931-71-5Relevant articles and documents
Polysilane-Immobilized Rh-Pt Bimetallic Nanoparticles as Powerful Arene Hydrogenation Catalysts: Synthesis, Reactions under Batch and Flow Conditions and Reaction Mechanism
Miyamura, Hiroyuki,Suzuki, Aya,Yasukawa, Tomohiro,Kobayashi, Shu
supporting information, p. 11325 - 11334 (2018/09/06)
Hydrogenation of arenes is an important reaction not only for hydrogen storage and transport but also for the synthesis of functional molecules such as pharmaceuticals and biologically active compounds. Here, we describe the development of heterogeneous Rh-Pt bimetallic nanoparticle catalysts for the hydrogenation of arenes with inexpensive polysilane as support. The catalysts could be used in both batch and continuous-flow systems with high performance under mild conditions and showed wide substrate generality. In the continuous-flow system, the product could be obtained by simply passing the substrate and 1 atm H2 through a column packed with the catalyst. Remarkably, much higher catalytic performance was observed in the flow system than in the batch system, and extremely strong durability under continuous-flow conditions was demonstrated (>50 days continuous run; turnover number >3.4 × 105). Furthermore, details of the reaction mechanisms and the origin of different kinetics in batch and flow were studied, and the obtained knowledge was applied to develop completely selective arene hydrogenation of compounds containing two aromatic rings toward the synthesis of an active pharmaceutical ingredient.
Synthetic method for cis-1,4-cyclohexanediol
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Paragraph 0034-0035; 0039-0040, (2018/03/24)
The invention discloses a synthetic method for cis-1,4-cyclohexanediol, belonging to the field of organic chemical synthesis. According to the method, 4-(alkylacyloxy)cyclohexanone is used as a raw material and is only subjected to reduction and hydrolysis so as to conveniently synthesize cis-1,4-cyclohexanediol. The method can guarantee high selectivity of the reactions, and is high in the yieldof cis-1,4-cyclohexanediol and suitable for large-scale production.
Triphenylphosphine reduction of saturated endoperoxides
Erden, Ihsan,Gaertner, Christian,Saeed Azimi
supporting information; experimental part, p. 3986 - 3989 (2009/12/05)
(Figure Presented) Triphenylphosphine reduction of saturated endoperoxides derived from 6,6-dimethylfulvene and spiro[2.4]hepta-4,6-diene in the presence of nucleophiles results in the formation of products that mainly stem from deoxygenation followed by carbocation formation. Nucleophilic attack by solvent proceeds by an SN1 like mechanism; allyl shifts and cyclopropylcarbinyl-cyclobutyl rearrangements also occur. With the systems lacking carbocation-stabilizing groups, the deoxygenation step is preceded by attack of H2O at the phosphorus.
Raney ni-al alloy mediated hydrodehalogenation and aromatic ring hydrogenation of halogenated phenols in aqueous medium
Liu, Guo-Bin,Zhao, Hong-Yun,Zhang, Jie,Thiemannb, Thies
experimental part, p. 342 - 344 (2010/01/16)
Raney Ni-Al alloy in a dilute aqueous alkaline solution has been shown to be a very powerful reducing agent and is highly effective for the reductive dehalogenation of polyhalogenated phenols and aromatic ring hydrogenation of phenols to the corresponding cyclohexanols.
Pathways of liquid-phase oxidation of cyclohexanol
Puchkov,Buneeva,Perkel'
, p. 248 - 253 (2007/10/03)
The kinetics of product accumulation in uncatalyzed oxidation of cyclohexanol at 403 K was studied. Along with the compounds originating from oxidation of cyclohexanol at position 1 (cyclohexanone, hydrogen peroxide, 1-hydroxycyclohexyl hydroperoxide), products formed by oxidation of C-H bonds at positions 2-4 were detected: 2-, 3-, and 4-hydroxycyclohexyl hydroperoxides (cis and trans isomers), 1,2-, 1,3-, and 1,4-dihydroxycyclohexanes (cis and trans isomers), 2- and 4-hydroxycyclohexanones, and 2-cyclohexenone.
Acid-Catalyzed Hydrolysis of Bridged Bi- and Tricyclic Compounds. XXX. 7-Oxabicycloheptane: Kinetics and Mechanism
Lajunen, Martti,Uotila, Riikka
, p. 968 - 971 (2007/10/02)
7-Oxabicycloheptane (7-oxanorbornane) produces in concentrated (5.5 - 7.0 mol dm-3) aqueous perchloric acid mainly 3-cyclohexen-1-ol and a mixture (1:1) of cis- and trans-1,4-cyclohexanediols.The activation entropy, the solvent deuterium isotope effect and the slope parameter m(excit.) of the linear excess acidity plot as well as the products are in agreement with the A-1 hydrolysis mechanism.The data are compared with those recently measured for 7-oxa-5-oxo-2-bicycloheptene.
Molecular Recognition and Stereoselectivity: Geometrical Requirements for the Multiple Hydrogen-Bonding Interaction of Diols with a Multidentate Polyhydroxy Macrocycle
Kikuchi, Yasuaki,Kato, Yasushi,Tanaka, Yasutaka,Toi, Hiroo,Aoyama, Yasuhiro
, p. 1349 - 1354 (2007/10/02)
Resorcinol-dodecanal cyclotetramer 1 in CDCl3 forms hydrogen-bonded, 1/1 complexes with cyclohexanediols as well as with 2,4-pentane- and 2,5-hexanediol as their open-chain analogues and cyclohexanol and cis- and trans-4-tert-butylcyclohexanol.The affinities to 1 of cyclic diols (K=(1.1-10) * 102 M-1 at 25 deg C) are significantly larger than those of open-chain diols (36-43 M-1) and monools (8-11 M-1).Those of regio- and stereoisomers of cyclohexanediol depend on the configuration (axial-equatorial > diequatorial) and relative positions (1,4 >> 1,2 > 1,3) of the two OH groups involved and decrease in the order cis-1,4 (K=1.04 * 103) > cis-1,2 (2.64 * 102) > trans-1,3 (1.81 * 102) > trans-1,4 (1.29 * 102) > cis-1,3 (1.24 * 102) > trans-1,2 (1.06 * 102 M-1); the stereoselectivities are thus cis-1,4/trans-1,4 = 8.0, cis-1,2/trans-1,2 = 2.5, and trans-1,3/cis-1,3 = 1.5.The selectivities in the diol binding are discussed in terms of multiple hydrogen bonding of diol and 1.The relatively large binding constant (K) for cis-1,4-diol with one axial and one equatorial OH group is attributed to an effective and simultaneous two-point hydrogen bonding of the two OH groups with two adjacent binding sites of 1 as a multidentate host.
PALLADIUM(0) CATALYZED REACTIONS OF 1,4-EPIPEROXIDES
Suzuki, Masaaki,Oda, Yoshihisa,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 517 - 535 (2007/10/02)
The Pd(PPh3)4 catalyzed reaction of 2,3-saturated and 2,3-unsaturated 1,4-epiperoxides proceeds by courses markedly different from those of the previously reported transition metal catalyses.The Pd(0)-promoted reaction of 2,3-saturated epiperoxides gives the corresponding 4-hydroxy ketones and 1,4-diols as the major products.From 2,3-dedihydroepiperoxides are formed the corresponding 4-hydroxy enones, syn-1,2;3,4-diepoxides, and 1,4-diols.The results are interpreted in terms of competing Pd(0)/Pd(II) exchange mechanisms.Exposure of prostaglandin (PG) H2 methyl esterto Pd(PPh3)4 produces a mixture of methyl esters of PGD2, PGE2, PGF2α, and (5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoic acid.
Ruthenium(II)-Catalyzed Reactions of 1,4-Epiperoxides
Suzuki, Masaaki,Ohtake, Hiroaki,Kameya, Yoshimi,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 5292 - 5302 (2007/10/02)
The behavior of 1,4-epiperoxides in the presence of transition-metal complexes is highly dependent on the structures of the substrates and the nature of the metal catalysts.Reaction of saturated epiperoxides such as 1,3-epiperoxycyclopentane, 1,4-epiperoxycyclohexane, or dihydroascaridole catalyzed by RuCl2(PPh3)3 in dichloromethane gives a mixture of products arising from fragmentation, rearrangement, reduction, disproportionation, etc.Prostaglandin H2 methyl ester undergoes clean and stereospecific fragmentation to afford methyl(5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoate and malonaldehyde.Bicyclic 2,3-didehydro 1,4-epiperoxides give the syn-1,2:3,4-diepoxides by the same catalyst.The monocyclic analogues are transformed to a mixture of diepoxides and furan products.The stereochemical outcome of the epoxide formation reflects unique differences in the ground-state geometry of the starting epiperoxide substrates.FeCl2(PPh3)2 serves as a useful catalyst for the skeletal change of sterically hindered bicyclic 2,3-didehydro 1,4-epiperoxides to the syn-diepoxides.In addition, the Fe complex best effects the conversion of 1,4-unsubstituted 2,3-didehydro epiperoxides to furans.The Ru-catalyzed reactions are interpreted in terms of the intermediacy of inner-sphere radicals formed by atom transfer of the Ru(II) species to peroxy substrates, in contrast to the Fe-catalyzed reactions proceeding via free, outer-sphere radicals generated by an electron-transfer mechanism.
CoTPP-CATALYZED REACTION OF SATURATED BICYCLIC ENDOPEROXIDES
Balci, Metin,Akbulut, Nihat
, p. 1315 - 1322 (2007/10/02)
Saturated bicyclic endoperoxides were exposed to CoTPP (Cobalt-mesotetraphenylporphyrine) in chloroform, the peroxyde bond was cleaved and a mixture of products arising from fragmentation and reduction obtained.
