- Rapid and easy access to (E)-1,3-enynes, 1,3-diynes and allenes starting from propargylic acetals, exploiting the different reactivity of lithium and mixed lithium-potassium organometallic reagents
-
The treatment of propargylic acetals with various lithium and mixed lithium-potassium Schlosser reagents, has allowed a one-pot synthesis of (E)-1,3-enynes, 1,3-diynes and allenes, depending on the reaction conditions and the selected base. Various reacti
- Blangetti, Marco,Deagostino, Annamaria,Rosso, Helena,Prandi, Cristina,Zavattaro, Chiara,Venturello, Paolo
-
-
Read Online
- Photodimerization of anthracene derivatives in their neat solid state and in solid molecular compounds
-
The Cambridge Crystallographic Data Center provides valuable data for analysis and detection of compounds with potential to undergo photodimerization in the solid-state. Such analysis is presented for anthracene derivatives, and showed that there are many
- Zouev,Cao, Den-Ke,Sreevidya,Telzhensky,Botoshansky,Kaftory
-
-
Read Online
- Mechanosynthesis of Odd-Numbered Tetraaryl[n]cumulenes
-
A mechanochemical synthesis of one-dimensional carbon allotrope carbyne model compounds, namely tetraaryl[n]cumulenes (n=3, 5) was realized. Central for the mechanosynthesis of the cumulenic carbon nanostructures were the development of a mechanochemical Favorskii alkynylation-type reaction and the implementation of a solvent-free, acid-free reductive elimination with tin(II) chloride by ball milling.
- Ardila-Fierro, Karen J.,Bolm, Carsten,Hernández, José G.
-
p. 12945 - 12949
(2019/08/01)
-
- Phosphorus-Containing Bis-allenes: Synthesis and Heterocyclization Reactions Mediated by Iodine or Copper Dibromide
-
Bisphosphorylallenes were easily obtained in multigram scale from the Wittig-type rearrangement of bispropargyl alcohols. Unlike other conjugated bis-allenes, these reagents underwent a double cyclization mediated by iodine or copper dibromide leading to the formation of bis-1,2-oxaphospholenes.
- Essid,Laborde,Legros,Sevrain,Touil,Rolland,Ayad,Volle,Pirat,Virieux
-
supporting information
p. 1882 - 1885
(2017/04/11)
-
- A Mechanistic Study of Halogen Addition and Photoelimination from π-Conjugated Tellurophenes
-
The ability to drive reactivity using visible light is of importance for many disciplines of chemistry and has significant implications for sustainable chemistry. Identifying photochemically active compounds and understanding photochemical mechanisms is important for the development of useful materials for synthesis and catalysis. Here we report a series of photoactive diphenyltellurophene compounds bearing electron-withdrawing and electron-donating substituents synthesized by alkyne coupling/ring closing or palladium-catalyzed ipso-arylation chemistry. The redox chemistry of these compounds was studied with respect to oxidative addition and photoelimination of bromine, which is of importance for energy storage reactions involving X2. The oxidative addition reaction mechanism was studied using density functional theory, the results of which support a three-step mechanism involving the formation of an initial η1 association complex, a monobrominated intermediate, and finally the dibrominated product. All of the tellurophene derivatives undergo photoreduction using 430, 447, or 617 nm light depending on the absorption properties of the compound. Compounds bearing electron-withdrawing substituents have the highest photochemical quantum efficiencies in the presence of an alkene trap, with efficiencies of up to 42.4% for a pentafluorophenyl-functionalized tellurophene. The photoelimination reaction was studied in detail through bromine trapping experiments and laser flash photolysis, and a mechanism is proposed. The photoreaction, which occurs by release of bromine radicals, is competitive with intersystem crossing to the triplet state of the brominated species, as evidenced by the formation of singlet oxygen. These findings should be useful for the design of new photochemically active compounds supported by main-group elements.
- Carrera, Elisa I.,Lanterna, Anabel E.,Lough, Alan J.,Scaiano, Juan C.,Seferos, Dwight S.
-
supporting information
p. 2678 - 2689
(2016/03/12)
-
- Unexpected molecular flip in solid-state photodimerization
-
Three cocrystals of the light-stable compound 1,1,6,6-tetraphenyl-2,4- hexadiyne-1,6-diol (I) with light-sensitive molecules 1,2-dimethyl-2(1H)- pyridinone (a), 6-methyl-2(1H)-pyridinone (b) and 2-methyl-2(1H)-pyridinone (c) were exposed to UV light. It w
- Sreevidya, Thekku Veedu,Cao, Deng-Ke,Lavy, Tali,Botoshansky, Mark,Kaftory, Menahem
-
p. 936 - 941
(2013/08/24)
-
- A new tetraarylcyclopentadienone based low molecular weight gelator: Synthesis, self-assembly properties and anion recognition
-
A new class of tetraarylcyclopentadienones bearing 3-hydroxy-1-propynyl substituents has been synthesized. One of them, 3,4-bis (4-(3-hydroxy-3- methylbut-1-ynyl) phenyl)-2,5-diphenylcyclopenta-2,4-dienone, exhibits pronounced aggregation properties in various organic solvents responding to thermal and ultrasound stimuli and represents the first example of a tetraarylcyclopentadienone based low molecular weight organogelator. The hydroxydimethyl group on the ethynyl substituent proved to be essential to perform the gelation process. The 1H NMR analysis and FT-IR spectroscopy suggested that the intermolecular π-π and hydrogen bonding interactions of the gelator with the solvent are the main driving forces for the supramolecular assembly. The SEM images of xerogels show the characteristic gelation morphologies of 3D fibrous network structures. Fluorescence and UV/Vis absorption studies provided more information to define the molecular packing model in the gelation state. In addition the obtained gels show selective response to the fluoride anion. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.
- Boiani, Mattia,Baschieri, Andrea,Cesari, Cristiana,Mazzoni, Rita,Stagni, Stefano,Zacchini, Stefano,Sambri, Letizia
-
body text
p. 1469 - 1478
(2012/07/31)
-
- The rubrenic synthesis: The delicate equilibrium between tetracene and cyclobutene
-
Herein we describe the synthesis of new substituted tetraaryltetracenes, obtained by the dimerization of triarylchloroallenes, prepared from propargyl alcohols. The propargyl alcohols were prepared by two different synthetic strategies and then the alcohols were treated to obtain the corresponding acenes. In addition to the expected tetracene derivatives, we observed the formation of bis(alkylidene)cyclobutenes. When strong electron-donating substituents were present, the main product was the cyclobutene. We discuss a reaction mechanism that accounts for the formation of the cyclobutenes.
- Braga, Daniele,Jaafari, Abdelhafid,Miozzo, Luciano,Moret, Massimo,Rizzato, Silvia,Papagni, Antonio,Yassar, Abderrahim
-
scheme or table
p. 4160 - 4169
(2011/10/01)
-
- Kinetics of solid state photodimerization of 1,4-dimethyl-2-pyridinone in its molecular compound
-
The [4 + 4] photodimerization of 1,4-dimethyl-2-pyridinone (A) in its molecular compound with 1,1,6,6-tetraphenyl-2,4-hexadiyne-1,6-diol (I) was investigated by irradiation of a single crystal of the compound. The conversion to the product in a single-cry
- Cao, Deng-Ke,Sreevidya, Thekku Veedu,Botoshansky, Mark,Golden, Gilad,Brown Benedict, Jason,Kaftory, Menahem
-
experimental part
p. 7377 - 7381
(2011/01/06)
-
- Thermal cyclotrimerization of tetraphenyl[5]cumulene (tetraphenylhexapentaene) to a tricyclodecadiene derivative
-
Tetraphenyl[5]cumulene (tetraphenylhexapentaene) underwent cyclotrimerization in refluxing toluene for 10-15 min to give a tricyclodecadiene derivative in 68% yield. The Royal Society of Chemistry.
- Islam, Nazrul,Ooi, Takashi,Iwasawa, Tetsuo,Nishiuchi, Masaki,Kawamura, Yasuhiko
-
supporting information; experimental part
p. 574 - 576
(2009/06/17)
-
- Nickel-catalyzed dimerization of [5]cumulenes (Hexapentaenes)
-
Tetraaryl[5]cumulenes react with low-valent nickel complexes at the second double bond to produce novel [4]radialene derivatives that are head-to-head dimers of [5]cumulenes. The head-to-head dimers are also synthesized by a stepwise route. On the other hand, the nickel-catalyzed dimerization of [5]cumulenes with bulky substituents produces other types of extended [4]radialenes and [5]radialenones depending on the bulkiness of the terminal alkyl substituents. Thus, tetrakis-t-butyl[5]cumulene and 1,4-bis(2,2,6,6- tetramethylcyclohexylidene)[3]cumulene react at the central double bond to give the corresponding [4]radialene and [5]radialenone, whereas 1,4-bis(2,2,5,5- tetramethylcyclopentylidene)[3]cumulene and its benzo-annelated derivative react at the second double bond in a head-to-tail manner to afford the corresponding extended [4]radialenes. Tetrakis-t-butyl[5]radialenone was converted into [5]radialene by using a methylation-dehydration procedure. The extended [4]- and [5]radialenes and [5]radialenones have been fully characterized by spectroscopic analyses, X-ray crystallography, and/or independent chemical synthesis. The properties of these novel exocyclic π-electron systems have been investigated in detail. The aryl-substituted [4]radialenes exhibit facile bond rotation with low energy barriers. The [5]radialene and [5]radialenone form the corresponding cations easily by the addition of an acidic proton. The selectivity of the nickel-catalyzed dimerization of [5]cumulenes is discussed on the basis of theoretical calculations.
- Kuwatani, Yoshiyuki,Yamamoto, Gaku,Oda, Masaji,Iyoda, Masahiko
-
p. 2188 - 2208
(2007/10/03)
-
- SLIME REMOVER AND SLIME PREVENTING/REMOVING AGENT
-
A drainage slime remover capable of spreading a solution of a solid over slime generated wall surface portions, comprising a solid containing a microorganism growth retarding substance and a container which has a shape for permitting the installation thereof at the inlet or upper portion of a drain outlet and stores the solid characterized in that the container has drain flow-in holes having an opening capable of controlling a drain flow-in amount and provided in the upper surface or the upper side portion of the container and solution flow-out holes having an opening capable of controlling a flow-out amount of a solid solution and provided in the bottom or the lower side portion of the container or additionally in the side surface thereof, and a slime preventing/removing agent which can remove slime from portions such as kitchen sinks and bathroom drain outlets where slime is grown by metabolites such as miscellaneous germs and mildews and which can prevent the occurrence of slime safely and for an extended period of time.
- -
-
-
- Oxidative Coupling Reaction of Acetylene Compounds in the Solid State
-
Oxidative coupling of acetylene compound with cupric salt in the solid state was found to proceed efficiently and selectively.The coupling reaction of α,ω-diacetylenes in the solid state gave the linear oligomers in contrast with the formation of the cyclic products in the solution reaction.
- Toda, Fumio,Tokumaru, Yoshihisa
-
p. 987 - 990
(2007/10/02)
-
- Method of purifying a microbicide
-
A clathrate compound is produced if a powdery host compound which reacts with a microbicide to form the clathrate compound is added into an aqueous solution of the microbicide. If the microbicide is separated from the clathrate compound, a microbicide of high purity can be obtained.
- -
-
-
- New Hosts Bearing Two Triphenylcarbinol Groups and Crystal Structures of Their Acetone Inclusion Compounds
-
New hosts, m- and p-bis(diphenylhydroxymethyl)benzene and 2,2'-bis(diphenylhydroxymethyl)-1,1'-diphenyl, were found to exhibit high and selective inclusion tendencies toward a wide variety of guest compounds.Crystal structures of two representative acetone complexes were determined.
- Toda, Fumio,Kai, Akira,Toyotaka, Ritsuji,Yip, Wai-Hing,Mak, Thomas C. W.
-
p. 1921 - 1924
(2007/10/02)
-