- Study of the catalytic activity of aluminum, zirconium and cerium pillared clays in the synthesis of 2,2-dimethyl-1,3-dioxolane
-
The purified Tunisian clay G and the commercialized American clay W were pillared with zirconium, aluminum and mixed pillars zirconium-aluminum, cerium-zirconium, cerium-aluminum, and cerium-zirconium-aluminum. These different clays were used in the synthesis of 2,2-dimethyl-1,3-dioxolane 3 by acetalyzation of acetone 2 with ethylene glycol 1 under autogenously pressure and without solvent. Results indicate that the yield of product 3 depends of the nature and the acidity of the clay used and the time of reaction.
- Mnasri, Saida,Besbes, Neji,Frini-Srasra, Najoua,Srasra, Ezzeddine
-
-
Read Online
- Bismuth carboxylates with brucite- and fluorite-related structures: Synthesis structure and properties
-
Three new compounds of bismuth, [C4N2H 10][Bi(C7H4NO4)(C7H 3NO4)]·H2O, I, [Bi(C5H 3N2O4) (C5H2N 2O4)], II, and [Bi(μ2-OH)(C 7H3NO4)], III, have been prepared by the reaction between bismuth nitrate and heterocyclic aromatic dicarboxylic acids, 2,6-pyridinedicarboxylic acid, 4,5-imidazoledicarboxylic acid, and 3,4-pyridinedicarboxylic acid, respectively, under hydrothermal conditions. The structures of all the compounds have linkages between Bi2O 2 and the corresponding dicarboxylate forming a simple molecular unit in I, a bilayer arrangement in II, and a three-dimensional extended structure in III. The topological arrangement of the nodal building units in the structures indicates that a brucite-related layer (II) and fluorite-related arrangement (III) can be realized in these structures. By utilizing the secondary interactions, one can correlate the structure of III to a Kagome-related one. The observation of such classical inorganic related structures in the bismuth carboxylates is noteworthy. Lewis acid catalytic studies on the formation of ketal suggest the possible participatory role of the lone pair of electrons. All the compounds are characterized employing elemental analysis, IR, UV-vis, and thermal studies.
- Sushrutha,Natarajan, Srinivasan
-
-
Read Online
- Low-Temperature Fluorination of Aerosol Suspensions of Hydrocarbons Utilizing Elemental Fluorine
-
This work describes a new concept in direct fluorination methodology and an apparatus designed to achieve conditions necessary for the rapid, continuous partial or complete fluorination of hydrocarbon molecules under controlled conditions of temperature and concentration.Results from the fluorination of neopentane are presented which indicate that although the degree of fluorination for a given set of conditions indicates a Gaussian distribution, investigation of specific isomers indicates significant deviations from statistical isomer distributions in fluorinated neopentanes.Photochemical assisted fluorinations of neopentane, 1,4-dioxane, cyclohexane, and 2,2-dimethyl-1,3-dioxolane are described which produce the perfluorinated analogues directly in good purity and in high yields.
- Adcock, James L.,Horita, Kiyoshi,Renk, Ehrengard B.
-
-
Read Online
- Synthesis of Asphaltene-Based Strongly Acidic Sulfonated Cation Exchangers and Determination of Their Catalytic Properties in the 2,2-Dimethyl-1,3-Dioxolane Synthesis Reaction
-
Abstract: Results of a study of the reaction products of asphaltene sulfonation with sulfuric acid in various temperature and time ranges have been described. The maximum sulfur content in sulfonated cation exchangers at an asphaltene sulfonation temperature of 100 and 120°С and a reaction time of 2 h has been determined. The maximum static exchange capacity of 4.3 meq/g has been found for the products of sulfonation with a sulfuric acid–oleum mixture. The asphaltene-based strongly acidic sulfocationite has been tested in the 2,2-dimethyl-1,3-dioxolane synthesis reaction.
- Borisov, D. N.,Foss, L. E.,Musin, L. I.,Musin, R. Z.,Nagornova, O. A.,Salikhov, R. Z.,Shabalin, K. V.,Yakubov, M. R.
-
-
Read Online
- H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
-
The dehydroxymethylation of primary alcohols is a promising strategy to transform biomass-derived oxygenates into hydrocarbon fuels. In this study, a novel, highly efficient, and reusable heterogeneous catalyst system was established for the H2-free dehydroxymethylation of primary alcohol using cerium oxide-supported palladium nanoparticles (Pd/CeO2). A wide range of aliphatic and aromatic alcohols including biomass-derived alcohols were converted into the corresponding one-carbon shorter hydrocarbons in high yields in the absence of any additives, accompanied by the production of H2 and CO. Pd/CeO2 was easily recovered from the reaction mixture and reused, retaining its high activity, thus, providing a simple and sustainable methodology to produce hydrocarbon fuels from biomass-derived oxygenates.
- Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
-
p. 1135 - 1139
(2020/12/29)
-
- Crystallinity after decarboxylation of a metal-carboxylate framework: indestructible porosity for catalysis
-
We report a curious case study of a Zr(iv)-carboxylate framework, which retains significant crystalline order after cascade thermocyclization of its linker components, and - more notably - after the crucial carboxylate links were severed by heat. Vigorous heat treatment (e.g., 450 °C and above) benzannulates the multiple alkyne groups on the linker to generate linked nanographene blocks and to afford real stability. The resultant Zr oxide/nanographene hybrid solid is stable in saturated NaOH and concentrated H3PO4, allowing a convenient anchoring of H3PO4into its porous matrix to enable size-selective heterogeneous acid catalysis. The Zr oxide components can also be removed by strong hydrofluoric acid to further enhance the surface area (up to 650 m2g?1), without collapsing the nanographene scaffold. The crystallinity order and the extensive thermal transformations were characterized by X-ray diffraction, scanning transmission electron microscopy (STEM), IR, solid state NMR and other instrumental methods.
- Cheng, Shengxian,Feng, Weijin,Gao, Wenpei,He, Jun,Hu, Jieying,Pan, Xiaoqing,Tieu, Peter,Xu, Zhengtao
-
p. 11902 - 11910
(2020/09/21)
-
- Solvent-free ketalization of polyols over germanosilicate zeolites: The role of the nature and strength of acid sites
-
Isomorphic substitution of silicon for germanium affords germanosilicate zeolites with weak acid centers capable of catalyzing key reactions such as Baeyer-Villiger oxidation of ketones and etherification of levulinic acid. Herein, we show for the first time that UTL (Si/Ge = 4.2) and IWW (Si/Ge = 7.2) germanosilicate zeolites are active and selective catalysts of polyol (e.g., ethylene glycol, glycerol and 1,4 butanediol) ketalization to dioxolanes. Large-pore IWW outperformed the extra-large-pore UTL zeolite in the ketalization of polyols, thus indicating diffusion limitations in bulky platelet-like UTL crystals. FTIR spectroscopy of adsorbed pyridine revealed the Lewis acidity of the UTL zeolite, whereas the more active IWW catalyst was characterized by water-induced Br?nsted acidity. Increasing the activation temperature (200-450 °C) reduced the concentration of Br?nsted acid centers in the IWW germanosilicate (i.e., 0.16; 0.07 and 0.05 mmol g-1 for Tact = 200, 300 and 450 °C, respectively) but increased the number of Lewis acid sites in both zeolites. Under optimized reaction conditions (e.g., acetone/glycerol = 25, Tact = 300 °C), almost total transformation of glycerol into solketal was achieved within 3 h of reaction time over the IWW zeolite at room temperature (>99% yield of the target product). The results from the present study clearly show that weak acid centers of germanosilicate zeolites can serve as active sites in ketalization reactions.
- Podolean, Iunia,Zhang, Jin,Shamzhy, Mariya,Parvulescu, Vasile I.,?ejka, Ji?í
-
p. 8254 - 8264
(2020/12/30)
-
- PROCESSES FOR FORMING GLYCOLS
-
This disclosure provides processes for forming glycols by upgrading hydrocarbons. In one embodiment, a process for forming a glycol includes introducing a first ether to a dihydrocarbyl peroxide to form a diether and a first alcohol. The process includes introducing the diether to water to form a glycol and a second alcohol. Processes of this disclosure may include one or more of: introducing a hydrocarbyl hydroperoxide to a third alcohol to form the dihydrocarbyl peroxide; oxidizing a first feed stream comprising a branched hydrocarbon to form the hydrocarbyl hydroperoxide and the first alcohol; and/or introducing the second alcohol to a catalyst to form a second ether.
- -
-
Paragraph 0095
(2020/05/28)
-
- Acid properties of organosiliceous hybrid materials based on pendant (fluoro)aryl-sulfonic groups through a spectroscopic study with probe molecules
-
Two different heterogeneous catalysts carrying aryl-sulfonic moieties, in which the aromatic ring was either fluorinated or not, were successfully synthesized. The multi-step synthetic approaches implemented involved the synthesis of the silyl-derivative, template-free one-pot co-condensation (at low temperature and neutral pH) and tethering reaction. A multi-technique approach was implemented to characterize the hybrid organic-inorganic catalysts involving TGA, N2 physisorption analysis, FTIR spectroscopy, and ss MAS NMR (1H, 13C, 29Si) spectroscopy. Specifically, the acidity of the organosiliceous hybrid materials was studied through the adsorption of probe molecules (i.e. CO at 77 K and NH3 and TMPO at room temperature) and a combination of FTIR and ss MAS NMR spectroscopy. The catalytic activity of the two hybrids was tested in the acetal formation reaction between benzaldehyde and ethylene glycol. Preliminary results indicated superior performances for the fluoro-aryl-sulfonic acid, compared to the non-fluorinated sample. The findings hereby reported open new avenues for the design of heterogeneous sulfonic acids with superior reactivity in acid-catalyzed reactions. Moreover, through the implementation of spectroscopic studies, using probe molecules, it was possible to investigate in detail the acidic properties of hybrid organosiliceous materials.
- Erigoni, Andrea,Paul, Geo,Meazza, Marta,Hernández-Soto, María Consuelo,Miletto, Ivana,Rios, Ramon,Segarra, Candela,Marchese, Leonardo,Raja, Robert,Rey, Fernando,Gianotti, Enrica,Díaz, Urbano
-
p. 6308 - 6317
(2019/11/20)
-
- Utilization of 1,3-Dioxolanes in the Synthesis of α-branched Alkyl and Aryl 9-[2-(Phosphonomethoxy)Ethyl]Purines and Study of the Influence of α-branched Substitution for Potential Biological Activity
-
Syntheses of α-branched alkyl and aryl substituted 9-[2-(phosphonomethoxy)ethyl]purines from substituted 1,3-dioxolanes have been developed. Key synthetic precursors, α-substituted dialkyl [(2-hydroxyethoxy)methyl]phosphonates were prepared via Lewis acid mediated cleavage of 1,3-dioxolanes followed by reaction with dialkyl or trialkyl phosphites. The best preparative yields were achieved under conditions utilizing tin tetrachloride as Lewis acid and triisopropyl phosphite. Attachment of purine bases to dialkyl [(2-hydroxyethoxy)methyl]phosphonates was performed by Mitsunobu reaction. Final α-branched 9-[2-(phosphonomethoxy)ethyl]purines were tested for antiviral, cytostatic and antiparasitic activity, the latter one determined as inhibitory activity towards Plasmodium falciparum enzyme hypoxanthine-guanine-xanthine phosphoribosyltransfesase. In most cases biological activity was only marginal.
- Pomeisl, Karel,Pohl, Radek,Snoeck, Robert,Andrei, Graciela,Kre?merová, Marcela
-
p. 119 - 156
(2019/01/04)
-
- Synthesis of dioxolanes and oxazolidines by silica gel catalysis
-
Abstract: Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, without solvent and under pressure, affords 1,3-dioxolanes. 2-Amino-2-methylpropanol also condensed with carbonyl compounds in the presence of silica gel or an acid-activated clay, without solvent and under pressure, produces oxazolidines. To explain these results, we propose that the glycol and the aminopropanol react with Br?nsted (H+) and Lewis acid sites (Si and Al) located on the surface of the catalysts, leading to the products via various ionic intermediates.
- Rohand, Taoufik,Savary, Jér?me,Markó, István E.
-
p. 1429 - 1436
(2018/06/25)
-
- First Example of a Nonanuclear Silver Sulfate Hybrid Cluster: Green Approach for Synthesis of Lewis Acid Catalyst
-
Finding a high nuclearity hybrid framework with novel structure and properties by an environmentally benign approach is a really challenging task. Herein, a green strategy for synthesis of a new inorganic-organic hybrid framework solid has been described. The framework contains silver sulfate clusters with nine different silver ions with shortest silver-silver connectivity. The present compound is the first example of nonanuclear silver sulfate hybrid framework with a new topology. The hybrid solid compound shows a highly active Lewis acidic nature for the various heterogeneous catalytic reactions such as cyanosilylation, ketalization, and esterification with quantitative transformation and recyclability.
- Paul, Avijit Kumar,Naveen, Kumari,Kumar, Nikhil,Kanagaraj, Rajendiran,Vidya,Rom, Tanmay
-
p. 6411 - 6416
(2018/11/21)
-
- First Example of a Nonanuclear Silver Sulfate Hybrid Cluster: Green Approach for Synthesis of Lewis Acid Catalyst
-
Finding a high nuclearity hybrid framework with novel structure and properties by an environmentally benign approach is a really challenging task. Herein, a green strategy for synthesis of a new inorganic-organic hybrid framework solid has been described. The framework contains silver sulfate clusters with nine different silver ions with shortest silver-silver connectivity. The present compound is the first example of nonanuclear silver sulfate hybrid framework with a new topology. The hybrid solid compound shows a highly active Lewis acidic nature for the various heterogeneous catalytic reactions such as cyanosilylation, ketalization, and esterification with quantitative transformation and recyclability.
- Paul, Avijit Kumar,Naveen, Kumari,Kumar, Nikhil,Kanagaraj, Rajendiran,Vidya,Rom, Tanmay
-
-
- Interpenetrated and Catenated Zinc Thiosulfates Frameworks with dia and qtz Nets: Synthesis, Structure, and Properties
-
Reactions between Zn(NO3)2·6H2O, Na2S2O3, 4,4′-bipyridine (bpy), 1,2-bis(4-pyridyl)ethene (bpe), 1,2-bis(4-pyridyl)ethane (bpa), and 1,3-bis(4-pyridyl)propane (bpp) under solvothermal conditions resulted in four new zinc thiosulfate hybrid compounds. Compound I has four-membered zinc thiosulfate rings connected by the ligand, 1,3-bis(4-pyridyl)propane (bpp) forming a two-dimensional structure. Compounds II-IV have one-dimensional zinc thiosulfate chains connected by the ligands, bpy (II), bpe (III), and bpa (IV) giving rise to three-dimensional structures. All the four-structures exhibit 3-fold interpenetration. Proton conductivity studies indicate reasonable proton mobility at 34 °C and at 98% relative humidity. The compounds also exhibit Lewis acid character and good photocatalytic activity for the decomposition of cationic dyes.
- Karthik, Rajendran,Natarajan, Srinivasan
-
p. 2239 - 2248
(2016/05/09)
-
- New approach to the synthesis of 1,3-dioxolanes
-
Application of ethanol to the synthesis of 1,3-dioxolanes by the condensation of carbonyl compounds with vicinal diols results in a high yield of the reaction product and considerably reduces the duration of the process. It is assumed that the effect of the ethanol is caused by the adduct formation with carbonyl compounds (hemiacetals) which behave as active intermediates of the condensation. A cyclic ketal of acetone with glycerol obtained with the help of ethanol was used as a basis component in the synthesis of a series of ketals substituting diol or carbonyl components by transketalyzation mechanism proceeding without water liberation.
- Vol'Eva,Belostotskaya,Malkova,Komissarova,Kurkovskaya,Usachev,Makarov
-
experimental part
p. 638 - 641
(2012/10/18)
-
- Indium triflate mediated tandem acetalisation-acetal exchange reactions under solvent-free conditions
-
Acyclic acetals and ketals undergo exchange reactions in the presence of catalytic quantities of indium(III) triflate and diols to generate the corresponding cyclic acetals and ketals in excellent yield. The protocol is rapid, employs mild conditions and can be adapted to employ solvent-free reaction conditions. We have further developed this methodology to encompass a tandem acetalisation-acetal exchange protocol which provides facile access to cyclic ketals from unreactive ketones also under very mild, solvent-free reaction conditions.
- Smith, Brendan M.,Graham, Andrew E.
-
experimental part
p. 6281 - 6283
(2011/12/14)
-
- PROCESS FOR THE PRODUCTION OF ETHYLENE GLYCOL
-
The present invention provides a process for the production of monoethylene glycol, said process comprising the steps of: (a) reacting ethylene oxide with a ketone in the presence of a solid acidic catalyst to form a ketal; and (b) hydrolysing the ketal with water to form monoethylene glycol, wherein the ketone contains in the range of from 4 to 20 carbon atoms.
- -
-
Page/Page column 10-12; 5/7; 7/7
(2011/02/24)
-
- Synthesis, characterization, and catalytic application of a cationic metal-organic framework: Ag2(4,4′-bipy)2(O 3SCH2CH2so3)
-
We report a silver-based cationic metal-organic framework with two mixed organic linkers directing the structure. The structure consists of ID Ag(4,4′-bipy) cationic chains arranged into closepacked layers. Weakly bound alkanedisulfonate anions charge-balance the layers, where only one oxygen of each sulfonate makes a long contact with the Ag. The unsaturated linear Ag centers likely allow the Lewis acidity displayed by the material for ketone protection as well as esterification. The material showed no reduction in yield after three catalytic runs with average 95% conversion yield for ketal formation and 57% for esterification without further water removal. In addition to hydrothermal conditions, the structure can be synthesized by reflux or room temperature, with almost identical catalytic ability. Other properties of this compound including chemical and thermal stability are also described.
- Fei, Honghan,Paw U, Latisha,Rogow, David L.,Bresler, Marc R.,Abdollahian, Yashar A.,Oliver, Scott R. J.
-
experimental part
p. 2027 - 2032
(2011/12/02)
-
- Hydrothermal synthesis of two cationic bismuthate clusters: An alkylenedisulfonate bridged hexamer, [Bi6O4(OH) 4(H2O)2][(CH2)2(SO 3)2]3 and a rare nonamer templated by triflate, [Bi9O8(OH)6][CF3SO 3]5
-
This paper reports the synthesis, characterization, and application of two cationic bismuthate clusters by anion templating. The compounds were synthesized under mild hydrothermal treatment and characterized by powder and single-crystal X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. The first material consists of a cationic hexanuclear bismuthate cluster octahedral in geometry and linked by 1,2-ethanedisulfonate molecules. This structure is thermally stable to about 235 °C. In the second compound, discrete cationic nonanuclear bismuthate clusters interact electrostatically with trifluoromethanesulfonate anions to pack into a nearly layered assembly. The material undergoes a transformation to Bi2O3 upon loss of the triflate groups at about 385 °C. Both materials demonstrate the use of sulfonate groups for the anion-directed assembly of these rare cationic inorganic structures. The application of the 3D octahedral bismuth cluster material toward acidic heterogeneous catalysis is also reported.
- Rogow, David L.,Fei, Honghan,Brennan, Daniel P.,Ikehata, Mariko,Zavalij, Peter Y.,Oliver, Allen G.,Oliver, Scott R. J.
-
experimental part
p. 5619 - 5624
(2010/08/05)
-
- Ruthenium-catalyzed carbonylation of allene: Direct synthesis of methacrylates and methacrylamides
-
Carbonylation reactions of allene in alcohols and amines in the presence of a ruthenium carbonyl catalyst under mild conditions gave methacrylates and methacrylamides, respectively, in good yields with an atom economy of 100%.
- Zhou, Da-Yang,Yoneda, Eiji,Onitsuka, Kiyotaka,Takahashi, Shigetoshi
-
p. 2868 - 2869
(2007/10/03)
-
- Acetalization and Transacetalization Reactions Catalyzed by Ruthenium, Rhodium, and Iridium Complexes with {2-{{Bis[3-(trifluoromethyl)phenyl]phosphino}methyl}-2-methylpropane-1,3-diyl}bis[bis[3-(trifluoromethyl)phenyl]phosphine] (MeC[CH2P(m-CF3C6H4)2]3)
-
The complexes [RhCl(3-n)(MeCN)n(CF3triphos)](CF3SO3)n (n = 1, 2; CF3triphos = MeC[CH2P(m-CF3C6H4)2]3) and [M(MeCN)3 (CF3triphos)](CF3SO3)n (M = Ru, n = 2; M = Ir, n = 3) are catalyst precursors for some typical acetalization and transacetalization reactions. The activity of these complexes is higher than those of the corresponding species containing the parent ligand MeC[CH2P(C6H5)2]3(Htriphos). Also the complexes [MCl3(tripod)] (tripod = Htriphos and CF3triphos) are active catalysts for the above reactions. The complex [RhCl2(MeCN)(CF3triphos)](CF3SO3) catalyzes the acetalization of benzophenone.
- Suelue, Mustafa,Venanzi, Luigi M.
-
p. 898 - 907
(2007/10/03)
-
- The continuous acid-catalyzed dehydration of alcohols in supercritical fluids: A new approach to the cleaner synthesis of acetals, ketals, and ethers with high selectivity
-
We report a new continuous method for forming ethers, acetals and ketals using solid acid catalysts, DELOXAN ASP or AMBERLYST 15, and supercritical fluid solvents. In the case of ether formation, we observe a high selectivity for linear alkyl ethers with little rearrangement to give branched ethers. Such rearrangement is common in conventional syntheses. Our approach is effective for a range of n-alcohols up to n-octanol and also for the secondary alcohol 2-propanol. In the reaction of phenol with an alkylating agent, the continuous reaction can be tuned to give preferential O- or C- alkylation with up to 49% O-alkylation with supercritical propene. We also investigate the synthesis of a range of cyclic ethers and show an improved method for the synthesis of THF from 1,4-butandiol under very mild conditions.
- Gray, William K.,Smail, Fiona R.,Hitzler, Martin G.,Ross, Stephen K.,Poliakoff, Martyn
-
p. 10711 - 10718
(2007/10/03)
-
- Ecofriendly fast batch synthesis of dioxolanes, dithiolanes, and oxathiolanes without solvent under microwave irradiation
-
2,2-Dimethoxypropane and 3,3-dimethoxypentane react with 1,2-ethanediol, thio, and oxathio analogues to give the corresponding protected carbonyls in high yield under mild solvent-free conditions. These environmentally benign conditions under microwave irradiation are applied to a large-scale synthesis.
- Perio, Bertrand,Dozias, Marie-Joelle,Hamelin, Jack
-
p. 428 - 430
(2013/09/08)
-
- PHOTOCHEMICAL CHLOROTRIFLUOROETHYLATION OF 1,2-, 1,3-, AND 1,4-DIOLS
-
The UV light-initiated reaction of chlorotrifluoroethylene with 1,2-ethanediol (I) proceeds only in the presence of acetone and affords 2-(2-chloro-1,1,2-trifluoroethyl)-2-methyl-1,3-dioxolane (VI).It has been proved that I is first photolyzed to acetaldehyde.Its acetalization in the reaction mixture gives 2-methyl-1,3-dioxolane (V) which then undergoes chlorotrifluoroethylation.The chlorotrifluoro derivative of 1,2-ethanediol XII was prepared by hydrolysis of 4-(2-chloro-1,1,2-trifluoroethyl)-2,2-dimethyl-1,3-dioxolane (XIII). 1,3-Propanediol (II) reacted to give 5-chloro-4,4,5-trifluoro-1,3-pentanediol (XVI).Analogous reaction of 1,4-butanediol (III) and 1,3-butanediol (IV) afforded, in addition to derivatives with chlorotrifluoroethyl group at the hydroxyl-bearing carbon atom (XVII from III, XIX and XX from IV), also the respective bis-chlorotrifluoroethyl derivatives XVIII and XXI as products arising by the 1,5- or 1,6-transfer in the radical intermediates.
- Dedek, Vaclav,Hemer, Ivan
-
p. 2743 - 2752
(2007/10/02)
-
- ASYMMETRIC SYNTHESIS USING ENANTIOMERICALLY PURE 2-(p-ANISYLSULFINYL)-2-CYCLOALKENONES
-
Conjugate additions of many organometallic reagents to 2-(p-anisylsulfinyl)-2-cycloalkenones, 2, proceed with much greater diastereoselectivity than additions to the corresponding 2-(p-tolylsulfinyl)-2-cycloalkenones, 7.Complexation of 2 with zinc dibromide followed by addition of various Grignard reagents lead, after reductive removal of the sulfoxide, to 3-substituted cycloalkanones of higher optical purity than those obtained from 7.Addition of methyltitanium triisopropoxide to 2-(p-anisylsulfinyl)-2-cyclohexenone, 2b, in the absence of zinc dibromide, proceeds with virtually complete asymmetric induction.
- Posner, Gary H.,Frye, Leah L.,Hulce, Martin
-
p. 1401 - 1408
(2007/10/02)
-