10160-87-9Relevant academic research and scientific papers
A CONVENIENT ROUTE TO ALKYNES VIA PHASE TRANSFER CATALYSIS; ( APPLICATIONS OF PHASE TRANSFER CATALYSIS, PART 19 )
Dehmlow, Eckehard V.,Lissel, Manfred
, p. 1653 - 1658 (1981)
High yield, rapid formations of alkynes from vic-dibromides are possible using powered potassium hydroxide and catalytic amounts of lipophilic phase transfer catalysts.Reasons are given why molar amounts of expensive catalysts were necessary in earlier procedures.
Reactive carbon-chain molecules: Synthesis of 1-diazo-2,4-pentadiyne and spectroscopic characterization of triplet pentadiynylidene (H-C≡C-C- C≡C-H)
Bowling, Nathan P.,Halter, Robert J.,Hodges, Jonathan A.,Seburg, Randal A.,Thomas, Phillip S.,Simmons, Christopher S.,Stanton, John F.,McMahon, Robert J.
, p. 3291 - 3302 (2006)
1-Diazo-2,4-pentadiyne (6a), along with both monodeuterio isotopomers 6b and 6c, has been synthesized via a route that proceeds through diacetylene, 2,4-pentadiynal, and 2,4-pentadiynal tosylhydrazone. Photolysis of diazo compounds 6a-c (λ > 444 nm; Ar or N2, 10 K) generates triplet carbenes HC5H (1) and HC5D (1-d), which have been characterized by IR, EPR, and UV/vis spectroscopy. Although many resonance structures contribute to the resonance hybrid for this highly unsaturated carbon-chain molecule, experiment and theory reveal that the structure is best depicted in terms of the dominant resonance contributor of penta-1,4-diyn-3- ylidene (diethynylcarbene, H-C≡C-C-C≡C-H). Theory predicts an axially symmetric (D∞h) structure and a triplet electronic ground state for 1 (CCSD(T)/ANO). Experimental IR frequencies and isotope shifts are in good agreement with computed values. The triplet EPR spectrum of 1 (|D/hc| = 0.6157 cm-1, |E/hc| = 0.0006 cm-1) is consistent with an axially symmetric structure, and the Curie law behavior confirms that the triplet state is the ground state. The electronic absorption spectrum of 1 exhibits a weak transition near 400 nm with extensive vibronic coupling. Chemical trapping of triplet HC5H (1) in an O2-doped matrix affords the carbonyl oxide 16 derived exclusively from attack at the central carbon.
Quantitative production of butenes from biomass-derived γ-valerolactone catalysed by hetero-atomic MFI zeolite
Lin, Longfei,Sheveleva, Alena M.,da Silva, Ivan,Parlett, Christopher M. A.,Tang, Zhimou,Liu, Yueming,Fan, Mengtian,Han, Xue,Carter, Joseph H.,Tuna, Floriana,McInnes, Eric J. L.,Cheng, Yongqiang,Daemen, Luke L.,Rudi?, Svemir,Ramirez-Cuesta, Anibal J.,Tang, Chiu C.,Yang, Sihai
, p. 86 - 93 (2020)
The efficient production of light olefins from renewable biomass is a vital and challenging target to achieve future sustainable chemical processes. Here we report a hetero-atomic MFI-type zeolite (NbAlS-1), over which aqueous solutions of γ-valerolactone (GVL), obtained from biomass-derived carbohydrates, can be quantitatively converted into butenes with a yield of >99% at ambient pressure under continuous flow conditions. NbAlS-1 incorporates simultaneously niobium(v) and aluminium(iii) centres into the framework and thus has a desirable distribution of Lewis and Br?nsted acid sites with optimal strength. Synchrotron X-ray diffraction and absorption spectroscopy show that there is cooperativity between Nb(v) and the Br?nsted acid sites on the confined adsorption of GVL, whereas the catalytic mechanism for the conversion of the confined GVL into butenes is revealed by in situ inelastic neutron scattering, coupled with modelling. This study offers a prospect for the sustainable production of butene as a platform chemical for the manufacture of renewable materials.
Versatile methodology to synthesize oxygen-bridged nine- and ten-membered cycloalkanes by the hypoiodite reaction
Montana, Angel M.,Ponzano, Stefano,Kociok-Koehn, Gabriele,Font-Bardia, Merce,Solans, Xavier
, p. 4383 - 4401 (2007)
C-3 derivatives of 6-hydroxy-2,7-dimethyl-11-oxatricyclo[6.2.1.0 2,6]undecan-4-one reacted with lead tetraacetate (LTA) and iodine to afford, in good yield, 1,7-epoxycyclononanes, which are the result of a β-fragmentation of the C2-C6 bond adjacent to the tertiary hydroxy group on C-6. This β-fragmentation is followed by a ring contraction from a ten- to a nine-membered ring system, by a free-radical addition to the carbonyl group on C-4. The reaction of precursors (not functionalized on C-3) with LTA and iodine produced a β-fragmentation without any further structural rearrangement, affording 1,8-epoxycyclodecanes. The transformation of the carbonyl group on C-4 to acetate avoided radical additions and rearrangements affording, in high yield, the corresponding cyclodecanes. By this methodology, either 1,7-epoxycyclononane or 1,8-epoxycyclodecane could be synthesized, in good yield, by choosing the appropriate substitution pattern on C-3 in the substrate. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Sequential and tandem oxidation/acetalization procedures for the direct generation of acetals from alcohols
Smith, Brendan M.,Graham, Andrew E.
, p. 4891 - 4894 (2007)
Alcohols are transformed directly into either acyclic or cyclic acetals in both tandem and sequential oxidation/acetalization processes using manganese dioxide, trialkyl orthoformates and catalytic quantities of indium triflate.
Method for synthesizing bis(2-methyl-3-furyl) disulfide
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Paragraph 0057; 0061-0064; 0081; 0089-0094; 0115; 0119-0122, (2017/07/19)
The invention relates to a method for synthesizing bis(2-methyl-3-furyl) disulfide. The method comprises the following steps: (1) enabling acrolein to react with bromine to obtain a product 1; (2) adding the product 1 into an absolute ethyl alcohol solution of sodium hydroxide to prepare propiolaldehyde diethyl acetal; (3) enabling ethyl ether and bromoethane to react with chloroethane in presence of magnesium, then adding mixed liquid of the propiolaldehyde diethyl acetal and the ethyl ether and subsequently adding mixed liquid of acetaldehyde and ethyl ether for carrying out a reaction, and hydrolyzing to prepare 4-hydroxy-2-pentyne propanal diethyl acetal; (4) adding the 4-hydroxy-2-pentyne propanal diethyl acetal into a water solution containing sulfuric acid, pentane and potassium thiocyanate to prepare a product 4; (5) adding the product 4 into a sodium hydroxide water solution to prepare the bis(2-methyl-3-furyl) disulfide. Compared with the existing synthesis method, the method provided by the invention is easy in control of reaction conditions, fewer in side reactions, easy in control of intermediate products and higher in yield of a target product, thus having wide application prospect.
Propynal equivalents and diazopropyne: Synthesis of all mono-13C isotopomers
Seburg, Randal A.,Hodges, Jonathan A.,McMahon, Robert J.
experimental part, p. 1626 - 1643 (2009/10/17)
Mechanistic and spectroscopic investigations of reactive C 3H2 hydrocarbons necessitated the preparation of diazopropyne isotopomers bearing mono-13C substitution at each of the three unique positions. The diazo compounds and their tosylhydrazone precursors were prepared from the mono-13C isotopomers of propynal (in the form of either the aldehyde or the diethyl acetal). The introduction of 13C-labeling at either alkyne position in propynal utilized the Corey - Fuchs procedure for chain homologation.
Transition-metal-mediated synthesis of novel carbocyclic nucleoside analogues with antitumoral activity
Velcicky, Juraj,Lanver, Andreas,Lex, Johann,Prokop, Aram,Wieder, Thomas,Schmalz, Hans-Guenther
, p. 5087 - 5110 (2007/10/03)
A diversity-oriented, enantioselective synthesis of new (monoprotected) carbocyclic nucleoside analogues (CNAs) with the nucleobase attached to a 3-hydroxymethyl-4-trialkylsilyloxymethylcyclopent-2-en-l -yl scaffold was developed. As a key intermediate, racemic (5SR,8RS)-8-allyloxy-2-trimethylsilyl- 7-oxa-bicyclo[3.3.0]-oct-1-en-3-one was prepared from 1,1-diallyloxy-3- trimethylsilyl-2-propyne in a cobalt-mediated Pauson-Khand reaction. The enantiomerically pure material was obtained through efficient kinetic resolution (selectivity factor s ≥ 40 at -78°C) by means of an oxazaborolidine- catalyzed borane reduction (CBS reduction) with catecholborane. The absolute configuration of the resolved products was determined by CD spectroscopy, Mosher ester analysis, and chemical correlation. Subsequent steps involve diastereoselective ketone reduction and fully regio- and diastereoselective introduction of the nucleobase through Pd°-catalyzed allylic substitution. The generality of the method was demonstrated by preparation of CNAs in both enantiomeric series with all five natural nucleobases, as well as 5-bromouracil, 5-fluorouracil, and 6-chloropurine. Screening of the various compounds in a cytotoxicity assay with BJAB and ALL tumor cell lines revealed that some of the compounds possess pronounced antitumoral properties (LD50 values down to 9 μM, as determined by lactate dehydrogenase release after 48 h). By measuring DNA fragmentation, it could be shown that the activity results from induction of apoptosis.
Formation of acetylenic acetals by ring opening of 1,1,2-trihalocyclopropanes under phase-transfer conditions
Sydnes, Leiv K.,Bakstad, Einar
, p. 446 - 453 (2007/10/03)
A number of substituted 1,1-dibromo- and 1,1-dichlorocyclopropanes with an additional chlorine or bromine atom attached to C-2 were synthesized in reasonabk to good yields by dihalocarbene addition to the corresponding alkenes under phase-transfer conditions. When the trihalides were treated with 50% aqueous sodium hydroxide in the presence of ethanol. triethylbenzylammonium chloride and dichloromethane. most of the compounds underwent ring opening and afforded mixtures of acetylenic acetals, usually in good yields. The reaction most likely involves cyclopropene intermediates, which in some cases also rearrange to a minor extent to the corresponding vinylcarbenes and afford α,β-unsaturated aldehydes. Acta Chemica Scandinavica 1996.
Action d'organometalliques sur les dialkylphenylorthoformiates. Preparation facile d'acetals
Barbot, Francis,Poncini, Laurence,Randrianoelina, Benjamin,Miginiac, Philippe
, p. 4016 - 4035 (2007/10/02)
The reaction of dialkylphenylorthoformiates with organometallic compounds proceeds with a good yield, at room temperature, giving the corresponding dialkylacetals ; it allows an easy preparation of acetals which are otherwise difficult to prepare.
