Activation of 1,1-Difluoro-1-alkenes with a Transition-Metal Complex: Palladium(II)-Catalyzed Friedel–Crafts-Type Cyclization of 4,4-(Difluorohomoallyl)arenes
摘要:
Cationic palladium(II) ([Pd(MeCN)(4)](BF4)(2)) provides the first transition-metal-catalyzed method for electrophilic activation of electron-deficient 1,1-difluoro-1-alkenes, which allows their Friedel-Crafts-type cyclization with an intramolecular aryl group via a Wacker-type process. By using BF3 center dot OEt2, the cyclization was effected by a catalytic amount of the palladium without its reoxidation.
Monofluoroalkenylation of Dimethylamino Compounds through Radical–Radical Cross‐Coupling
作者:Jin Xie、Jintao Yu、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201602347
日期:2016.8
An unprecedented and challenging radical–radicalcross‐coupling of α‐aminoalkyl radicals with monofluoroalkenyl radicals derived from gem‐difluoroalkenes was achieved. This first example of tandem C(sp3)−H and C(sp2)−F bond functionalization through visible‐light photoredox catalysis offers a facile and flexible access to privileged tetrasubstituted monofluoroalkenes under very mild reaction conditions
Direct Difluoromethylenation of Carbonyl Compounds by Using TMSCF<sub>3</sub>: The Right Conditions
作者:Sankarganesh Krishnamoorthy、Jotheeswari Kothandaraman、Jacqueline Saldana、G. K. Surya Prakash
DOI:10.1002/ejoc.201601038
日期:2016.10
A deoxygenative difluoromethylenation of carbonylcompounds has been developed by using readily available, inexpensive trifluoromethyltrimethylsilane, LiI, and PPh3. The presence of the Li+ ion prevents the unproductive exhaustion of trifluoromethyltrimethylsilane (TMSCF3) by keeping the soluble free fluoride concentration in the reaction medium under control. The strategy of combining solvents to
Electrocatalysis-Enabled Stereoselective Synthesis of Monofluoroalkenes via Hydrodefluorination of <i>gem</i>-Difluoroakenes
作者:Xiaoying Wang、Jiaxi Cai、Haixia Song、Le Liu、Xin-Hua Duan、Mingyou Hu
DOI:10.1021/acs.orglett.4c00112
日期:2024.3.1
We report a simple and economical method to synthesize monofluoroalkenesvia the electrochemical hydrodefluorination of gem-difluoroalkenes. This reaction proceeds efficiently at room temperature, eliminating the requirement for a costly transition metal catalyst, ligand, and external reducing agent. The monofluoroalkene products can be obtained in medium to good yields and up to 99:1 E/Z selectivity
我们报告了一种通过宝石二氟烯烃的电化学加氢脱氟合成单氟烯烃的简单且经济的方法。该反应在室温下有效进行,无需昂贵的过渡金属催化剂、配体和外部还原剂。单氟烯烃产品的产率中等至良好, E / Z选择性高达 99:1。该反应很容易扩展到克级。
Burgess,D.A. et al., Australian Journal of Chemistry, 1976, vol. 29, p. 1435 - 1443
作者:Burgess,D.A. et al.
DOI:——
日期:——
Streamlined Electrochemical Dihalogenation (F, Cl, and Br) of gem‐Difluoroalkenes Using Hydrogen Halides as Reagents
作者:Xiaoying Wang、Rui Zhang、Jiaxi Cai、Xin Liu、Haixia Song、Le Liu、Xin‐Hua Duan、Mingyou Hu
DOI:10.1002/ejoc.202400351
日期:2024.8.5
We established a straightforward electrochemical dihalogenation (F, Cl, and Br) process for gem‐difluoroalkenes. This reaction exhibits a broad functional group tolerance and has been effectively utilized in the construction of complex molecules. The subsequent synthetic transformations of the products have highlighted the adaptable nature of the dihalogenated compounds, demonstrating their potential application in drug discovery and the investigation of innovative materials. The effective utilization of the dihalogenated product for 18F‐labeling represents a novel approach in generating highly potent 18F‐labeled tracers.