我们在此描述了在没有过渡金属催化剂的情况下使用格氏试剂对四取代偕二氟烯烃和三取代单氟烯烃进行选择性 C-F 键官能化。β,β-二氟丙烯酸酯与格氏试剂在温和条件下反应生成四取代 ( E )-β-单氟丙烯酸酯。实验和计算研究表明,选择性源于 ( E )- 和 ( Z )-异构体对过量格氏试剂的内在反应性差异,这导致两种产物的分离。
Regioselective Radical Hydroboration of <i>gem</i>-Difluoroalkenes: Synthesis of α-Borylated Organofluorines
作者:Ji-Kang Jin、Wan-Xin Zheng、Hui-Min Xia、Feng-Lian Zhang、Yi-Feng Wang
DOI:10.1021/acs.orglett.9b03173
日期:2019.10.18
hydroboration of gem-difluoroalkenes was developed for the synthesis of α-difluoroalkylborons. The reaction features excellent regioselectivity, broad substrate scope, and good functional group capability. DFT calculations implicated the remarkable α-selectivity was driven from the kinetically and thermodynamically more favorable α-addition step. The resulting α-difluoroalkylborons could be readily converted
Reaction of Diazo Compounds with Difluorocarbene: An Efficient Approach towards 1,1-Difluoroolefins
作者:Zhikun Zhang、Weizhi Yu、Chenggui Wu、Chengpeng Wang、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201509711
日期:2016.1.4
e difluoromethylenation of diazocompounds that proceeds under mild conditions has been developed and is based on the use of TMSCF2Br as the difluoromethylene source and tetrabutylammonium bromide (TBAB) as the promoter. The chemoselective formal carbene dimerization reaction is achieved owing to the electronic properties and the relative stability of the difluorocarbene intermediate.
A synthetic protocol for the expedient construction of 5‐methylene‐1H‐pyrrol‐2(5H)‐one derivatives through rhodium‐catalyzed [4+1] annulation with gem‐difluoroacrylate as the C1 component was reported. By taking advantage of the twofold C−F bond cleavage occurring during the annulation, this reaction not only allows the synthesis of these heterocyclic compounds under overall oxidant‐free conditions
A New Access to 3-Halo-3,3-difluoropropanoic Acid Derivatives via Fluorine–Halogen Exchange Reaction of Silyl Enolates of 3,3,3-Trifluoropropanoic Acid Derivatives
作者:Taichi Shimada、Tsutomu Konno、Takashi Ishihara
DOI:10.1246/cl.2007.636
日期:2007.5.5
On the treatment of silyl enolatesderivedfrom N-(3,3,3-trifluoropropanoyl)oxazolidinones with 2.0 equiv. of titanium(IV) halide at −20 °C for 2 h, a novel fluorine–halogen exchange reaction occur...
Stereoselective Palladium-Catalyzed Hiyama Cross-Coupling Reaction of Tetrasubstituted <i>gem</i>-Difluoroalkenes
作者:Min Li、Gavin Chit Tsui
DOI:10.1021/acs.orglett.3c04037
日期:2024.1.12
We herein describe a diastereoselective Pd(0)-catalyzed Hiyama cross-coupling reaction of gem-difluoroalkenes. The use of organosiliconreagents in this reaction is advantageous over other organometallic reagents by allowing the introduction of a wide range of functional groups, including challenging alkyl groups. Also conveniently, the additive TBAF was not required for (hetero)aryl-substituted difluoroalkenes