoroallenes
Copper-Catalyzed Protoarylation of <i>gem</i>-Difluoroallenes
作者:Wei Li、Cheng Wang、Mengdie Xiao、Li-Jie Cheng
DOI:10.1021/acs.orglett.3c03995
日期:2024.1.19
A copper-catalyzed protoarylation of gem-difluoroallenes with aryl boronic esters has been developed, enabling highly regioselective synthesis of gem-difluoroalkenes in high yields. The mild reaction conditions allow for a variety of functional groups to be tolerated, and the reaction can be extended to protoalkenylation of gem-difluoroallenes. The synthetic utility of this method has been demonstrated
In this study, 1,1-difluoroallenes underwent a regioselective [2+3] cycloaddition with nitrile oxides and imine oxides in the presence of a AuCl catalyst. (E)-4-Alkylidene-5,5-difluoroisoxazolines and -isoxazolidines were obtained in regioselective and diastereoselective manners by employing aurated difluoroallylic cation intermediates. The synthesized 5,5-difluoroisoxazolines were readily aromatized
在这项研究中,1,1-二氟丙二烯在 AuCl 催化剂存在下与氧化腈和氧化亚胺发生区域选择性 [2+3] 环加成反应。( E )-4-亚烷基-5,5-二氟异恶唑啉和5,5-二氟异恶唑烷是通过使用含金二氟烯丙基阳离子中间体以区域选择性和非对映选择性方式获得的。合成的 5,5-二氟异恶唑啉很容易通过脱氟化氢或烯丙基氟取代来芳构化,得到 5-氟异恶唑。