22332-65-6Relevant academic research and scientific papers
Gold N-Heterocyclic Carbene Catalysts for the Hydrofluorination of Alkynes Using Hydrofluoric Acid: Reaction Scope, Mechanistic Studies and the Tracking of Elusive Intermediates
Bédard, Sandrine,Cavallo, Luigi,Falivene, Laura,Gauthier, Rapha?l,Nolan, Steven P.,Paquin, Jean-Fran?ois,Saab, Marina,Tzouras, Nikolaos V.,Van Hecke, Kristof,Zhang, Ziyun
, (2021/12/09)
An efficient and chemoselective methodology deploying gold-N-heterocyclic carbene (NHC) complexes as catalysts in the hydrofluorination of terminal alkynes using aqueous HF has been developed. Mechanistic studies shed light on an in situ generated catalyst, formed by the reaction of Br?nsted basic gold pre-catalysts with HF in water, which exhibits the highest reactivity and chemoselectivity. The catalytic system has a wide alkyl substituted-substrate scope, and stoichiometric as well as catalytic reactions with tailor-designed gold pre-catalysts enable the identification of various gold species involved along the catalytic cycle. Computational studies aid in understanding the chemoselectivity observed through examination of key mechanistic steps for phosphine- and NHC-coordinated gold species bearing the triflate counterion and the elusive key complex bearing a bifluoride counterion.
Synthesis and Horner-Wittig Chemistry of (Fluoromethyl)diphenylphosphane Oxide
Steenis, Jan Hein van,Gen, Arne van der
, p. 897 - 910 (2007/10/03)
(Fluoromethyl)diphenylphosphane oxide (1) was obtained by heating (diphenylphosphinoyl)methyl p-toluenesulfinate (2) with potassium fluoride. Compound 1 is a stable, crystalline solid, suitable for application in the Horner-Wittig reaction. The compound described in the literature under this name was found to be benzylphenylphosphinic fluoride (5). The anion of phosphane oxide 1 readily reacted with a wide range of carbonyl to yield diastereomeric mixtures of α-fluoro-β-(hydroxyalkyl)phosphane oxides (7), which in most cases could be separated. The ease of phosphinate elimination to yield (E)- and (Z)-1-fluoroalkenes 8 stereoselectively was found to be strongly dependent upon conformation and substituent patern. The route presented here avoids the use of hazardous fluorohalomethanes, which were employed in several earlier Wittig-related approaches to vinyl fluorides.
