18787-63-8Relevant academic research and scientific papers
Chlorinated Acetylenes from the Nudibranch Diaulula sandiegensis
Walker, Roger P.,Faulkner, John D.
, p. 1475 - 1478 (1981)
The nudibranch mollusc Diaulula sandiegensis contained nine chlorinated acetylenes, 1-9, all of which were relatively unstable when purified.The nine metabolites were identified as (1Z,3E,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-15-one (1), (1Z,3Z,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-15-one (2), (1Z,3E,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-15-ol (3), (1Z,3Z,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-15-ol (4), (1E,3E,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-15-ol (5), (1Z,3E,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-14-ol (6), (1Z,3Z,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-14-ol (7), (1E,3E,9Z)-1-chlorohexadeca-5,7-diyne-1,3,9-trien-14-ol (8), and (1Z,3E)-1-chlorohexadeca-1,3-diene-5,7-diyn-14-ol (9) by analysis of spectral data.The chlorinated acetylenes 1-9 are believed to be involved in the chemical defense mechanism of the nudibranch.
Oxidation of heavy 1-olefins (C12= s(-) C20=) with TBHP using a modified Wacker system
Escola,Botas,Vargas,Bravo
, p. 34 - 39 (2010)
The oxidation of heavy olefins (C12-C20) was carried out using a modified Wacker system with TBHP as oxidant and acetonitrile as solvent at 80 °C. This system allowed the oxidation of 1-octadecene giving rise to 90% conversion with 60% selectivity towards 2-octadecanone after 2 h while the addition of β-cyclodextrins did not increase the production of 2-octadecanone. The oxidation of a equimolar mixture of n-dodecane + 1-dodecene enhanced markedly the selectivity towards 2-dodecanone yielding 63% instead of 34% in the absence of n-paraffin after 2 h, likely due to a dilution effect of the n-dodecane which reduces the extent of the isomerization reactions. The oxidation of a equimolar mixture C12= + C16= + C20= in the presence of equimolar amounts of their corresponding n-paraffins gave rise to practically complete conversion and selectivities toward 2-methylketones within 70-90% enhancing with decreasing chain length due to their higher solubility in the biphasic system. The activity of the catalyst dropped after two reaction cycles indicating its deactivation by the formation of palladium clusters. However, it was possible to obtain similar results in terms of activity and selectivity by increasing the (1-dodecene)/(PdCl2) ratio to 100, which is expected to increase the catalyst lifetime by decreasing the extent of palladium aggregation. In this regard, the reported system is rather promising for the oxidation of heavy 1-olefins towards methyl ketones.
A new vanadium(IV)-bridged polyoxotungstate containing mixed valence-antimony(III,V)
Wang, Bin,Xu, Ling-Xiao,Meng, Rui-Qi,Suo, Lin,Li, Bao,Wu, Li-Xin,Bi, Li-Hua
, p. 274 - 278 (2013)
A new mixed-valence SbV/III containing vanadium-substituted polyoxotungstate Na10[{SbV(OH)3} 2{VIV-O(H2O)}2{Sb IIIW9O33}2]·32H2O (1-Na) has been synthesized by routine synthetic reaction and characterized by IR, XPS, elemental analysis. The polyoxoanion [{SbV(OH)3}2{V IVO(H2O)}2{SbIIIW9O33}2]10 (1) consists of two trilacunary species β-B-SbIIIW9O 33 connected by two VIVO(H2O) groups and two SbV(OH)3 units. The cyclic voltammetry and catalytic activity of 1-Na for the oxidation of n-hexadecane under green condition have been measured.
Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
supporting information, p. 10164 - 10167 (2018/09/13)
Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
Organoruthenium-supported polyoxotungstate - Synthesis, structure and oxidation of n-hexadecane with air
Meng, Rui-Qi,Wang, Bin,Sui, Hui-Min,Li, Bao,Song, Wei,Wu, Li-Xin,Zhao, Bing,Bi, Li-Hua
, p. 1935 - 1942 (2013/05/23)
A ruthenium complex, KNa[Ru2(C6H6) 2(CH3COO)6] (Ru-KNa), and its polyoxotungstate derivative, Na6[{Ru(C6H6)}2W 8O28(OH)2]·16H2O (Ru-Na), have been successfully isolated from routine synthetic reactions and characterized by X-ray single-crystal structure analysis, IR spectroscopy and elemental analysis. A remarkable aspect of Ru-KNa is that it has two ligand types, benzene and acetate, and the acetate ligands are connected exclusively by a central Na cation to form a dimeric sandwich-type structure, which is further connected by K cations to construct the 3D structures. Based on complex Ru-KNa, the compound Ru-Na was synthesized, and it consists of two {Ru(C 6H6)} units linked to a [W8O 28(OH)2]10- fragment by three Ru-O(W) bonds to result in an assembly with idealized C2 symmetry in which the polyanions form 3D structures by the connection of Na chains. Subsequently, the compound Ru-Na was anchored on (3-aminopropyl)triethoxysilane (apts) modified SBA-15 to prepare the solid catalysts, which were characterized by powder XRD, N2 adsorption measurements and FTIR spectroscopy. Finally, the catalytic efficiency of Ru-Na was assessed in the oxidation of n-hexadecane with air without any additives and solvents. The results indicated that Ru-Na is a heterogeneous catalyst and exhibits higher catalytic activity than previously reported Ru-containing polyoxotungstates. Copyright
Polydentate pyridyl ligands and the catalytic activity of their iron(II) complexes in oxidation reactions utilizing peroxides as the oxidants
Lenze, Matthew,Sedinkin, Sergey L.,Bauer, Eike B.
, p. 161 - 171 (2013/06/27)
The paper describes the synthesis of iron(II) complexes bearing new polydentate N,O-coordinating pyridyl ligands and their catalytic application in oxidation reactions employing peroxides as the oxidants. The tridentate N,O,N (10) and N,N,O (11) ligands, the tetradentate N,N,O,N ligand 12 and the pentadentate N,N,N,O,N-coordinating ligand 16 were synthesized, and obtained as oils or solids in 74-93% isolated yields. The ligands were subsequently converted to the iron complexes [Fe(10)2](OTf)2, [Fe(11)2](OTf)2, [Fe(12)(OTf)2] and [Fe(16)(OTf)](OTf), which were obtained as tan powders in 90-94% yield and characterized by various instrumental techniques. Preliminary screening experiments revealed that all complexes are catalytically active in the oxidation of secondary alcohols and benzylic methylene groups to the corresponding ketones. Optimization experiments with the complex [Fe(12)(OTf)2] yielded a system that provided under mild condition ketones from benzylic methylene groups and secondary alcohols in 63-90% isolated yields (3 mol% catalyst loading, 3 equiv. H2O2 in CH 3CN for 2 h at room temperature). Similar conditions utilizing environmentally friendly acetone as the solvent and 4 equiv. tBuOOH resulted in 36-65% isolated yields for some of the substrates, indicating a somewhat lower catalytic activity in that solvent. For the complexes [Fe(10)2](OTf)2 (two tridentate ligands), [Fe(12)(OTf)2] (one tetradentate ligand) and [Fe(16)(OTf)](OTf) (one pentadentate ligand), the product formation for a test reaction was followed over time at significantly reduced catalyst loading to determine activities. Under these conditions, the complex [Fe(10)2](OTf)2 exhibited a somewhat lower catalytic activity compared to the other two complexes. Thus, the denticity seems to have an impact on catalytic activity although it is not dramatic, and a higher denticity appears to be beneficial for catalysis.
Nanosized gold-catalyzed selective oxidation of alkyl-substituted benzenes and n-alkanes
Biradar, Ankush V.,Asefa, Tewodros
scheme or table, p. 19 - 26 (2012/10/08)
We report the synthesis of nanoporous silica-supported gold nanoparticle catalysts and their selective and efficient catalytic properties toward oxidation reactions of various substituted alkylbenzenes and linear alkanes. The Au nanoparticles were synthesized by reducing Au(III) ions in situ within the nanopores of hemiaminal-functionalized mesoporous silica by using the supported hemiaminal groups as reducing agents. The resulting mesoporous silica-supported gold nanoparticles efficiently catalyzed the oxidation reactions of different alkyl-substituted benzenes and linear alkanes with t-butyl hydroperoxide (TBHP) as an oxidant. The catalytic reactions gave up to ～99% reactant conversion and up to ～100% selectivity toward ketone products in some cases. This high selectivity toward ketone products by the catalysts was unprecedented, especially considering the fact that only mild reaction conditions and no additives were employed during the reactions.
Ethylene carbonate as a unique solvent for palladium-catalyzed Wacker oxidation using oxygen as the sole oxidant
Wang, Jing-Lun,He, Liang-Nian,Miao, Cheng-Xia,Li, Yu-Nong
experimental part, p. 1317 - 1320 (2010/06/16)
Ethylene carbonate (EC) as a unique solvent for the Wacker oxidation of higher alkenes and aryl alkenes has been successfully developed using molecular oxygen as the sole oxidant, in which colloidal Pd nanoparticles stabilized in EC are considered to facilitate its reoxidation under cocatalyst-free conditions. The Royal Society of Chemistry 2009.
Novel synthesis of methyl ketones based on the blaise reaction
Rao, H. Surya Prakash,Padmavathy,Vasantham,Rafi, Shaik
experimental part, p. 1825 - 1834 (2009/10/02)
A facile two-step synthesis of methyl ketones from alkyl nitriles via the Blaise conversion of nitriles into -keto esters and acid-mediated hydrolysis followed by decarboxylation of the resulting -keto esters is described. Copyright Taylor & Francis Group, LLC.
Convenient and efficient Pd-catalyzed regioselective oxyfunctionalization of terminal olefins by using molecular oxygen as sole reoxidant
Mitsudome, Takato,Umetani, Takuya,Nosaka, Naoya,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 481 - 485 (2007/10/03)
(Chemical Equation Presented) Just the one: The combination of palladium dichloride and N,N-dimethylacetamide (DMA) constitutes a highly efficient and reusable catalytic system, which uses molecular oxygen as the sole reoxidant for liquid-phase Wacker oxidation and acetoxylation of terminal olefins to the corresponding methyl ketones and linear allylic acetates, respectively (see scheme). 2006 Wiley-VCH Verlag GmbH Co. KGaA.
