Hiyama coupling reaction of fluorous alkenyl-fluorosilanes: Scope and mechanistic considerations
摘要:
Novel fluorous alkenyl-fluorosilanes (CnF2n+1CH=CHSiMe2F; n = 4, 6, 8; 5a-c) were synthetized in a three step procedure from perfluoroalkyliodides and dimethylvinylchlorosilane. They were first reacted with iodobenzene at room temperature in Hiyama coupling reaction (DMF, Pd(OAc)(2), TBAF, 72 h) to afford the appropriate omega-perfluoroalkyl-styrenes (CnF2n+1CH=CHC6H5, n = 4, 6, 8): then the reactivity of 5a with monosubstituted iodobenzenes was studied. The coupling reaction of Sa with o-substituted iodobenzenes usually failed, while that of with the m- and p-substituted ones gave fluorous styrenes [m- or p-(C4F9CH=CH)C6H4X], independently of the electronic effect of their substituent (X = Br, CF3, CH3, OCH3). These volatile products can easily be isolated by steam-distilltaion and purified further by distillation. The mechanism of the above coupling reactions was a pure Hiyama type involving fluoride-ion induced transmetallation without any Heck type contribution, since no coupling product of C6F13CH=CH2 and C6H5I was observed in blank control experiments using similar conditions (DMF, TBAF, Pd(OAc)(2), 72 h, 25 degrees C). (c) 2012 Elsevier B.V. All rights reserved.
Fluoroalkenylation of boronic acids <i>via</i> an oxidative Heck reaction
作者:Da Seul Lee、Eun Jin Cho
DOI:10.1039/c9ob00332k
日期:——
A fluoroalkenylation of boronicacids with fluoroalkyl alkenes has been developed. The Pd-catalyzed oxidative Heck coupling reaction proceeds under an oxygen atmosphere at room temperature, in the absence of a base and/or a ligand, showing excellent practicality of the process. This simple transformation is highly stereoselective to provide only E-isomers. In addition to the general approach using
作者:Xiaolin Shi、Tao Song、Qinglin Li、Xiuling Guo、Yong Yang
DOI:10.1021/acs.orglett.2c03814
日期:2022.12.2
heterogeneous photocatalytic system for the switchable divergent perfluoroalkylation of terminalalkynes has been developed by employing mesoporous graphitic carbon nitride (mpg-CN) as a recyclable, nontoxic, and heavy-metal-free photocatalyst. Regulating the reaction solvents allowed libraries of perfluoroalkylated alkynes, alkenes, and alkenyl iodides to be synthesized in good-to-high yields. Furthermore