120776-55-8Relevant academic research and scientific papers
Triplet acetylenes as synthetic equivalents of 1,2-bicarbenes: Phantom n,π* state controls reactivity in triplet photocycloaddition
Zeidan, Tarek A.,Kovalenko, Serguei V.,Manoharan, Mariappan,Clark, Ronald J.,Ghiviriga, Ion,Alabugin, Igor V.
, p. 4270 - 4285 (2005)
Diaryl acetylenes, in which one of the aryl groups is either a pyridine or a pyrazine, undergo efficient triplet state photocycloaddition to 1,4-cyclohexadiene with formation of 1,5-diaryl substituted tetracyclo[3.3.0. 02,8.04,6]octa
Synthesis, optical properties, crystal structures and phase behaviour of selectively fluorinated 1,4-bis(4′-pyridylethynyl)benzenes, 4-(phenylethynyl)pyridines and 9,10-bis(4′-pyridylethynyl)-anthracene, and a Zn(NO3)2 coordination polymer
Fasina, Tolulope M.,Collings, Jonathan C.,Lydon, Donocadh P.,Albesa-Jove, David,Batsanov, Andrei S.,Howard, Judith A. K.,Nguyen, Paul,Bruce, Mitch,Scott, Andrew J.,Clegg, William,Watt, Stephen W.,Viney, Christopher,Marder, Todd B.
, p. 2395 - 2404 (2004)
A series of selectively fluorinated and non-fluorinated rigid rods based on the 4-pyridylethynyl group, namely 1,4-bis(4′-pyridylethynyl)benzene (1a), 1,4-bis(4′-pyridylethynyl)tetrafluorobenzene (1b), 1,4-bis(2′,3′,5′,6′-tetrafluoropyridylethynyl)benzene (1c), 1,4-bis(2′,3′,5′,6′-tetrafluoropyridylethynyl) tetrafluorobenzene (1d), 9,10-bis(4′-pyridylethynyl)anthracene (2), 4-(pentafluorophenylethynyl)pyridine (3a) and 4-(phenylethynyl)- tetrafluoropyridine (3b) were prepared in good yields using Pd/Cu-catalysed Sonogashira cross-coupling reactions and/or lithium chemistry involving nucleophilic aromatic substitution. UV-Vis absorption and fluorescence spectra for 1a-d and 2 are reported. The X-ray crystal structures of 1b, 1c, 2, 3a and 3b show a variety of packing motifs, none of which involve arene-perfluoroarene stacking. The phase behaviour of 1a-1c has been studied by differential thermal analysis and transmitted polarised light microscopy. Compound 1b exhibits an ordered phase between 227.6 and 272.5 °C which is either hexatic B or crystal B. A 1:1 complex (4) between 1b and Zn(NO3)2 has been prepared; its crystal structure consists of zig-zag polymer chains held together by hydrogen bonds.
One-pot desilylation-Sonogashira coupling
Horstmann, Jan,Reger, Stefanie,Neumann, Beate,Stammler, Hans-Georg,Mitzel, Norbert W.
, p. 489 - 495 (2017/07/27)
Coupling of diethynyldiphenylsilane (1) with aryl halides under Sonogashira conditions affords the symmetrical diarylacetylenes bis(2-methylpyridin-5-yl)acetylene (2), bis(4-fluorophenyl)acetylene (3) and bis(4-trifluoromethylphenyl) acetylene (4) in 60% to 82% yield. In the case of 2, the by-product bis(2-methylpyridin-5-yl)butadiyne (2a) was isolated in 12% yield. The occurring desilylation reaction was investigated by treating bis(phenylethynyl)diphenylsilane (5) under the same conditions. The formation of 1-fluoro-4-(phenylethynyl)benzene (6), 1-trifluoromethyl- 4-(phenylethynyl)benzene (7) and (tetrafluoropyridin- 4-yl)ethynylbenzene (8) in 70 to 84% yield and the cleavage of hexaphenylcyclotrisiloxane were observed in all cases.
SNAr catalysis enhanced by an aromatic donor-acceptor interaction; Facile access to chlorinated polyfluoroarenes
Senaweera, Sameera,Weaver, Jimmie D.
, p. 7545 - 7548 (2017/07/12)
Selective catalytic SNAr reaction of polyfluoroaryl C-F bonds with chloride is shown. Stoichiometric TMSCl makes the reaction exergonic and allows catalysis, which involves ground state elevation of chloride, aromatic donor-acceptor interactions, and stabilization of the Meisenheimer complex. Traditional cross-coupling of the products is now possible and demonstrates the utility.
Preparation of p-substituted tetrafluoropyridyl derivatives via the tetrafluoropyridylcopper reagent
Van Nguyen, Ba,Burton, Donald J.
experimental part, p. 144 - 154 (2012/03/27)
A new and improved preparation of 4-iodo-2,3,5,6-tetrafluoropyridine from pentafluoropyridine is described. This iodopyridine is utilized for the in situ preparation of the 4-tetrafluoropyridylcopper reagent, 1, via two methods. The first method involves metathesis of the 4-tetrafluoropyridylcadmium reagent with Cu(I)Br at room temperature. The requisite cadmium reagent was readily prepared in situ via reaction between 4-iodotetrafluoropyridine with acid-washed cadmium powder in DMF at room temperature. The second method involves the in situ reaction of 4-tetrafluoropyridyltributyl-phosphonium tetrafluoroborate with Na2CO3 and Cu(I)Br in DMF at room temperature. 1 readily undergoes reaction with allylic halides, vinyl iodides, aryl halides, acid chlorides and acetylenic iodides at room temperature to stereospecifically afford the corresponding 4-tetrafluoropyridyl derivatives. An alternative route to the alkyne derivatives was developed via the Pd(0) catalyzed reaction of 4-iodotetrafluoropyridine with 1-alkynes.
REACTIONS OF PENTAFLUOROPYRIDINE WITH ORGANOSILICON COMPOUNDS IN THE PRESENCE OF FLUORIDE ION
Artamkina, G. A.,Kovalenko, S. V.,Beletskaya, I. P.,Reutov, O. A.
, p. 187 - 190 (2007/10/02)
The reaction of pentafluoropyridine with a series of organosilicon compounds RSiMe3 (I), where R = , EtCOCH2, PhCC, PhCH2, Ph*Cr(CO)3, in the presence of the F- ion was investigated.It was shown that the reaction of C5F5N with the f
