671-18-1Relevant academic research and scientific papers
Reversible C-F bond formation and the Au-catalyzed hydrofluorination of alkynes
Akana, Jennifer A.,Bhattacharyya, Koyel X.,Mueller, Peter,Sadighi, Joseph P.
, p. 7736 - 7737 (2007)
The gold(I) fluoride complex [(SIPr)AuF] [SIPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene] reacts reversibly with 3-hexyne to form a (β-fluorovinyl)gold(I) species. The more stable fluorovinyl complex trans-{(SIPr)Au[(Ph)C=C(F)CH3]}, formed by addition of [(SIPr)AuF] across 1-phenyl-1-propyne, has been characterized crystallographically. Both the protonolysis of a (fluorovinyl)gold complex and the reaction of a cationic (alkyne)gold(I) complex with the mild HF source Et3N?3HF result in fluoroalkene formation. Electrophilic gold(I) complexes, supported by N-heterocyclic carbene ligands and generated in situ, catalyze the trans-hydrofluorination of internal alkynes at room temperature. This catalysis represents a new, selective, and potentially versatile method for the synthesis of fluoroalkenes. Copyright
Divergent reactivities in fluoronation of allylic alcohols: Synthesis of: Z -fluoroalkenes via carbon-carbon bond cleavage
Liu, Tang-Lin,Wu, Ji'En,Zhao, Yu
, p. 3885 - 3890 (2017)
An unconventional cleavage of an unstrained carbon-carbon bond in allylic alcohols can be induced by the use of N-fluorobenzenesulfonimide (NFSI) under catalyst-free conditions. By using this simple procedure, a wide range of functionalized Z-fluoroalkenes can be accessed in high yield and selectivity from cyclic and acyclic allylic alcohols.
Convergent Synthesis of Fluoroalkenes Using a Dual-Reactive Unit
Isoda, Motoyuki,Uetake, Yuta,Takimoto, Tadashi,Tsuda, Junpei,Hosoya, Takamitsu,Niwa, Takashi
supporting information, p. 1622 - 1632 (2021/02/05)
Fluoroalkenes have shown importance as a metabolically stable isostere of amide compounds. To expedite the synthesis of diverse fluoroalkenes, we have developed a dual-reactive C2-unit, (Z)-1-boryl-1-fluoro-2-tosyloxyethene, containing nucleophilic and electrophilic moieties. Consecutive palladium-catalyzed cross-coupling reactions of this unit with aryl bromides and aryl boronic acids allow for the convergent synthesis of diverse trans-1,2-diaryl-substituted fluoroethenes in a chemoselective and stereoretentive manner.
Stereodivergent Alkyne Hydrofluorination Using Protic Tetrafluoroborates as Tunable Reagents
Geaneotes, Paul,Guo, Rui,Liu, Peng,Qi, Xiaotian,Wang, Ruihan,Wang, Yi-Ming,Xiang, Hengye
supporting information, p. 16651 - 16660 (2020/07/16)
The discovery of safe, general, and practical procedures to prepare vinyl fluorides from readily available precursors remains a synthetic challenge. The metal-free hydrofluorination of alkynes constitutes an attractive though elusive strategy for their preparation. Introduced here is an inexpensive and easily handled reagent that enables the development of simple and scalable protocols for the regioselective hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These reaction conditions were suitable for a diverse collection of alkynes, including several highly functionalized pharmaceutical derivatives. Computational and experimental mechanistic studies support C?F bond formation through vinyl cation intermediates, with the E- and Z-hydrofluorination products forming under kinetic and thermodynamic control, respectively.
Silver-Mediated Decarboxylative Fluorodiiodination of Alkynoic Acids: Synthesis of Regio- and Stereoselective Fluoroalkenes
Jayaraman, Aravindan,Lee, Sunwoo
, p. 3485 - 3489 (2019/05/24)
A variety of arylalkynoic acids reacted with 1,3-diiodo-5,5-dimethylhydantoin and HF·pyridine in the presence of AgOAc to provide the corresponding 1-fluoro-2,2-diiodovinylarenes in good yields and high regioselectivity. In addition, Pd-catalyzed cross-co
Selective Monodefluorination and Wittig Functionalization of gem-Difluoromethyl Groups to Generate Monofluoroalkenes
Mandal, Dipendu,Gupta, Richa,Young, Rowan D.
supporting information, p. 10682 - 10686 (2018/09/10)
Monodefluorination of gem-difluoromethyl groups is achieved using a frustrated Lewis pair (FLP) approach. Triarylphosphines and group 13 Lewis acids were surveyed as FLP components, with the combination of P(o-Tol)3 and B(C6F5)3 found to provide the best results, although the reaction is feasible with more economical components (PPh3 and BF3·OEt2). The α-fluoroalkylphosphonium products arising from the reaction were of lower activity, in regard to further fluoride abstraction, as compared to difluoride starting materials, leading to highly selective monodefluorination. The activated substrates were subject to Wittig reaction protocols to generate a variety of monofluoroalkenes in moderate to high yields.
Geminal difunctionalization of α-diazo arylmethylphosphonates: Synthesis of fluorinated phosphonates
Zhou, Yujing,Zhang, Yan,Wang, Jianbo
, p. 10444 - 10453 (2016/11/18)
A general approach towards diverse fluorinated phosphonates via geminal difunctionalization reactions of α-diazo arylmethylphosphonates is described. The diazo functionality (RR′CN2) is successfully converted to RR′CF2, RR′CHF, RR′CFBr or RR′CFNR′′2 groups by employing different fluorination reagents. A variety of fluorinated organophosphorus compounds were readily accessed in good to excellent yields from a common type of precursor.
Hydrofluorination of alkynes catalysed by gold bifluorides
Nahra, Fady,Patrick, Scott R.,Bello, Davide,Brill, Marcel,Obled, Alan,Cordes, David B.,Slawin, Alexandra M. Z.,O'Hagan, David,Nolan, Steven P.
, p. 240 - 244 (2015/03/03)
We report the synthesis of nine new N-heterocyclic carbene gold bifluoride complexes starting from the corresponding N-heterocyclic carbene gold hydroxides. A new methodology to access N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) fluoride starting from N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) hydroxide and readily available potassium bifluoride is also reported. These gold bifluorides were shown to be efficient catalysts in the hydrofluorination of symmetrical and unsymmetrical alkynes, thus affording fluorinated stilbene analogues and fluorovinyl thioethers in good to excellent yields with high stereo- and regioselectivity. The method is exploited further to access a fluorinated combretastatin analogue selectively in two steps starting from commercially available reagents.
Reactivity of platinum alkyne complexes towards N-fluorobenzenesulfonimide: formation of platinum compounds bearing a β-fluorovinyl ligand
Berger, Josefine,Braun, Thomas,Herrmann, Roy,Braun, Beatrice
, p. 19553 - 19565 (2015/11/27)
The platinum(0) alkyne complexes [Pt(L)(η2-PhC≡CPh)] 1-4 were synthesized by reactions of [Pt(cod)2] with diphenylacetylene and a phosphine ligand precursor (1: L = dcpe, 2: L = xantphos, 3: L = κ2-(P,N)-iPr2PC
Regioselective Synthesis of Vinyl Halides, Vinyl Sulfones, and Alkynes: A Tandem Intermolecular Nucleophilic and Electrophilic Vinylation of Tosylhydrazones
Ojha, Devi Prasan,Prabhu, Kandikere Ramaiah
, p. 18 - 21 (2015/07/28)
A diazo species is trapped in an intermolecular fashion by two independent ion species in tandem at the carbene center to install an electrophile and a nucleophile on the same carbon. This metal-free concept, which is unprecedented, has been illustrated by regioselective synthesis of a variety of vinyl halides, vinyl sulfones, and alkyne derivatives. (Chemical Equation Presented).
