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Synthesis, characterization, crystal structure, and antimicrobial studies of 2-morpholinoethyl-substituted benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes
This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and their Ag(I) N-heterocyclic carbene (NHC) complexes (3a–c). All compounds were characterized by 1H and 13C Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), and elemental analysis, and their antimicrobial effects examined. The molecular structure of the NHC precursor 2a1 was established by single-crystal X-ray diffraction analysis. Minimum Inhibition Concentration (MIC) values were determined to evaluate their antimicrobial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacterial strains and Candida albicans fungal species. All tested samples were compared with silver nitrate. All the compounds exhibited strong antimicrobial activity.
Y?ld?r?m, I??l,Akta?, Ayd?n,Celepci, Duygu Barut,K?rba?, Sevda,Kutlu, Türkan,G?k, Yetkin,Aygün, Muhittin
p. 6379 - 6393
(2017)
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Induced Fitting and Polarization of a Bromine Molecule in an Electrophilic Inorganic Molecular Cavity and Its Bromination Reactivity
Dodecavanadate, [V12O32]4? (V12), possesses a 4.4 ? cavity entrance, and the cavity shows unique electrophilicity. Owing to the high polarizability, Br2 was inserted into V12, inducing the inversion of one of the VO5 square pyramids to form [V12O32(Br2)]4? (V12(Br2)). The inserted Br2 molecule was polarized and showed a peak at 185 cm?1 in the IR spectrum. The reaction of V12(Br2) and toluene yielded bromination of toluene at the ring, showing the electrophilicity of the inserted Br2 molecule. Compound V12(Br2) also reacted with propane, n-butane, and n-pentane to give brominated alkanes. Bromination with V12(Br2) showed high selectivity for 3-bromopentane (64 %) among the monobromopentane products and preferred threo isomer among 2-,3-dibromobutane and 2,3-dibromopenane. The unique inorganic cavity traps Br2 leading the polarization of the diatomic molecule. Owing to its new reaction field, the trapped Br2 shows selective functionalization of alkanes.
Hayashi, Yoshihito,Inada, Yasuhiro,Katayama, Misaki,Kikukawa, Yuji,Kitajima, Hiromasa,Seto, Kensuke,Watanabe, Daiki,Yamashita, Shohei
supporting information
p. 14399 - 14403
(2020/07/13)

Sulfonyl halide synthesis by thiol oxyhalogenation using NBS/NCS – iPrOH
A rapid and facile method provides a general route to sulfonyl bromides/chlorides by the oxidation of thiols using NXS – ROH (X?=?Br,Cl, R?=?iPr) as an oxyhalogenation reagent. Control experiments suggest that the alcohol component is the source of oxygen. The proposed method enable the access to structurally diverse sulfonyl bromides and chlorides including challenging examples, inaccessible by other synthetic methods.
Silva-Cuevas, Carolina,Perez-Arrieta, Carlos,Polindara-García, Luis A.,Lujan-Montelongo, J. Armando
p. 2244 - 2247
(2017/05/16)

METHODS AND COMPOSITIONS FOR TREATING HIV-RELATED DISORDERS
Certain adjunctive therapies comprising a kynurenine-3-monooxygenase inhibitor and an antiviral agent for treating HIV-related disorders are provided herein. These disorders include AIDS dementia complex, AIDS-induced encephalopathy, HIV-associated neurocognitive disorder, asymptomatic neurocognitive impairment, minor neurocognitive disorder, minor cognitive motor disorder, vacuolar myelopathy, peripheral neuropathies, and polymyositis. Also provided are pharmaceutical compositions comprising a kynurenine-3- monooxygenase inhibitor and an antiviral agent.
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Paragraph 0213

(2016/02/10)

Ruthenium bipyridyl tethered porous organosilica: A versatile, durable and reusable heterogeneous photocatalyst
A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides. This journal is
Jana, Avijit,Mondal, John,Borah, Parijat,Mondal, Sujan,Bhaumik, Asim,Zhao, Yanli
supporting information
p. 10746 - 10749
(2015/06/30)

On the mechanism of the palladium bis(NHC) complex catalyzed CH functionalization of propane: Experiment and DFT calculations
We report a detailed mechanistic study on the CH functionalization of alkanes by palladium complexes with chelating bis(N -heterocyclic carbene) (NHC) complexes. The experimental results are complemented by detailed DFT calculations, which allow us to rationalize the regioselectivity and the catalytic activity. The study includes a library of catalysts with different electronic and steric properties, kinetic data, and isotope effects. The combined experimental and computational results favor a mechanism involving organometallic palladium(IV) intermediates. Furthermore, it is shown that at high halide loadings a different mechanism is operative.
Munz, Dominik,Strassner, Thomas
p. 14872 - 14879
(2015/04/16)

Synthesis of an H3 antagonist via sequential one-pot additions of a magnesium ate complex and an amine to a 1,4-ketoester followed by carbonyl-directed fluoride addition
We describe the development of an efficient and scalable process for the preparation of fluorocyclobutane-containing H3 antagonist, 1. The synthesis was accomplished by the chemoselective addition of a magnesium ate complex and an amine to a 1,4-ketoester in a one-pot sequence, followed by a diastereoselective carbonyl-directed fluorination. The chemoselective addition of the magnesium ate complex to the ketoester benefited from tight stoichiometric control, short addition times, and lower reaction temperatures, and thus was amenable to rapid mixing and excellent heat transfer in a flow reactor.
Hawkins, Joel M.,Dube, Pascal,Maloney, Mark T.,Wei, Lulin,Ewing, Marcus,Chesnut, Stephen M.,Denette, Joshua R.,Lillie, Brett M.,Vaidyanathan, Rajappa
p. 1393 - 1403
(2012/11/07)

CONTINUOUS PROCESS FOR CONVERTING NATURAL GAS TO LIQUID HYDROCARBONS
A method comprising: providing a first halogen stream; providing a first alkane stream; reacting at least a portion of the first halogen stream with at least a portion of the first alkane stream in a first reaction vessel to form a first halogenated stream; providing a second alkane stream comprising C2 and higher hydrocarbons; providing a second halogen stream; and reacting at least a portion of the second halogen stream with at least a portion of the second alkane stream in a second reaction vessel to form a second halogenated stream.
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Page/Page column 66-67

(2010/04/03)

METHODS OF REMOVING IMPURITIES FROM ALKYL BROMIDES DURING DISTILLATION AND DISTILLATE PRODUCED THEREBY
Methods are provided for removing impurities from compositions comprising alkyl bromide. Such methods comprise combining such composition with at least one nonvolatile epoxide during distillation to purify the alkyl bromide. Ultra pure alkyl bromide compositions are also provided.
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Page/Page column 6; 7

(2009/05/29)

Highly efficient direct carboxylation of propane into butyric acids catalyzed by vanadium complexes
A direct and highly efficient carboxylation of propane by carbon monoxide into butyric acids (mainly isobutyric and, in a smaller amount, n-butyric), in the presence of potassium peroxodisulphate (K2S2O 8) and in trifluoroacetic acid solution, has been achieved by using a vanadium catalytic system based on Ca[V{ON(CH(CH3)COO) 2}2] (synthetic amavadine), its model compounds Ca[V{ON-(CH2COO)2}2] or [VO(N(CH 2CH2O)3}] - other simpler vanadium compounds, such as [VO(acac)2] or VOSO4, are less active. Overall yields (based on pro- ane) of carboxylic acids up to 70% and TON values up to 18.4 × 103 have been reached. The effects of various factors such as the propane and carbon monoxide pressures, temperature, time, catalyst amount and radical traps have been investigated, the reactions are shown to proceed via both C- and O-centred radicals, with K2S 2O8 playing the role of an oxidant via a free radical mechanism.
Kirillova, Marina V.,Da Silva, Jose A. L.,Da Silva, Joao J. R. Frausto,Palavra, Antonio F.,Pombeiro, Armando J. L.
p. 1765 - 1774
(2008/02/11)

PROCESSES FOR PRODUCTION AND PURIFICATION OF NORMAL PROPYL BROMIDE
A process for oxygen-initiated hydrobromination of propene to form a crude reaction mixture of 95 GC area % n-propyl bromide. The process includes feeding an oxygen-containing gas, propene and hydrogen bromide into a liquid phase mixture comprised of n-propyl bromide and hydrogen bromide. At least the oxygen-containing gas and the propene of the feed are fed subsurface to the liquid phase mixture and either (a) the oxygen-containing gas and the propene do not come together in the absence of hydrogen bromide or (b) the oxygen-containing gas and the propene come together only in a propene:oxygen molar ratio in the range of 145:1 to 180:1. Purification processes provide a propyl bromide product containing at least 99.7 GC area % n-propyl bromide. Also provided is a novel composition of enhanced thermal stability which comprises a mixture of n-propyl bromide and isopropyl bromide. The mixture has an n-propyl bromide content of at least 99.7 GC area %, and an isopropyl bromide content of no more than 0.05 GC area %. The mixture, if subjected to storage in a closed chemically inert container at 60°C for at least 480 hours, has an APHA color of 10 or less while the mixture is devoid of any added stabilizer component.
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Page/Page column 21; 22

(2008/06/13)

2-OXO-ETHANESULFONAMIDE DERIVATES
Compounds of formula (I): Formula (I) wherein variable groups are as defined within; for use in the inhibition of 11betaHSD1 are described.
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Page/Page column 49

(2010/02/07)

Oligocycloalkanoid compounds and methods of use
The present invention related to an oligocycloalkanoid compound comprising formula (I) wherein m, n, and o are independently an integer from 0 to 2; A1through A10are independently a direct link, alkylene, alkylene-O—, carbonyl, oxygen, or sulfur; X and Y are independently hydrogen, hydroxy, alkyl, or in combination an electrophilic group; and R1through R10are independently hydrogen, hydroxy, alkyl, alkenyl, alkynyl, substituted or unsubstituted aryl, N-, S-, or O-heterocycles, fused or multi-ring aryl with or without hetero ring members, arylalkyl, arylalkenyl, arylalkynyl, alkylphenyl, alkenylphenyl, alkynylphenyl, alkoxy, alkenyloxy, alkynyloxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkoxy, alkylacyl, alkenylacyl, alkynylacyl, arylacyl, aroyl, alkylaroyl, aminoaroyl, aminoalkylacyl, aminoalkyl, aminoalkenyl, aminoalkynyl, amino, alkylamino, alkenylamino, alkynylamino, arylamino, dialkylamino, dialkenylamino, dialkynylamino, arylalkylamino, arylalkenylamino, imino, alkylimino, alkenylimino, alkynylimino, arylimino, thiol, sulfoxide, alkyl sulfonamide, alkenyl sulfonamide, alkynyl sulfonamide, aryl sulfonamide, alkyl sulfonate ester, alkenyl sulfonate ester, alkynyl sulfonate ester, aryl sulfonate ester, amino acid, or polypeptide, with at least one of R1through R4and at least one of R7through R10being other than hydrogen. Also disclosed are a pharmaceutical composition including an oligocycloalkanoid compound of the present invention, and methods of using such compounds or compositions for treating a bacterial infection, inhibiting or treating septic shock, treating a disease caused by bacterial endotoxin, and inhibiting the activity of cathepsin K.
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(2008/06/13)

Process for functionalising a phenolic compound carrying an electron-donating group
The invention concerns a method for functionalizing a phenolic compound bearing an electron-donor group, in said group para position, inter alia a method for the amidoalkylation of a phenolic compound bearing an electron-donor group, and more particularly, a phenolic compound bearing an electron-donor group preferably, in the hydroxyl group ortho position. The method for functionalizing in para position with respect to an electron-donor group carried by a phenolic compound is characterised in that the phenolic compound bearing an electron-donor group is subjected to the following steps: a first step which consists of protecting the hydroxyl group in the form of a sulphonic ester function; a second step which consists in reacting the protected phenolic compound with an electrophilic reagent; optionally, a third step deprotecting the hydroxyl group.
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(2008/06/13)

Triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone as a new, selective and neutral system for the facile conversion of alcohols, thiols and selenols to alkyl halides in the presence of halide ions
A mixture of triphenylphosphine (Ph3P) and 2,3-dichloro-5,6-dicyanobenzoquinone in CH2Cl2 affords a complex which in the presence of R4NX (X=Cl, Br, I) converts alcohols, thiols and selenols into their corresponding alkyl halides in high yields at room temperature. The method is highly selective for the conversion of 1° alcohols in the presence of 2° ones and also 1° and 2° alcohols in the presence of 3° alcohols, thiols, epoxides, trimethylsilyl- and tetrahydropyranyl ethers, 1,3 dithianes, disulfides, and amides.
Iranpoor,Firouzabadi,Aghapour,Vaez zadeh
p. 8689 - 8693
(2007/10/03)

Triazole derivatives
The present invention relates to triazole and imidazole derivatives of formula I and to their pharmaceutically acceptable acid addition salts. These compounds are NMDA receptor subtype blockers and are useful for the treatment of diseases related to the NMDA receptor.
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(2011/03/17)

Two-fragment α-adrenolytics 4. Synthesis of phosphorylated derivatives of 2-aryloxyethylamines and N-phenylpiperazine
The reactions of 3-chloropropylphosphonates, 3-chloropropylthiophosphonates, or 3-chloropropylphosphinates with 2-aryloxyethylamines or N-phenylpiperazine afford the corresponding 3-(2-aryloxyethylamino)propylphosphonates and -phosphinates or 3-(4-phenylpiperazin-1-yl)propylphosphonates and -phosphinates. The compounds obtained exhibit α-adrenolytic and hypotensive activities, the latter being found to depend on the substituents at the P atom.
Reznik,Akamsin,Galyametdinova
p. 125 - 129
(2007/10/03)

A facile conversion of thiols to alkyl halides by triphenylphosphine/N-halosuccinimides
Thiols are efficiently converted to alkyl halides in high to excellent yields when treated with triphenylphosphin/N-halosuccinimide (halogen: Br,Cl, and I) in dichloromethane at room temperature.
Iranpoor,Firouzabadi,Aghapour
p. 1176 - 1178
(2007/10/03)

Esterification of carboxylic acid salts
Mono- or polycarboxylic acid esters are prepared by reacting a salt of such carboxylic acid with an organic halocompound, e.g., a (cyclo)alkyl, (cyclo)alkenyl, aryl or aralkyl halide, in an aqueous reaction medium, in the presence of a catalytically effective amount of a phase transfer catalyst, for example an onium salt.
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(2008/06/13)

The enzymatic synthesis of isotopically labelled penicillin Ns with isopenicillin N synthase
The preparation of isotopically labelled penicillin Ns using a chemico-enzymatic approach is described. This route involves the chemical synthesis of variously labelled D,L,D,-aminoadipoyl-cysteinyl-valine tripeptides via well established facile protocols and concludes with the conversion of these tripeptides directly into penicillin Ns by the action of recombinant isopenicillin N synthase. Milligram quantities of isotopically labelled penicillin Ns, which would otherwise represent very challenging and expensive synthetic targets, are readily accessible from this route.
Baldwin, Jack E.,Adlington, Robert M.,Crouch, Nicholas P.,Pereira, Ines A.C.
p. 1145 - 1163
(2007/10/03)

Functionalization of saturated hydrocarbons by aprotic superacids 4. Ionic bromination of ethane and other alkanes and cycloalkanes with molecular bromine in the presence of systems based on polyhalomethanes and AlBr3 under mild conditions
Aprotic organic superacids CBr4 · 2AlBr3, CBr4 · AlBr3, · CCl4 · 2AlBr3, CCl4 · 2AlBr3, and C6F5CF3 · 2AlBr3 efficiently catalyze the bromination of alkanes and cycloalkanes with Br2. Ethane is selectively brominated at 55-65 °C to give mostly 1,2-dibromoethane (stoichiometric reaction). Propane, butane, cyclopentane, cyclohexane, and methyl-cyclopentane react with Br2 at -40 to -20 °C with good selectivity affording monobromides in high yields (catalytic reactions).
Akhrem,Orlinkov,Afanas'eva,Vol'pin
p. 1148 - 1153
(2007/10/03)

Ionic Bromination of Ethane and Other Alkanes (Cycloalkanes) with Bromine Catalyzed by the Polyhalomethane*2AlBr3 Aprotic Organic Superacids under Mild Conditions
The polyhalomethane*2AlBr3 aprotic organic superacids were shown to effectively catalyze low-temperature ionic bromination of (cyclo)alkanes.Ethane readily reacts with Br2 at 55-65 deg C, affording mainly 1,2-dibromoethane.Propane, butane, and C5-C6 cycloalkanes react at -40 - -20 deg C, resulting in monobromides with high yields and good selectivity.
Akhrem, Irena S.,Orlinkov, Alexander V.,Afanas'eva, Lyudmila V.,Mysov, Evgenii I.,Vol'pin, Mark E.
p. 9365 - 9368
(2007/10/02)

Chroman derivatives
Chroman derivatives of the formula I STR1 wherein R1 to R8 have the meanings defined herein, and their salts have an effect on the cardiovascular system.
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(2008/06/13)

Activation of the silicon-halogen bond by bismuth (III) halides. Halogenation of alcohols: prospective and mechanism
In the presence of catalytic amount of BiCl3, chloromethylsylanes can be used as chlorinating agents for alcohols, and as chloro-dealkylating agents for silyl ethers and carboxylic and sulfonic esters.The chlorination of (R)-(-)-octan-2-ol and the (R)-(-)-2-mesyloctane by TMSCl gave predominantly the (S)-(+)-2-chlorooctane with inversion of configuration at secondary carbon.According to the class of alcohol, the mechanism involves SN2, SN2' or SN1 processes.This new activation of the Si-Cl bond, probably trough a Si-Cl...BiCl3 interaction gives a hard-soft reagent that can generate a silicenium cation, was also observed with Me3SiBr, BiBr3 and Me3SiI, BiI3 systems.The reaction is also presented as a possible alcoholysis of chlorosilanes, which can lead to siloxanes in non-aqueous conditions. catalysis / halogenation / alcohol / ester / silyl ether / chlorosilane / chlorotrimethylsilane / bromotrimethylsilane / iodotrimethylsilane / siloxane / bismuth (III) halide
Labrouillere, Mireille,Roux, Christophe Le,Oussaid, Abdelouahad,Gaspard-Iloughmane, Hafida,Dubac, Jacques
p. 522 - 530
(2007/10/02)

SYNTHESIS OF SOME 2'-C-ALKYL DERIVATIVES OF 9-(2-PHOSPHONOMETHOXYETHYL)ADENINE AND RELATED COMPOUNDS
To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI.After protection of the adenine amino group by benzylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with bis(2-propyl) p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride.After deprotection, the obtained phosphonate diesters XII were converted into phosphoniuc acids I by transsilylation and hydrolysis.This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives.The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2,6-Diaminopurine derivative XXIIb was obtained analogously. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-phosphonylmethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.
Cvorakova, Hana,Holy, Antonin,Rosenberg, Ivan
p. 2069 - 2094
(2007/10/02)

Oxygenated alicyclic compounds and their use in perfumery
A compound of formula STR1 wherein R1 represents a hydrogen atom or a saturated, linear or branched, alkyl radical, having from 1 to 4 carbon atoms, and R2 designates a lower alkyl radical, saturated or unsaturated, linear or branched; or any mixture containing a predominant amount of said compound (I), together with its isomer of formula STR2 wherein R1 and R2 are defined as above. Compounds (I) and their mixtures mentioned above develop odor notes of the woody-amber type and are therefore used as perfuming ingredients for the preparation of perfuming compositions and perfumed articles. A process for the preparation of compounds (I) and their mixtures is disclosed.
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(2008/06/13)

6-phenoxymethyl-4-hydroxytetrahydropyran-2-ones and 6-thiphenoxymethyl-4-hydroxytetrahydropyran-2-ones and the corresponding dihydroxycarboxylic acid derivatives, salts and esters, and in treating hypercholesterolemia
6-Phenoxymethyl-4-hydroxytetrahydropyran-2-ones and 6-thiophenoxymethyl-4-hydroxytetrahydropyran-2-ones and the corresponding dihydroxycarboxylic acid derivatives, salts and esters, processes for the preparation of these compounds, their use as pharmaceuticals, pharmaceutical preparations and novel phenols and thiophenols Compounds of the general formula I STR1 and the corresponding open-chain dihydroxycarboxylic acids of the formula II STR2 in which X, Y and Z have the meanings given, and pharmacologically tolerated salts thereof with bases and pharmacologically tolerated esters thereof, processes for the preparation of these compounds, their use as pharmaceuticals and pharmaceutical preparations are described. Novel phenols and thiophenols of the formula III STR3 in which X, Y and Z have the meanings given, are also described.
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(2008/06/13)

Ion-Molecule Reactions of Vibrationally State-Selected NO+ with Small Alkyl Halides
The effects of vibrational excitation in NO+ (v=0-5) on its reactivity with small alkyl halides (CnH2n+1X; n=1-3; X=Cl, Br, I) have been investigated under thermal translational conditions.The method combines resonance enhanced multiphoton ionization to form state-selected NO+(v), and Fourier transform in cyclotron resonance techniques to trap, react, and detect ions.Besides vibrational quenching of NO+(v > 0), which is found to be very efficient with alkyl halides, three reaction channels are observed: charge transfer, halide transfer, and CnH2nNO+ formation.Branching ratios and rate constants have been determined for the different channels as a function of the NO+(v=0) vibrationally energy.Endoergic charge transfer is efficiently driven by vibrational excitation.Halide transfer is the major channel if it is significantly exothermic for NO+(v=0).If this is not the case, adding vibrational energy in NO+(v=0) is only marginally effective in driving this channel.The data suggest that rearrangements in NO+-alkyl halide reaction intermediates and in carbonium ions are very rapid.The CnH2nNO+ formation channel is only observed with n-propyl and isopropyl chloride where it is dominant for NO+(v=0).Increasing vibrational excitation inhibits C3H6NO+ formation.The results are discussed in terms of possible reaction mechanisms.
Wyttenbach, Thomas,Bowers, Michael T.
p. 8920 - 8929
(2007/10/02)

MECHANISM OF THE CATALYSIS OF THE ARBUZOV REACTION BY TRANSITION METAL COMPLEXES. IV. EFFECT OF THE NATURE OF THE P(III) DERIVATIVES ON THE METAL-COMPLEX CATALYSIS OF THE ARBUZOV REACTION
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Sentemov, V. V.,Krasil'nikova, E. A.,Berdnik, I. V.
p. 50 - 52
(2007/10/02)

Kinetics of the Reactions of Alkyl Radicals (CH3, C2H5, i-C3H7, and t-C4H9) with Molecular Bromine
The gase-phase kinetics of the reactions of four alkyl radicals (CH3, C2H5, i-C3H7, and t-C4H9) with molecular bromine have been studied over the temperature range 296-532 K.The reactions were isolated for quantitative study in a heatable tubular reactor coupled to a photoionization mass spectrometer.Radicals were homogeneously generated in the reactor by pulsed photolysis of suitable precursor molecules at 193 or 248 nm.The subsequent decays of the radical concentration in the presence of different Br2 concentrations were monitored in time-resolved experiments.Rate constants were obtained at five temperatures.The Arrhenius expressions (k = A exp(-E/RT)) that describe the temperature dependencies of the measured rate constants of the R + Br2 -> RBr + Br reactions are as follows 3 molecule-1 s-1), E/(kcal mol-1)>: R = CH3 ; R = C2H5 ; R = i-C3H7 ; R = t-C4H9 .The trend in the measured rate constants and the results of prior studies of the dynamics of the CH3 + Br2 reaction indicate that the reactivity of R + Br2 reactions is determined largely by long-range attractive forces and not by reaction thermochemistry.
Timonen, R. S.,Seetula, J. A.,Gutman, D.
p. 3005 - 3008
(2007/10/02)

Thermal rearrangements of allenes. Synthesis and mechanism of cycloaromatization of π and heteroatom bridged diallenes
The synthesis and thermal rearrangement of several π and heteroatom bridged diallenes has been investigated. o-Diallenylbenzenes 5, 14, 24 and bis(γ,γ-dimethylallenyl) ether 8 were prepared by addition of dibromocarbene to the corresponding divinyl precursor, followed by treatment of the resulting dibromocyclopropane derivative with methyllithium. Bis(γ,γ-dimethylallenyl) sulfide 10 was generated by reaction of (γ,γ-dimethylallenyl)lithium with sulfur dichloride, while the corresponding selenides 12 and 16 were synthesized by an SN2′ reaction of sodium selenide with α,α-dimethylpropargyl bromide. All diallenes prepared display a remarkable thermal reactivity and undergo a facile cycloaromatization. Gentle heating of diallenes 5, 14, 12, and 16 gave the naphthalene derivatives 6 and 15 and selenophene derivatives 13 and 17, respectively, in practically quantitative yields. Diallenes 8, 10, and 24 underwent spontaneous cyclization during preparation yielding furan 9, thiophene 11, and naphtho[b]cyclobutane 25, respectively. A kinetic study of the rearrangement and measurement of the kinetic isotope effect using diallenes 5, 14, 12, and 16, revealed that the cyclization is a two-step process. The first and rate-determining step is an electrocyclic reaction yielding as intermediates ω-xylylenes 20 and 21, while the second and more rapid step entails a [1,5]hydrogen transfer.
Braverman, Samuel,Duar, Ytzhak
p. 5830 - 5837
(2007/10/02)

Organochromium(III) macrocyclic complexes. Factors controlling homolytic vs heterolytic cleavage of the chromium-carbon bond
Kinetics studies were done of the homolytic and heterolytic cleavage reactions of the chromium-carbon bonds in the complexes RCr(L)An+ (where L = [15]aneN4 = 1,4,8,12-tetraazacyclopentadecane; A = H2O, OH-). Activation parameters (ΔH?/kJ mol-1, ΔS?/J mol-1 K-1) for homolysis of RCrL(H2O)2+ are as follows: 111 ± 2, 54 ± 6 (R = p-CH3C6H4CH2); 103 ± 2, 28 ± 5 (C6H5CH2); 101 ± 3, 22 ± 9 (p-BrC6H4CH2); 110 ± 3, 62 ± 6 (i-C3H7). The ΔH? and ΔS? parameters are considerably smaller than those for homolysis of (H2O)5CrR2+ analogues. Primary alkyl macrocyclic complexes do not undergo homolysis. The complexes RCrL(OH)+ slowly hydrolyze for R = n-C3H7 and i-C3H7 whereas those for which R = ArCH2 do not. The activation parameters for hydrolysis are 78 ± 1, -53 ± 2 (R = i-C3H7) and 83 ± 3, -46 ± 9 (n-C3H7). This pathway shows no solvent deuterium isotope effect. The complexes RCrL(H2O)2+ are not subject to acidolysis by H3O+ or H2O, unlike their (H2O)5CrR2+ analogues.
Shi, Shu,Espenson, James H.,Bakac, Andreja
p. 4318 - 4322
(2008/10/08)

Ionic Chlorination (Bromination) of Alkanes and Cycloalkanes with Methylene Chloride (Bromide)/Antimony Pentafluoride
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Olah, George A.,Wu, An-hsiang,Farooq, Omar
p. 1463 - 1465
(2007/10/02)

MECHANISM OF THE CATALYSIS OF THE ARBUZOV REACTION BY COMPLEX COMPOUNDS OF TRANSITION METALS. III. INFLUENCE OF THE NATURE OF THE ARYL HALIDE USED ON THE EASE OF ARBUZOV REACTION CATALYZED BY METAL COMPLEXES
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Sentemov, V. V.,Krasil'nikova, E. A.,Berdnik, I. V.
p. 2406 - 2407
(2007/10/02)

Tetranuclear halide-alkoxide clusters of molybdenum formed by the coupling of M-M triple-bonded dinuclear compounds. Synthesis, characterization, and molecular structures of Mo4F2(O-i-Pr)10, Mo4X3(O-i-Pr)9, and Mo4X4(O-i-Pr)8 (X = Cl, Br, I)
Hydrocarbon solutions of Mo2(O-i-Pr)6(M≡M) react with MeCOX or Me3SiX (GX, 1.5 equiv) to give Mo4X3(O-i-Pr)9 (I; X = Cl, Br, I) and GO-i-Pr. Complexes I may be viewed as the coupled products of Mo2X2(O-i-Pr)4 and Mo2X(O-i-Pr)5. A further reaction between I and GX (1 equiv) or the direct reaction between Mo2(O-i-Pr)6 and GX (2 equiv) carried out in toluene leads to Mo4X4(O-i-Pr)8 compounds (II). The compounds II are unstable in solution at elevated temperatures (>60°C) and react further to give Mo4O2X2(O-i-Pr)6 compounds (III) with elimination of i-PrX (2 equiv). The ease of the conversion of II to III follows the order X = I > Br > Cl and occurs more readily in CH2Cl2 than in hydrocarbon solvents. Attempts to prepare fluoro analogues of II and III by related reaction procedures have failed to give an isolable single product, as did the addition of i-PrOH (>8 equiv) to the known compound Mo4F4(O-t-Bu)8. The reaction between Mo2(O-i-Pr)6(M≡Af) and 1 equiv of either MeCOF or PF3 in toluene at -78°C yielded the thermally unstable, red, crystalline compound Mo4F2(O-i-Pr)10 (IV). Compounds I have been characterized by a variety of spectroscopic techniques and, for X = Br, by a single-crystal X-ray study. Collectively the data present a uniform structural picture involving butterfly Mo4 units [five Mo-Mo distances of 2.50 A? (averaged) and one long Mo-Mo distance of 3.29 A?] supported by alkoxide bridges, of which two cap the external triangular faces of the butterfly and four edge-bridge backbone and wingtip molybdenum atoms. The wingtip molybdenum atoms have two terminal ligands (X and O-i-Pr) while the backbone molybdenum atoms have only one terminal ligand (X or O-i-Pr). The local geometry about each molybdenum atom is square pyramidal, MO4X, where X (Cl or O-i-Pr) occupies the apical site. The compounds II show low-temperature limiting 1H NMR spectra indicative of a butterfly C21, Mo4 structure related to I by the substitution of the apical O-i-Pr ligand on the backbone molybdenum atom by X. The 1H NMR spectra for II recorded at room temperature indicate O-i-Pr ligand scrambling on the NMR time scale. X-ray studies for X = Br confirmed the anticipated butterfly Mo4 geometry [five Mo-Mo distances of 2.50 A? (averaged) and one Mo-to-Mo distance of 3.2 A?] but, for X = Cl, revealed a square Mo4 unit (Mo-Mo = 2.38 A?) supported by eight μ-O-i-Pr ligands, four above and four below the M4 plane. The Mo-Cl bonds are terminal and radiate from the center of the square. The square and butterfly Mo4 units can be viewed as arachno fragments of the well-known closo-Mo6(μ3-X)84+ moiety. The arachno Mo4 subunits all have abnormally long radial Mo-L bonds. This phenomenon arises from what is termed the radial cluster influence. The compounds III are formulated as derivatives of II in which the two μ3-O-i-Pr ligands are replaced by capping (μ3) oxo ligands and the backbone molybdenum atoms lack terminal Mo-X bonds. Compound IV contains a rectangular Mo4 unit having two short, 2.23 A?, and two long, 3.41 A?, distances corresponding to M≡M and nonbonding M-to-M distances, respectively. The M≡M bonds are unbridged, and the tetranuclear compound is viewed as a dimer, [Mo2(μ-F)(μ-O-i-Pr)(O-i-Pr)4]2. In solution the molecules undergo facile disproportionation to give Mo2(O-i-Pr)6 and other products presumably derived from the reactive species Mo2F2(O-i-Pr)4. The latter has been trapped, by the addition of PMe3 (2 equiv) to hydrocarbon solutions of IV, as the adduct Mo2F2(O-i-Pr)4(PMe3)2, for which spectroscopic data indicate a structural analogy to the previously characterized compound Mo2F2(O-t-Bu)4(PMe3) 2(M≡M). Collectively these studies provide the first examples of the coupling of M-M triple bonds to give 12-electron M4 clusters. These results are compared to the previously reported condensation of Mo-Mo quadruple bonds. Crystal data: (i) for Mo4Br3(O-i-Pr)9 at -164°C, a = 18.645 (7) A?, b = 11.825 (3) A?, c = 19.046 (7) A?, β = 94.64 (2)°, Z = 4, dcalcd = 1.833 g cm-3, and space group P21/c; (ii) for Mo4Br4(O-i-Pr)8 at -160°C1 a = 20.042 (5) A?, b = 10.980 (2) A?, c = 18.602 (4) A?, β = 112.60 (1)°, Z = 4, dcalcd = 2.067 g cm-3, and space group A2/a; (iii) for Mo4Cl4(O-i-Pr)8 at -162°C, a = 9.971 (10) A?, b = 9.971 (10) A?, c = 18.272 (19) A?, Z = 2, dcalcd = 1.825 g cm-3, and space group I4/m; (iv) for Mo4F2(O-i-Pr)10 at -160°C, a = 13.143 (2) A?, b = 10.339 (2) A?, c = 9.088 (1) A?, α = 108.87 (1)°, β = 77.16 (1)°, γ = 113.03 (1)°, Z = 1, and space group P1.
Chisholm, Malcolm H.,Clark, David L.,Errington, R. John,Folting, Kirsten,Huffman, John C.
p. 2071 - 2084
(2008/10/08)

Oxidative addition reactions of compounds of the type (η5-C5Me5)Os(CO)LR (L = CO, PMe2Ph; R = alkyl). The role of oxidized intermediates in electrophilic cleavage reactions of osmium-carbon σ-bonds
Compounds of the type Cp*Os(CO)LR (Cp* = η5-C6Me5; L = CO, PMe2Ph; R = Me, Et, i-Pr, CH2Ph), most of them new, have been prepared and their reactions with the electrophiles CF3CO2H, Br2, and HgBr2 have been investigated. All of the electrophiles oxidatively add to give labile, formally osmium(IV) complexes of the type [Cp*Os(CO)(L)(R)(E)]+X-, one of which, [Cp*Os(CO)(PMe2Ph)(Me)(HgBr)]+, has been isolated as the PF6- salt. In all cases, the osmium(IV) complexes decompose in solution to give the normal products of electrophilic cleavage.
Johnston, Laura J.,Baird, Michael C.
p. 2469 - 2475
(2008/10/08)

Chemical process
Novel bis(3',5'-mono or dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketones are prepared by reacting a (3',5'-mono or dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketone with an N,N-dihydrocarbyl-2,6-mono or dihydrocarbyl-4-aminomethylphenol and an alkyl halide in the presence of an alkaline earth metal halide. The products are useful as antioxidants.
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(2008/06/13)

RHODIUM(I) CATALYZED CARBONYLATION REACTIONS OF HALIDES AND ETHERS
Benzylic bromides and methyl ioide react with ethers, carbon monoxide, potassium iodide, and the dimer of chloro(1,5-hexadiene)rhodium(I) to give esters in good yields.
Buchan, Caroline,Hamel, Nathalie,Woell, James B.,Alper, Howard
p. 5743 - 5746
(2007/10/02)

Reactions of Carbanions with Electron Acceptors
Second-order rate constants for reactions of families of 9-substituted fluorenide ions, 9-R-Fl(-), and related carbanions in Me2SO solution with the electron acceptors PhSO2CH2Br, PhSO2CH(Ph)Br, PhSO2C(Me)(Ph)Br, Me2CBr2, Me2C(NO2)X, PhS(O)CH2Cl, Me2C(SO2Ph)2, and Ph2I(+)Cl(-) have been measured.The carbanions used varied in basicity over a range of about 20pKHA units.For a given family, Broensted plots of log k vs. pKHA were linear, with slopes usually near unity.The relative order of rate constants correlated for the most part with the order of reduction potentials of the electron acceptors.The carbanions were converted by the electron acceptors to dimers, i.e., 9-R-Fl- -> (9-R-Fl)2, by way of a single electron transfer (e-T) mechanism.The Broensted lines for the e-T reactions of the GC6H4C(Me)CN- ion family (G = p-Cl, H, and p-Me) and the 9-t-BuFl- ion family were displaced below that of the 9-MeFl- ion family (slower rates); the kinetic points for PhC(Me)SO2Ph- and Ph2CSO2Ph- ions fell near the 9-t-BuFl- ion family line.It is demonstrated that carbanions too weakly basic to undergo thermal e-T with a given electron acceptor can be made to undergo comparable e-T reactions under photostimulation.
Bordwell, Frederick G.,Clemens, Anthony H.,Smith, Donald E.,Begemann, John
p. 1151 - 1156
(2007/10/02)

Chemical process for preparing 1,3-diketones
Novel (3',5'-dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketones are prepared by reacting an N,N-dihydrocarbyl-2,6-dihydrocarbyl-4-aminomethylphenol with a 1,3-diketone and an alkyl halide in the presence of an alkali or an alkaline earth metal hydride. The products are useful as antioxidants.
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(2008/06/13)

Hydroxyvitamin D2 compounds and process for preparing same
This invention relates to hydroxylated derivatives of vitamin D2, to processes for preparing such compounds, to intermediates utilized in such processes and to certain isotopically labelled vitamin D2 compounds. The vitamin D2 derivatives would find application in the treatment of or prophylaxsis for various disease states characterized by calcium and phosphorous imbalances and as a substitute for vitamin D3 and its metabolites in their various applications.
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(2008/06/13)

Chemical process
Novel 2,4-dihydrocarbylspiro[5.5]undeca-1,4,8-trien-3-one compounds are prepared by reacting an N,N-dihydrocarbyl,2,6-dihydrocarbyl-4-aminomethylphenol with a conjugated diene and an alkyl halide in a liquid solvent medium.
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(2008/06/13)

Antibiotics and derivatives thereof having β-lactamase inhibitory activity and production thereof
A novel antibiotic substance of the formula STR1 wherein R1 is CH3 and R2 is --CH2 --CH2 -- or R1 is H and R2 is --CH=CH--; and R3 represents hydrogen, lower alkyl or triphenylmethyl, and including the salts of the compound of formula (I) wherein R3 is hydrogen, said antibiotic substance having strong antibiotic activity and β-lactamase inhibiting effect, and a method for producing the same by aerobic cultivation of Streptomyces A271.
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(2008/06/13)

ORGANOBORON COMPOUNDS. CDV. BROMINATION OF 2-ISOPROPYL-2-BORAADAMANTANE
Bromination of 2-isopropyl-2-boraadamantane in CH2Cl2 proceeds simultaneously by both radical and electrophilic mechanisms.The first involves elimination of HBr and formation of 2-(2-bromo-2-propyl)-2-boraadamantane; this rearranges, under the action of nucleophilic reagents, to a derivative of 4-borahomoadamantane, which converts, on oxidation, to 3α-hydroxy-7α-(2-hydroxy-2-propyl)bicyclononane.The second direction includes cleavage of a B-C(isopropyl) bond with formation of i-PrBr and 2-bromo-2-boraadamantane, oxidation of which leads to 3α, 7α-dihydroxybicyclononane.In the presence of H2O, a solvated Br+ also takes part in the bromination, which results in formation of hydroxy (3-noradamantyl)isopropylborane, which is oxidized to 3-noradamantanol.Depending on the reaction conditions one of the three possible directions may predominate.
Mikhailov, B. M.,Shchegoleva, T. A.,Shashikova E. M.,Kiselev, V. G.
p. 23 - 32
(2007/10/02)

Relative Bond Dissociation Energies for Two-Ligand Complexes of Cu+ with Organic Molecules in the Gas Phase
Ralative two-ligand dissociation enthalpies, δD(Cu+-2L), for Cu+ with 43 organic molecules are determined.A pulsed-laser volatilization/ionization sourse is used to generate Cu+ which reacts with EtCl and/or other molecules to give Cu(ligand)2+ species.Equilibrium constants are measured for the ligand-exchange reactions which occur when pairs of ligand molecules are present.Free energies for two-ligand exchange are obtained from the equilibrium constant for the reaction Cu(A)2+ + 2B ->/+ + 2A.The free-energiy differences are added to give a scale of relative free energies for ligand exchange.These are converted to enthalpies to give δD(Cu+-2L) scale with the assumption that enthropy changes are small and can be neglected except for symmetry corrections which are made in appropriate cases.Dependence of δD(Cu+-2L) on functional group and substituent effects is analyzed.These results for Cu+ are compared to available results for other reference acids: H+, Al+, Mn+, Li+, and CpNi+.These comparisons show that Cu+ is a softer acid than the other reference acids.This is apparent from the relative preference of Cu+ for mercaptans and HCN compared to alcohols and other oxygen bases.
Jones, Roger W.,Staley, Ralph H.
p. 2296 - 2300
(2007/10/02)

Crossover Products from Joint Reactions of Alkenes, Alkynes, and Hydrogen Halides
Joint reactions of alkenes, alkynes, and hydrogen bromide or hydrogen chloride were examined.Ethylene was the only olefin which afforded a crossed cycloadduct, viz. 1-bromo-1-methylcyclobutane (3), in its reaction with propyne and HBr.Reactions of propene with propyne/HBr, with 1-butyne/HCl, and with 2-butyne/HCl as well as reactions of 1-butene with propyne/HBr gave only cyclic and/or acyclic crossover products, which are derived from alkylation of the alkyne by the alkene.Dihalotrialkylcyclobutanes were obtained as cyclic crossover products, which had carbon skeletons composed of two molecules of the acetylene and of one molecule of the olefin used.
Griesbaum, Karl,Mach, Helmut
p. 3818 - 3829
(2007/10/02)

Thallium(I) Carboxylate Modification of the Hunsdiecker Reaction
Treatment of a thallium(I) carboxylate with 1 molar equivalent of bromine gives the corresponding thallium(III) carboxylate dibromide.High yields of primary alkyl bromides are obtained if the thallium(III) carboxylate dibromide is treated with 0.5 mol equiv. of bromine in refluxing carbon tetrachloride.Pyrolysis of the thallium(III) derivative in the absence of added bromine gives a low yield of the corresponding alkyl bromide.The use of thallium(I) carboxylates for the preparation of alkyl bromides in high yields is limited to the salts of primary carboxylic acids.A simple procedure for the preparation of alkyl bromides from carboxylic acids using thallium(I) carbonate has been developed.
Cambie, Richard C.,Hayward, Rodney C.,Jurlina, Jeffrey L.,Rutledge, Peter S.,Woodgate, Paul D.
p. 2608 - 2614
(2007/10/02)

Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
The equilibrium positions have been determined for the halogen redistribution reactions of tri-n-butyltin halides with a variety of structurally different types of alkyl halides and with acetyl halides.These have been related through the reaction ΔGo values to carbon-halogen bond dissociation energy differences.It is suggested that the trends observed in the latter may provide evidence for the existence of a small steric bond weakening effect in the order C-I > C-Br > C-Cl bonds on going from methyl to primary, secondary, and tertiary alkyl halides.On the other hand, with the 2,3-? bond containing allyl, benzyl, and propargyl halides , α-haloacetones, and haloacetonitriles, there may be some type of electronic carbon-halogen bond strengthening effect which lies in order C-I > C-Br > C-Cl.Finally, for the acetyl halides, the data are in agreement with increases in bond strengths resulting from ? contributions being in the order C-Cl > C-Br > C-I.
Friedrich, Edwin C.,Abma, Charles B.
p. 1367 - 1371
(2007/10/02)

Aminopyrrole derivatives
Pharmacologically-active aminopyrrole derivatives of the formula STR1 wherein: R is selected from hydrogen, (C1-4)alkyl, benzyl and chlorobenzyl; R1 is selected from hydrogen, (C1-4)alkyl, phenyl and phenyl substituted by a radical selected from methyl, ethyl, methoxy, ethoxy, benzyloxy, fluoro, chloro and bromo; R2 and R3 individually represent hydrogen or (C1-4)alkyl or, taken together, represent an isopropylidene, a benzylidene or a chlorobenzylidene radical; R4 is selected from (C2-4)alkanoyl; carbo(C1-3)alkoxy; benzoyl, benzoyl substituted by a radical selected from chloro, methoxy or ethoxy; carbamoyl, methylcarbamoyl and phenyl carbamoyl; R5 is selected from hydrogen, (C1-4)alkyl, carbo(C1-3)alkoxy, carbomethoxymethyl, carbethoxymethyl, trifluoromethyl and carbamoyl, with the proviso that when R is hydrogen, R1 and R5 are methyl and R4 is carbethoxy, R2 and R3 cannot simultaneously represent hydrogen; And a salt thereof with a pharmaceutically acceptable acid. The compounds have anti-inflammatory and CNS-depressant utility. They are also useful as analgesics and antipyretics and display a very low degree of anti-ulcerogenic activity.
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(2008/06/13)

Process for substituting and dequaternizing pyridylethyl quaternary salts of pyridine and bypyridine bases
A process for dequaternizing a 2-(2-pyridyl)ethyl or 2-(4-pyridyl)ethyl quaternary salt of a pyridine or bipyridine base comprising the step of heating or reacting the pyridylethyl quaternary salt with a caustic material such as sodium hydroxide. Also included is a process for preparing a second pyridine base (or a bipyridine base) in which a first pyridine base is initially selected and its 2-(2-pyridyl)ethyl or 2-(4-pyridyl)ethyl quaternary salt or its acid salt prepared. An electrophilic, nucleophilic or coupling reaction can then be performed on the quaternary salt to change the substituent or to form the bipyridyl coupling and the resultant salt dequaternized with a caustic material, such as sodium hydroxide, to produce a second pyridine or a bipyridine base.
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(2008/06/13)