cas 2979-19-3, 3,3-Dimethylcyclohexanone | Articles data

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Efficient syntheses of insect sex pheromones emitted by the boll weevil and the red bollworm moth
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Wollenberg,Peries
p. 297 - 300
(1979)
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House,H.O.,Wilkins,J.M.
p. 4031 - 4033
(1976)
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Fragmentation-cyclization reactions by photoinduced electron transfer
Irradiation of unsaturated bicyclo[4.1.0]heptanones and bicyclo[3.1.0]hexanones under reductive PET conditions leads to a regioselective cleavage of the cyclopropane moiety followed by cyclization. By this method various types of ring anellated and spirocyclic compounds are accessible.
Kirschberg, Thorsten
p. 7217 - 7220
(1994)
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Gates,Shepard
p. 4125,4128
(1962)
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Posner,G.H.,Brunelle,D.J.
p. 907 - 908
(1973)
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A gatekeeper residue for inhibitor sensitization of protein tyrosine phosphatases
Allele-specific enzyme inhibitors are powerful tools in chemical biology. However, few general approaches for the discovery of such inhibitors have been described. Herein is reported a method for the sensitization of protein tyrosine phosphatases (PTPs) to small-molecule inhibition. It is shown that mutation of an active-site isoleucine to alanine (I219A) sensitizes PTP1B to inhibition by a class of thiophene-based inhibitors. This sensitization strategy succeeds for both 'orthogonal' inhibitors, designed to be incompatible with wild-type PTP active sites, and previously optimized wild-type PTP inhibitors. The finding that the I219A mutation sensitizes phosphatase domains to a variety of compounds suggests that isoleucine 219 may act as a 'gatekeeper' residue that can be widely exploited for the chemical-genetic analysis of PTP function.
Bishop, Anthony C.,Blair, Elizabeth R.
p. 4002 - 4006
(2006)
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Buechi,Jeger,Ruzicka
p. 241,245
(1948)
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Potential inhibitors of collagen biosynthesis. 5,5-Difluoro-DL-lysine and 5,5-dimethyl-DL-lysine and their activation by lysyl-tRNA ligase
The synthesis of lysine analogues wherein blocking groups are substituted at position 5, the site of hydroxylation by peptidyl lysine hydroxylase, is described. Thus, 5,5-diflurolysine (1) and 5,5-dimethyllysine (2) were synthesized via a four- and six-step sequence, respectively, starting from ketone precursors. The propensity for these lysine analogues to be incorporated into procollagen protein in vivo was assessed by their ability to stimulate the lysine-dependent ATP-PP(i) exchange reaction in the presence of lysyl-tRNA ligase in vitro. The difluoro analogue 1 stimulated exchange, but at a K(m) (1.3 x 10-3 M) 1000 times greater than that for lysine itself. The dimethyl analogue 2 did not stimulate exchange, but at high concentrations was a competitive inhibitor of lysine, with an apparent K(i) of 1.6 x 10-2 M. Thus, electronegative and/or bulky substituents at the 5 position of lysine cannot be tolerated by lysyl-tRNA ligase, and this position must be kept free in lysine analogues specifically designed to block collagen biosynthesis.
Shirota,Nagasawa,Elberling
p. 1623 - 1627
(1977)
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Reduction of α,β-unsaturated carbonyl compounds and 1,3-diketones in aqueous media, using a raney ni-al alloy
The treatment of α,β-unsaturated carbonyl compounds and 1,3-diketones with Raney Ni-Al alloy in aqueous media yielded as major reaction products the corresponding saturated alcohols and/or the corresponding hydrocarbons, in a complete transformation of the starting material.
Simion, Cristian,Mitoma, Yoshiharu,Katayama, Yumi,Simion, Alina Marieta
p. 51 - 55
(2021/02/03)

Reduction of α,β-Unsaturated carbonyl compounds and 1,3-Diketones in aqueous media, using a raney ni-al alloy
The treatment of α,β-unsaturated carbonyl compounds and 1,3-diketones with Raney Ni-Al alloy in aqueous media yielded as major reaction products the corresponding saturated alcohols and/or the corresponding hydrocarbons, in a complete transformation of the starting material.
Katayama, Yumi,Mitoma, Yoshiharu,Simion, Alina Marieta,Simion, Cristian
p. 51 - 55
(2020/07/23)

A method for synthesis of 3, 3 - dimethyl cyclohexanone (by machine translation)
The present application relates to the field of drug synthesis, in particular, relates to 3, 3 - dimethyl cyclohexanone a synthesizing method of. The invention synthetic method mild reaction conditions, easy to enlarge production; the various reagent are on the market are easy, and the cost is low; effectively through the intermediate step of the oxidation reaction of the by-product 3, 3 - dimethyl cyclohexanol turns into the product 3, 3 - dimethyl cyclohexanone. Improves the yield, and reduces the difficulty of the purification. (by machine translation)
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Paragraph 0012; 0013

(2019/07/01)

Iron-catalyzed oxidative functionalization of C(sp3)-H bonds under bromide-synergized mild conditions
An efficient oxidation and functionalization of C-H bonds with an inorganic-ligand supported iron catalyst and hydrogen peroxide to prepare the corresponding ketones was achieved using the bromide ion as a promoter. Preliminary mechanistic investigations indicated that the bromide ion can bind to FeMo6 to form a supramolecular species (FeMo6·2Br), which can effectively catalyze the reaction.
Yu, Han,Zhao, Qixin,Wei, Zheyu,Wu, Zhikang,Li, Qi,Han, Sheng,Wei, Yongge
supporting information
p. 7840 - 7843
(2019/07/12)

Catalyst-controlled aliphatic C—H oxidations
The invention provides simple small molecule, non-heme iron catalyst systems with broad substrate scope that can predictably enhance or overturn a substrate's inherent reactivity preference for sp3-hybridized C—H bond oxidation. The invention also provides methods for selective aliphatic C—H bond oxidation. Furthermore, a structure-based catalyst reactivity model is disclosed that quantitatively correlates the innate physical properties of the substrate to the site-selectivities observed as a function of the catalyst. The catalyst systems can be used in combination with oxidants such as hydrogen peroxide to effect highly selective oxidations of unactivated sp3 C—H bonds over a broad range of substrates.
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(2018/04/20)

Aerobic oxidation of secondary alcohols in water with ABNO/tert-butyl nitrite/KPF6catalytic system
A green and efficient transition-metal free ABNO/tert-butyl nitrite/KPF6-catalyzed aerobic oxidation of secondary alcohols in water has been achieved. Under the optimal reaction conditions, a number of secondary aliphatic alcohols and secondary benzylic alcohols can be converted to their corresponding ketones in excellent yields (up to 99%).
Ma, Jiaqi,Hong, Chao,Wan, Yan,Li, Meichao,Hu, Xinquan,Mo, Weimin,Hu, Baoxiang,Sun, Nan,Jin, Liqun,Shen, Zhenlu
p. 652 - 657
(2017/01/25)

An unexpected transmetalation intermediate: Isolation and structural characterization of a solely CH3 bridged di-copper(i) complex
Structural characterization of unsupported, two metal centres bridging methyl groups is rare. They have been proposed as transmetalation intermediates in cuprate chemistry, but as yet no structural evidence has been presented. We have isolated a di-copper(i) complex with solely a methyl ligand bridging two Cu(i) atoms, representing a new bonding mode of CH3.
Molteni, Roberto,Bertermann, Rüdiger,Edkins, Katharina,Steffen, Andreas
supporting information
p. 5019 - 5022
(2016/04/19)

From DNA to catalysis: A thymine-acetate ligated non-heme iron(III) catalyst for oxidative activation of aliphatic C-H bonds
A non-heme, iron(iii)/THA(thymine-1-acetate) catalyst together with H2O2 as an oxidant is efficient in oxidative C-H activation of alkanes. Although having a higher preference for tertiary C-H bonds, the catalyst also oxidizes aliphatic secondary C-H bonds into carbonyl compounds with good to excellent conversions. Based on the site selectivity of the catalyst and our mechanistic studies the reaction proceeds via an Fe-oxo species without long lived carbon centered radicals.
Al-Hunaiti, Afnan,R?is?nen, Minn?,Repo, Timo
supporting information
p. 2043 - 2046
(2016/02/05)

Readily Accessible Bulky Iron Catalysts exhibiting Site Selectivity in the Oxidation of Steroidal Substrates
Bulky iron complexes are described that catalyze the site-selective oxidation of alkyl C-H bonds with hydrogen peroxide under mild conditions. Steric bulk at the iron center is introduced by appending trialkylsilyl groups at the meta-position of the pyridines in tetradentate aminopyridine ligands, and this effect translates into high product yields, an enhanced preferential oxidation of secondary over tertiary C-H bonds, and the ability to perform site-selective oxidation of methylenic sites in terpenoid and steroidal substrates. Unprecedented site selective oxidation at C6 and C12 methylenic sites in steroidal substrates is shown to be governed by the chirality of the catalysts.
Font, David,Canta, Mercè,Milan, Michela,Cussó, Olaf,Ribas, Xavi,Klein Gebbink, Robertus J. M.,Costas, Miquel
supporting information
p. 5776 - 5779
(2016/05/09)

Platinum Nanoparticles Stabilized by Glycerodendrimers: Synthesis and Application to the Hydrogenation of α,β-Unsaturated Ketones under Mild Conditions
Air-stable platinum nanoparticles stabilized by glycerodendrimers were prepared in water and analyzed by TEM. These platinum nanoparticles showed good catalytic activity for the reduction of α,β-unsaturated ketones to saturated ketones at room temperature in water or in water/THF (1:1) under H2 (101.3 kPa). The catalytic species was recovered and recycled several times.
Menot, Bérengère,Salmon, Lionel,Bouquillon, Sandrine
p. 4518 - 4523
(2015/10/06)

Trapping a Highly Reactive Nonheme Iron Intermediate That Oxygenates Strong C-H Bonds with Stereoretention
An unprecedentedly reactive iron species (2) has been generated by reaction of excess peracetic acid with a mononuclear iron complex [FeII(CF3SO3)2(PyNMe3)] (1) at cryogenic temperatures, and characterized spectroscopically. Compound 2 is kinetically competent for breaking strong C-H bonds of alkanes (BDE ≈ 100 kcal·mol-1) through a hydrogen-atom transfer mechanism, and the transformations proceed with stereoretention and regioselectively, responding to bond strength, as well as to steric and polar effects. Bimolecular reaction rates are at least an order of magnitude faster than those of the most reactive synthetic high-valent nonheme oxoiron species described to date. EPR studies in tandem with kinetic analysis show that the 490 nm chromophore of 2 is associated with two S = 1/2 species in rapid equilibrium. The minor component 2a (～5% iron) has g-values at 2.20, 2.19, and 1.99 characteristic of a low-spin iron(III) center, and it is assigned as [FeIII(OOAc)(PyNMe3)]2+, also by comparison with the EPR parameters of the structurally characterized hydroxamate analogue [FeIII(tBuCON(H)O)(PyNMe3)]2+ (4). The major component 2b (～40% iron, g-values = 2.07, 2.01, 1.95) has unusual EPR parameters, and it is proposed to be [FeV(O)(OAc)(PyNMe3)]2+, where the O-O bond in 2a has been broken. Consistent with this assignment, 2b undergoes exchange of its acetate ligand with CD3CO2D and very rapidly reacts with olefins to produce the corresponding cis-1,2-hydroxoacetate product. Therefore, this work constitutes the first example where a synthetic nonheme iron species responsible for stereospecific and site selective C-H hydroxylation is spectroscopically trapped, and its catalytic reactivity against C-H bonds can be directly interrogated by kinetic methods. The accumulated evidence indicates that 2 consists mainly of an extraordinarily reactive [FeV(O)(OAc)(PyNMe3)]2+ (2b) species capable of hydroxylating unactivated alkyl C-H bonds with stereoretention in a rapid and site-selective manner, and that exists in fast equilibrium with its [FeIII(OOAc)(PyNMe3)]2+ precursor.
Serrano-Plana, Joan,Oloo, Williamson N.,Acosta-Rueda, Laura,Meier, Katlyn K.,Verdejo, Bego?a,García-Espa?a, Enrique,Basallote, Manuel G.,Münck, Eckard,Que, Lawrence,Company, Anna,Costas, Miquel
supporting information
p. 15833 - 15842
(2016/01/09)

The iron(II) complex [Fe(CF3SO3)2(mcp)] as a convenient, readily available catalyst for the selective oxidation of methylenic sites in alkanes
The efficient and selective oxidation of secondary C-H sites of alkanes is achieved by using low catalyst loadings of a non-expensive, readily available iron catalyst [Fe(II)(CF3SO3)2(mcp)], {Fe-mcp, [mcp=N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)cyclohexane-trans-1,2-diamine]}, and hydrogen peroxide (H2O2) as oxidant, via a simple reaction protocol. Natural products are selectively oxidized and isolated in synthetically amenable yields. The easy access to large quantities of the catalyst and the simplicity of the C-H oxidation procedure make this system a particularly convenient tool to carry out alkane C-H oxidation reactions on the preparative scale, and in short reaction times.
Canta, Merce,Font, David,Gomez, Laura,Ribas, Xavi,Costas, Miquel
supporting information
p. 818 - 830
(2014/04/03)

Ultralight mesoporous magnetic frameworks by interfacial assembly of prussian blue nanocubes
A facile approach for the synthesis of ultralight iron oxide hierarchical structures with tailorable macro- and mesoporosity is reported. This method entails the growth of porous Prussian blue (PB) single crystals on the surface of a polyurethane sponge, followed by in situ thermal conversion of PB crystals into three-dimensional mesoporous iron oxide (3DMI) architectures. Compared to previously reported ultralight materials, the 3DMI architectures possess hierarchical macro- and mesoporous frameworks with multiple advantageous features, including high surface area (ca. 117 m2 g-1) and ultralow density (6-11 mg cm-3). Furthermore, they can be synthesized on a kilogram scale. More importantly, these 3DMI structures exhibit superparamagnetism and tunable hydrophilicity/hydrophobicity, thus allowing for efficient multiphase interfacial adsorption and fast multiphase catalysis.
Kong, Biao,Tang, Jing,Wu, Zhangxiong,Wei, Jing,Wu, Hao,Wang, Yongcheng,Zheng, Gengfeng,Zhao, Dongyuan
supporting information
p. 2988 - 2992
(2014/04/03)

Metal-free, mild, nonepimerizing, chemo- and enantio- or diastereoselective N-alkylation of amines by alcohols via oxidation/imine-iminium formation/reductive amination: A pragmatic synthesis of octahydropyrazinopyridoindoles and higher ring analogues
A mild step and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure has been developed via oxidation/imine-iminium formation/reduction cascade using TEMPO-BAIB-HEH-Bronsted acid catalysis in DMPU as solvent and a stoichiometric amount of amine. The optimized conditions were further extended for the nonenzymatic kinetic resolution of the chiral amine thus formed under nonenzymatic in situ hydrogen-transfer conditions using VAPOL-derived phosphoric acid (VAPOL-PA) as the Bronsted acid catalyst. The enantioselective cascade of the presented reaction was successfully utilized in the synthesis of octahydropyrazinopyridoindole and its higher ring analogues.
Khan, Imran A.,Saxena, Anil K.
p. 11656 - 11669
(2014/01/06)

C-H oxidation by H2O2 and O2 catalyzed by a non-heme iron complex with a sterically encumbered tetradentate N-donor ligand
The compound N,N′-dineopentyl-N,N′-bis(2-pyridylmethyl)-1,2- ethanediamine (dnbpn) and its ferrous complex [Fe(dnbpn)(OTf)2] were synthesized. The Fe(II) complex was used to catalyze the oxidation of hydrocarbons by H2O2 and O2. Although the catalyzed alkane oxidation by H2O2 displays a higher preference for secondary over tertiary carbons than those associated with most previously reported nonheme iron catalysts, the catalytic activity is markedly inferior. In addition to directing the catalyzed oxidation toward the less sterically congested C-H bonds of the substrates, the neopentyl groups destabilize the metal-based oxidants generated from H2O2 and the Fe(II) complex. The presence of benzylic substrates with weak C-H bonds stabilizes an intermediate which we have tentatively assigned as a high-spin ferric hydroperoxide species. The oxidant generated from O2 reacts with allylic and benzylic C-H bonds in the absence of a sacrificial reductant; less substrate dehydrogenation is observed than with related previously described systems that use O2 as a terminal oxidant.
Zhang, Qiao,Gorden, John D.,Goldsmith, Christian R.
p. 13546 - 13554
(2014/01/06)

Formation of quaternary stereogenic centers by copper-catalyzed asymmetric conjugate addition reactions of alkenylaluminums to trisubstituted enones
Alkenylaluminums undergo asymmetric copper-catalyzed conjugate addition (ACA) to β-substituted enones allowing the formation of stereogenic all-carbon quaternary centers. Phosphinamine-copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β-substituted enones. Two strategies for the generation of the requisite alkenylaluminums were explored allowing for the introduction of aryl- and alkyl-substituted alkenyl nucleophiles. Moreover, alkyl-substituted phosphinamine (SimplePhos) ligands were identified for the first time as highly efficient ligands for the Cu-catalyzed ACA. Chiral synthesis made easy: The copper-catalyzed conjugate addition of alkenylaluminum reagents to 3-substituted cyclic enones allows for the formation of all-carbon chiral quaternary centers (see scheme; CuTC=copper(I) thiophene-2-carboxylate). Chiral phosphinamine (SimplePhos) ligands were found to be highly efficient for this transformation.
Mueller, Daniel,Alexakis, Alexandre
supporting information
p. 15226 - 15239
(2013/11/06)

Catalyst-controlled aliphatic c-h oxidations with a predictive model for site-selectivity
Selective aliphatic C-H bond oxidations may have a profound impact on synthesis because these bonds exist across all classes of organic molecules. Central to this goal are catalysts with broad substrate scope (small-molecule-like) that predictably enhance or overturn the substrate's inherent reactivity preference for oxidation (enzyme-like). We report a simple small-molecule, non-heme iron catalyst that achieves predictable catalyst-controlled site-selectivity in preparative yields over a range of topologically diverse substrates. A catalyst reactivity model quantitatively correlates the innate physical properties of the substrate to the site-selectivities observed as a function of the catalyst.
Gormisky, Paul E.,White, M. Christina
supporting information
p. 14052 - 14055
(2013/10/21)

Site-selective oxidation of unactivated C sp 3-H bonds with hypervalent iodine(III) reagents
By design: The site-selective oxidation of unactivated secondary C sp 3-H bonds was accomplished with hypervalent iodine(III) reagents and tert-butyl hydroperoxide (see scheme). The preparation and derivatization of the hypervalent iodine(III) reagent are simple, thus allowing the rational design of these reagents to optimize the site selectivity of the oxidation. Copyright
Moteki, Shin A.,Usui, Asuka,Zhang, Tiexin,Solorio Alvarado, Cesar R.,Maruoka, Keiji
supporting information
p. 8657 - 8660
(2013/09/12)

Regioselective oxidation of nonactivated alkyl C-H groups using highly structured non-heme iron catalysts
Selective oxidation of alkyl C-H groups constitutes one of the highest challenges in organic synthesis. In this work, we show that mononuclear iron coordination complexes Λ-[Fe(CF3SO3) 2((S,S,R)-MCPP)] (Λ-1P), Δ-[Fe(CF3SO 3)2((R,R,R)-MCPP)] (Δ-1P), Λ-[Fe(CF 3SO3)2((S,S,R)-BPBPP)] (Λ-2P), and Δ-[Fe(CF3SO3)2((R,R,R)-BPBPP)] (Δ-2P) catalyze the fast, efficient, and selective oxidation of nonactivated alkyl C-H groups employing H2O2 as terminal oxidant. These complexes are based on tetradentate N-based ligands and contain iron centers embedded in highly structured coordination sites defined by two bulky 4,5-pinenopyridine donor ligands, a chiral diamine ligand backbone, and chirality at the metal (Λ or Δ). X-ray diffraction analysis shows that in Λ-1P and Λ-2P the pinene rings create cavity-like structures that isolate the iron site. The efficiency and regioselectivity in catalytic C-H oxidation reactions of these structurally rich complexes has been compared with those of Λ-[Fe(CF3SO3) 2((S,S)-MCP)] (Λ-1), Λ-[Fe(CF3SO 3)2((S,S)-BPBP)] (Λ-2), Δ-[Fe(CF 3SO3)2((R,R)-BPBP)] (Δ-2), Λ-[Fe(CH3CN)2((S,S)-BPBP)](SbF6) 2 (Λ-2SbF6), and Δ-[Fe(CH3CN) 2((R,R)-BPBP)](SbF6)2 (Δ-2SbF 6), which lack the steric bulk introduced by the pinene rings. Cavity-containing complexes Λ-1P and Λ-2P exhibit enhanced activity in comparison with Δ-1P, Δ-2P, Λ-1, Λ-2, and Λ-2SbF6. The regioselectivity exhibited by catalysts Λ-1P, Λ-2P, Δ-1P, and Δ-2P in the C-H oxidation of simple organic molecules can be predicted on the basis of the innate properties of the distinct C-H groups of the substrate. However, in specific complex organic molecules where oxidation of multiple C-H sites is competitive, the highly elaborate structure of the catalysts allows modulation of C-H regioselectivity between the oxidation of tertiary and secondary C-H groups and also among multiple methylene sites, providing oxidation products in synthetically valuable yields. These selectivities complement those accomplished with structurally simpler oxidants, including non-heme iron catalysts Λ-2 and Λ-2SbF6.
Gómez, Laura,Canta, Merceì,Font, David,Prat, Irene,Ribas, Xavi,Costas, Miquel
p. 1421 - 1433
(2013/03/29)

An iron catalyst for oxidation of alkyl C-H bonds showing enhanced selectivity for methylenic sites
Many are called but few are chosen: A nonheme iron complex catalyzes the oxidation of alkyl C-H bonds by using H2O2 as the oxidant, showing an enhanced selectivity for secondary over tertiary C-H bonds (see scheme). Copyright
Prat, Irene,Gomez, Laura,Canta, Merce,Ribas, Xavi,Costas, Miquel
supporting information
p. 1908 - 1913
(2013/03/14)

NEW TETRAHYDROPYRAZOLO[3,4-C]ISOQUINOLIN-5-AMINE DERIVATIVES
New tetrahydropyrazolo[3,4-c]isoquinolin-5-amine derivatives having the chemical structure of formula (I) are disclosed; as well as process for their preparation, pharmaceutical compositions comprising them and their use in therapy as inhibitors of the phosphodiesterase IV (PDE4).
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(2010/09/17)

SUBSTITUTED DIHYDRO AND TETRAHYDRO OXAZOLOPYRIMIDINONES, PREPARATION AND USE THEREOF
The present invention relates to a series of substituted dihydro and tetrahydro oxazolopyrimidinones, specifically, to a series of 2-substituted-2,3-dihydro-oxazolo[3,2-a]pyrimidin-7-ones and 2-substituted-2,3,5,6-tetra-hydro-oxazolo[3,2-a]pyrimidin-7-ones of formula (I): Wherein p, n, X, Y, R1, R2, R3, R4, R5, R6, R7 and R8 are as defined herein. This invention also relates to methods of making these compounds including novel intermediates. The compounds of this invention are modulators of metabotropic glutamate receptors (mGluR), particularly, mGluR2 receptor. Therefore, the compounds of this invention are useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of central nervous system disorders (CNS), including but not limited to acute and chronic neurodegenerative conditions, psychoses, convulsions, anxiety, depression, migraine, pain, sleep disorders and emesis.
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(2010/04/23)

Combined effects on selectivity in Fe-catalyzed methylene oxidation
Methylene C-H bonds are among the most difficult chemical bonds to selectively functionalize because of their abundance in organic structures and inertness to most chemical reagents. Their selective oxidations in biosynthetic pathways underscore the power of such reactions for streamlining the synthesis of molecules with complex oxygenation patterns. We report that an iron catalyst can achieve methylene C-H bond oxidations in diverse natural-product settings with predictable and high chemo-, site-, and even diastereoselectivities. Electronic, steric, and stereoelectronic factors, which individually promote selectivity with this catalyst, are demonstrated to be powerful control elements when operating in combination in complex molecules. This small-molecule catalyst displays site selectivities complementary to those attained through enzymatic catalysis.
Chen, Mark S.,White, M. Christina
scheme or table
p. 533 - 571
(2010/10/05)

SYNTHESIS OF GREEN KETONE INTERMEDIATE
A process for the preparation of 1-ethynyl-3,3-dimethylcyclohexan-1-ol from dimedone by a reaction sequence of reduction and ethynylation and its further transformation into green ketone.
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(2010/04/30)

Strain release in C-H bond activation?
What a relief ! In 1955, strain release was put forward as a reactivity factor to explain the differing reactivity of axial and equitorial alcohols during oxidation. The same rationale may account for the differing rates of activation between axial and equitorial C-H bonds in C-H activation processes (see scheme)
Chen, Ke,Eschenmoser, Albert,Baran, Phil S.
supporting information; experimental part
p. 9705 - 9708
(2010/04/28)

Synthesis of mono-ketones from 1,3-diketones
The present invention is directed to a process for the manufacture of a mono-ketone comprising the step of hydrogenating a 1,3-diketone with hydrogen in the presence of a bifunctional catalyst having an acid functionality and a hydrogenation functionality.
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(2009/12/23)

Synthesis of (±)-ar-macrocarpene
An efficient first synthesis of the sesquiterpene ar-macrocarpene, an irregular sesquiterpene isolated from Cupressus macrocarpa foliage, starting from 3-methylcyclohexenone has been described, which confirmed the structures of macrocarpenes. Copyright Taylor & Francis Group, LLC.
Srikrishna,Beeraiah
p. 2855 - 2860
(2008/03/11)

NEW PYRIDO[3',2':4,5]FURO[3,2-d]PYRIMIDINE DERIVATIVES
The present invention provides a pyridofuropyrimidine derivative of formula (I): wherein G1 represents a group selected from -CR6R7- and -O- wherein R6 and R7 independently represent hydrogen atoms or C1-4 alkyl groups; R1 and R2 are independently selected from hydrogen atoms and C1-4 alkyl groups; R3 represents a group selected from C1-4 alkyl, C1-4 alkoxy, amino, hydroxy, mono- C1-4 alkylamino, di- C1-4 alkylamino, C3-8 cycloalkylamino, aryl, heteroaryl and saturated N-containing heterocyclyl groups which are bound to the pyridine ring through their nitrogen atom, all of them being optionally substituted by one or more substituents selected from the group consisting of halogen atoms and hydroxy, C1-4 alkyl, C1-4 alkoxy- C1-4 alkyl, aryl-C1-4 4alkyl, -O(CO)O R8, C1-4 alkoxy, -(CO)NR8R9, -CN, -CF3, -NR8R9, -SR8 and -SO2NH2 groups wherein R8 and R9 each independently represent a hydrogen atom or a C1-4 alkyl group; R4 and R5 are independently selected from the group consisting of hydrogen atoms, C1-4 alkyl groups, hydroxyl- C1-4 alkyl groups and groups of formula (II): wherein p and q are integers selected from 0, 1 , 2 and 3; A is either a direct bond or a group selected from -CONR14-, -NR14CO-, -0-, -COO-, -OCO-, -S-, -SO- and -SO2-, wherein each R10, R11, R12, R13 and R14 independently represents a hydrogen atom or a C1-4 alkyl group and G2 is a group selected from aryl, heteroaryl or heterocyclyl groups; wherein the group G2 is optionally substituted by one or more substituents selected from group consisting of halogen atoms and C1-4 alkyl, hydroxy, oxo, C1-4 alkoxy- C1-4 alkyl, aryl- C1-4 alkyl, -(CO)OR16, C1-4 alkoxy, -(CO)NR16R17, -CN, -CF3, -NR16R17, -SR16 and -SO2NH2 groups; wherein R16 and R17 each independently represent a hydrogen atom or a C1-4 alkyl group and the pharmaceutically acceptable salts and N-oxides thereof.
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(2010/11/25)

NEW PYRIDOTHIENOPYRIMIDINE DERIVATIVES
Use of a pyridothienopyrimidine derivative of formula (I), and the pharmaceutically acceptable salts and N-oxides thereof, wherein G1 represents a group selected from -CR6R7- or -NR6 being R6 and R7 independently selected from hydrogen atoms and C1-4 alkyl groups m and n are integers selected from 0 or 1 R1 and R2 are independently selected from hydrogen atoms and C1-4 alkyl groups R3 represents a group selected from alkyl, amino, monoalkylamino, dialkylamino, aryl, heteroaryl and saturated N-containing heterocyclyl groups bound through the nitrogen atom to the piridine ring, all of them being optionally substituted by one or more substituents selected from the group consisting of halogen atoms and alkyl, alkoxyalkyl, arylalkyl, R8OCO-, alkoxy, R8R9N-CO-, -CN, -CF3, -NR8R9, -SR8 and - SO2NH2 groups wherein R8 and R9 are independently selected from hydrogen atoms and C1-4alkyl groups R4 and R5 are independently selected from the group consisting of hydrogen atoms alkyl groups and groups of formula (II), wherein p and q are integers selected from 1, 2 and 3; A is either a direct bond or a group selected from -CONR14-, -NR14CO-, -O-, -COO-, -OCO-, -NR 14OCO-, - OCONR14-, -NR14CONR15-, -S-, -SO-, -SO2-, -COS- and -SCO-; and G2 is a group selected from aryl, heteroaryl or heterocyclyl; wherein the alkyl groups and the group G2 are optionally substituted by one or more substituents selected from group consisting of halogen atoms and alkyl, alkoxyalkyl, arylalkyl, R16OCO-, hydroxy, alkoxy, oxo, R16R17NCO-, -CN, -CF3, -NR16R17,-SR16 and -SO2NH2 groups; wherein R10 to R17 are independently selected from hydrogen atoms and C1-4 alkyl groups; in the manufacture of a medicament for the treatment or prevention of a pathological condition or disease susceptible to amelioration by inhibition of phosphodiesterase 4.
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(2008/06/13)

Nucleophilic substitution reactions of sulfur-substituted cyclohexanone acetals: An analysis of the factors controlling stereoselectivity
The reactions of cyclohexanone acetals substituted with thiophenyl groups (and other heteroatoms) at C-2 demonstrate the powerful influence that these substituents have on the stereoselectivity of nucleophilic substitution reactions. The trans selectivities of these reactions correlate with the behavior of the corresponding ketones. These experiments lend support to the possibility that the reactions of the acetals, which proceed via oxocarbenium ions, are operating under Felkin-Anh control.
Billings, Susan B.,Woerpel
p. 5171 - 5178
(2007/10/03)

Niacin receptor agonists, compositions containing such compounds and methods of treatment
The present invention encompasses compounds of Formula I: as well as pharmaceutically acceptable salts and hydrates thereof, that are useful for treating atherosclerosis, dyslipidemias and the like. Pharmaceutical compositions and methods of use are also included.
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Page/Page column 31; 52

(2010/11/25)

Synthesis and structure-affinity relationships of 1,3,5-alkylsubstituted cyclohexylamines binding at NMDA receptor PCP site
A series of 1,3,5-alkylsubstituted cyclohexylamines 2 were synthesized as ligands for the N-methyl-D-aspartate (NMDA) receptor phencyclidine (PCP) binding site. Pure diastereomers with defined configuration of amino group 2- ax and 2-eq were obtained. The optimal size of 1,3,5-substituents was determined for cyclohexylamines 2 with an equatorial amino group in the lowest energy conformation using Hansch analysis. According to the data, the lipophilic part of cyclohexylamines 2 does not discriminate between hydrophobic regions of the PCP binding site but rather recognizes this site as a whole lipophilic pocket. (C) 2000 Editions scientifiques et medicales Elsevier SAS.
Jirgensons, Aigars,Kauss, Valerjans,Kalvinsh, Ivars,Gold, Markus R.,Danysz, Wojciech,Parsons, Chris G.,Quack, Gunter
p. 555 - 565
(2007/10/03)

Amidino derivatives useful as nitric oxide synthase inhibitors
The current invention discloses useful pharmaceutical compositions containing amidino derivative useful as nitric oxide synthase inhibitors.
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(2008/06/13)

Substituted cyclic amino acids as pharmaceutical agents
PCT No. PCT/US97/02295 Sec. 371 Date May 20, 1998 Sec. 102(e) Date May 20, 1998 PCT Filed Feb. 18, 1997 PCT Pub. No. WO97/33858 PCT Pub. Date Sep. 18, 1997Substituted cyclic amino acids of formula are disclosed and are useful as agents in the treatment of epilepsy, faintness attacks, hypokinesia, cranial disorders, neurodegenerative disorders, depression, anxiety, panic, pain, and neuropathological disorders. Processes for the preparation and intermediates useful in the preparation are also disclosed.
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(2008/06/13)

Alkylating agent and 1,4-addition process of an alkyl group onto an α,β-unsaturated ketone compound
Disclosed is an alkylating agent that contains an aluminum reagent Alk3-m AlLm, in which Alk means a methyl, ethyl, n- or i-propyl, n-, i- or tert-butyl, pentyl, hexyl, heptyl or octyl group, which all can also be branched, L means an ethoxy group, a chlorine or bromine atom, and m is equal to 1 or 2, as an alkyl source or else zinc dimethyl as a methyl source, which contains in addition catalytic amounts of one or more copper(I) and/or copper(II) compounds and one (or more) silyl reagent(s) of general formula III in which R1, R2 and R3 are as defined herein, as well as a process for 1,4-addition of an alkyl group to an α,β-unsaturated ketone or an α,β-double unsaturated ketone or to an α,β-unsaturated aldehyde with use of the agent according to the invention. The alkylating agent yields biologically active compounds in excellent yields and the new alkylating agent/process is distinguished by its environmental compatibility based on a CKW (chlorinated hydrocarbon)-free reaction medium.
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(2008/06/13)

Amidino dervatives useful as nitric oxide synthase inhibitors
The current invention discloses useful pharmaceutical compositions containing azepine derivatives useful as nitric oxide synthase inhibitors.
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(2008/06/13)

Photoinduced Electron Transfer Reactions of α-Cyclopropyl- And α-Epoxy Ketones. Tandem Fragmentation-Cyclization to Bi-, Tri-, and Spirocyclic Ketones
Reductive photoinduced electron transfer (PET) reactions have been performed with various bicyclic a-cyclopropyl-substituted ketones and tertiary amines. The reaction resulted in a regioselective cleavage of one cyclopropyl bond under formation of an exocyclic radical with an endocyclic enolate unit. In the case of bicyclic ketones with an unsaturated side chain, various bicyclic, spirocyclic, and tricyclic products are accessible via radical cyclization, depending on the position of the alkenyl substituent. In addition to triethylamine, W-silylated amines have also been used as electron donors, leading to a variety of compounds, among them are silylated fragmentation products, indicating that a proton is transferred from not only the amine radical cation but also the cationic silyl group. The intramolecular Paternoe-Buechi reaction has also been studied for cyclopropane derivatives of the jasmone type leading to tetracyclic oxetanes. Finally, α-epoxy-substituted ketones have been investigated under PET conditions, yielding ring-opened products.
Kirschberg, Thorsten,Mattay, Jochen
p. 8885 - 8896
(2007/10/03)

Radical formation in the oxidation of 2,2′-azo-2-methyl-6-heptene by thianthrene cation radical
Reaction of 2,2′-azo-2-methyl-6-heptene (1) with thianthrene cation radical perchlorate (Th?+ClO4-) in CH2Cl2 solution containing 2,6-di-tert-butyl-4-methylpyridine (DTBMP) gave a mixture of nine C8 hydrocarbons, namely, 1,1,2-trimethylcyclopentane (4, 2.2%), 6-methyl-1-heptene (5, 2.2%), 2-methyl-1,6-heptadiene (6, 9.8%), 2,2-dimethyl-1-methylenecyclopentane (7, 2.9%), 6-methyl-1,5-heptadiene (8, 39%), 3,3-dimethyl- (9, 7.6%), 4,4-dimethyl- (10, 11%), 1,2-dimethyl- (11, 5.4%), and 1,6-dimethylcyclohexene (12, 1.5%). The amounts of acyclic dienes (6, 8) fell and of cyclohexenes (9, 10) rose when DTBMP was omitted from or diminished in the solution. The results provide firm evidence (products 4, 5, and 7) for the formation of the 2-methyl-6-hepten-2-yl radical (2), although the major fate of 2 is its oxidation to the corresponding cation 13, the origin of the bulk of the other products.
Chen, Tonghua,Shine, Henry J.
p. 4716 - 4719
(2007/10/03)

The Kharasch reaction revisited: CuX3Li2-catalyzed conjugate addition reactions of Grignard reagents
The conjugate addition of Grignard reagents RMgX to α,β-unsaturated ketones and esters is effectively catalyzed by soluble copper ate-complexes of the type CuX3Li2, e.g.CuI*2LiCl.In the presence of Me3SiCl the corresponding ketone enolsilanes are formed in high yield and selectivity.Diastereoselectivity in the case of chiral ketones is similar to that observed by using stoichiometric amounts of cuprates R2CuLi.Thus CuX3Li2-catalyzed 1,4-additions of Grignard reagents may be an industrially viable process.Keywords: Copper; Magnesium; Lithium; Silicon; Ketone; Enolsilanes
Reetz, Manfred T.,Kindler, Alois
p. C5 - C7
(2007/10/02)

The mechanism of organocuprate 1,4-addition reactions with αβ-unsaturated ketones: Formation of cuprate-enone complexes with lithium dimethylcuprate
Colored complexes can be obtained from some enones on addition to ethereal Me2CuLi-LiI at -78°C. The unreacted enone can be recovered from these mixtures in high yield by low-temperature protonation. When 2,2,5-trimethyl-4-hexen-3-one was added to Me2CuLi-LiI at -80°C, cuprate-olefin and lithium-carbonyl complexes were formed and observed by 13C NMR. On warming this reaction solution to -55°C, only the lithium-carbonyl complex was detectable which slowly (t1/2 ≈ 2.5 h) converted into the β-alkylated enolate. Implications of these observations on the description of the mechanism of the 1,4-addition reaction are presented.
Vellekoop, A. Samuel,Smith, Robin A. J.
p. 2902 - 2913
(2007/10/02)

Kupferkatalysierte 1,4-Additionen von Trialkylaluminiumverbindungen an Enone
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Westermann, Juergen,Nickisch, Klaus
p. 1429 - 1431
(2007/10/02)

Bicyclo[3.3.1]nonane approach to triquinanes. Formal synthesis of (+/-)Δ(9(12))capnellene and [+/-)Δ(9(12))capnellene-8-β-10α-diol
A new synthetic strategy for natural triquinanes is presented as a model study. Stereospecific rearrangement of the ready accessible bicyclo[3.3.1]nonanic acetoxychloride 6 gave the cis-pentalanic hydroxyaldehyde 5, which has been converted into the ketone 4 already reported as a key intermediate in some syntheses of the title capnellenes.
Gambacorta,Fabrizi,Bovicelli
p. 4459 - 4464
(2007/10/02)

Reactions of Cyclohexane Derivatives in Superacids
The reactions of menthol with FSO3H-SO2 and neomenthyl chloride with SbF5-SO2ClF follow different routes.The first yields a substituted cyclopentyl cation and the second a substituted cyclohexyl cation.Experiments on substituted cyclohexyl chlorides show that replacement of all the hydrogen atoms on the next but one carbon atom to the reaction centre blocks formation of a carbocation.It is suggested that ionisation of an equatorial chlorine atom takes place with assistance from an intramolecular electronic interaction, forming the methyl cyclopentyl carbocation in a synchronous process, rather than stepwise via the cyclohexyl carbocation.Reasons for contrasting behaviour in solvolytic reactions are discussed.
Dean, Christopher,Whittaker, David
p. 1541 - 1543
(2007/10/02)

ORGANOMANGANESE (II) REAGENTS XVI: COPPER-CATALYZED 1,4-ADDITION OF ORGANOMANGANESE CHLORIDES TO CONJUGATED ENONES
Copper-catalyzed conjugate addition of organomanganese chlorides to conjugated enones in THF, at 0 deg C, leads to the 1,4-addition products in high yields.The scope of the reaction is very large and the results are generally better than those obtained from organomagnesium compounds in the presence of a copper salts as well as from organocopper or cuprate reagents.Furthermore organomanganese chlorides are indisputably cheaper and more stable than the latter.
Cahiez, Gerard,Alami, Mouad
p. 3541 - 3544
(2007/10/02)

The Role of BF3*Et2O in Reactions of Lower Order (Gilman) Organocuprates
The effects of BF3*Et2O on lower order organocuprate reactions in THF have been investigated so as to determine what factors are responsible for the oftentimes dramatic reaction-rate enhancements observed.From spectroscopic experiments on the reagents alone, supported further by chemical studies, it was found that an orginally formed cuprate (R2CuLi or RR'CuLi) is altered significantly upon exposure to this Lewis acid.The copper-containing species thereby generated, together with BF3, form a more reactive combination and appear to be at least in part responsible forthe accelerated chemistry.
Lipshutz, Bruce H.,Ellsworth, Edmund L.,Siahaan, Teruna J.
p. 1351 - 1358
(2007/10/02)

Conjugate Reduction of α,β-Unsaturated Ketones with Amphiphilic Reaction System
The conjugate reduction of α,β-unsaturated ketones has been effected with amphiphilic reaction system consisting of methylaluminum bis(2,6-di-t-butyl-4-alkylphenoxide) and certain complex aluminum hydride reagent.
Nonoshita, Katsumasa,Maruoka, Keiji,Yamamoto, Hisashi
p. 2241 - 2243
(2007/10/02)

CATALYTIC HYDROGENATION OF DIKETONES
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Cormier, Russell A.,McCauley, Mark D.
p. 675 - 676
(2007/10/02)

STUDIES ON THE REDUCTION OF CYCLIC 1,3-DIKETONES VIA THEIR TRIFLATES
Using 1,3-Cyclohexadione (1) and 5,5-dimethyl-1,3-Cyclohexadione (11) as examples, it is shown that 1,3-diketones can be transformed into monoketones, monoalcohols, alkanes and unsaturated ketones.
Martinez, A. Garcia,Alvarez, R. Martinez,Casado, M. Madueno,Subramanian, L. R.,Hanack, M.
p. 275 - 280
(2007/10/02)