- Carbodeoxygenation of biomass: The carbonylation of glycerol and higher polyols to monocarboxylic acids
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Glycerol is converted to a mixture of butyric and isobutyric acid by rhodium- or iridium-catalysed carbonylation using HI as the co-catalyst. The initial reaction of glycerol with HI results in several intermediates that lead to isopropyl iodide, which upon carbonylation forms butyric and isobutyric acid. At low HI concentration, the intermediate allyl iodide undergoes carbonylation to give vinyl acetic acid and crotonic acid. Higher polyols CnH n+2(OH)n are carbonylated to the corresponding C n+1 mono-carboxylic acids. Copyright
- Coskun, Timur,Conifer, Christopher M.,Stevenson, Laura C.,Britovsek, George J. P.
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Read Online
- Catalytic Halide Exchange in Hydrocarbons Promoted by Aluminas Coated with Phosphonium Salts
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Passing a mixture of two different alkyl halides, in the gas phase, through a column filled with alumina and a phosphonium salt, gives halide-exchange products which are collected at the outlet by condensation; the process is catalytic and allows transformations to be carried out in a continuous flow process.
- Angeletti, Enrico,Tundo, Pietro,Venturello, Paolo
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Read Online
- Synthesis, Structure, and Reactivity of Stable Alkyl and Aryl Iodide Complexes of the Formula 5-C5H5)Re(NO)(PPh3)(IR)>(1+)BF4(1-)
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Reaction of methyl complex (η5-C5H5)Re(NO)(PPh3)(CH3) with HBF4*Et2O (CH2Cl2, -78 deg C) and then alkyl and aryl iodides RI gives adducts 5-C5H5)Re(NO)(PPh3)(IR)>(1+)BF4(1-) (3: R = a, CH3; b, CH2CH3; c, CH2CH2CH3; d, CH2CH2CH2CH3; e, CH2Si(CH3)3; f, CH2CH2CH2Cl; g, CH2Cl; h, C6H5; i, p-C6H4OCH3; 63-87percent).The structure of 3e*(CH2Cl2)0.5 is confirmed by X-ray crystallography and compared to that of iodide complex (η5-C5H4CH3)Re(NO)(PPh3)(I) .The C-I bond is not significantly longer than those in free alkyl iodides.Complexes 3a-c decompose (48-60 h, CD2Cl2, 25 deg C) to bridging halide complexes (SS,RR)-5-C5H5)Re(NO)(PPh3)>2X(1+)BF4(1-) and react with CH3CN to give acetonitrile complex 5-C5H5)Re(NO)(PPh3)(NCCH3)>(1+)BF4(1-) (82-87percent) and RI (72-82percent).Complexes 3a-c rapidly alkylate PPh3 (5-C5H5)Re(NO)(PPh3)(I) (>99-92percent).The reaction of 3b and PPh3 is second order (ΔH(excit.) = 12.9 +/- 0.6 kcal/mol, ΔS(excit.) = -12.0 +/- 0.9 eu) and (3.3 +/- 1.3) x 1E5 faster (298 K) than that of ICH2CH3 and PPh3 to give Ph3PCH2CH3(1+)I(1-) (ΔH(excit.) = 16.3 +/- 0.4 kcal/mol, ΔS(excit.) = -25.9 +/- 1.5 eu).Complex 3b reacts similarly with Br(1-), but 3h yields IC6H5 and (η5-C5H5)Re(NO)(PPh3)(Br).Ethyl bromide and chloride complexes analogous to 3b are less stable but can be prepared in situ.
- Winter, Charles H.,Veal, William R.,Garner, Charles M.,Arif, Atta M.,Gladysz, J. A.
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Read Online
- Visible-light-mediated multicomponent reaction for secondary amine synthesis
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The widespread presence of secondary amines in agrochemicals, pharmaceuticals, natural products, and small-molecule biological probes has inspired efforts to streamline the synthesis of molecules with this functional group. Herein, we report an operationally simple, mild protocol for the synthesis of secondary amines by three-component alkylation reactions of imines (generated in situ by condensation of benzaldehydes and anilines) with unactivated alkyl iodides catalyzed by inexpensive and readily available Mn2(CO)10. This protocol, which is compatible with a wide array of sensitive functional groups and does not require a large excess of the alkylating reagent, is a versatile, flexible tool for the synthesis of secondary amines.
- Wang, Xiaochen,Zhu, Binbing,Dong, Jianyang,Tian, Hao,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
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Read Online
- Visible-Light-Promoted Remote C-H Functionalization of o-Diazoniaphenyl Alkyl Sulfones
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Visible-light irradiation of ortho-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy)32+ results in remote Csp3-H functionalization. Key mechanistic steps in these processes involve intramolecular hydrogen atom transfer from Csp3-H bonds to aryl radicals to generate alkyl/benzyl radicals. Subsequent polar crossover occurs by single-electron oxidation of the alkyl/benzyl radicals to carbenium ions that then intercept nucleophiles. We have developed remote hydroxylations, etherifications, an amidation, and C-C bond formation processes using this strategy.
- Du, Shaofu,Kimball, Elizabeth Ann,Ragains, Justin R.
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supporting information
p. 5553 - 5556
(2017/10/25)
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- Sterically controlled alkylation of arenes through iridium-catalyzed C-H borylation
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Complementary chemistry: A one-pot method for the site-selective alkylation of arenes controlled by steric effects is reported. The process occurs through Ir-catalyzed C-H borylation, followed by Pd- or Ni-catalyzed coupling with alkyl electrophiles. This selectivity complements that of the typical Friedel-Crafts alkylation; meta-selective alkylation of a broad range of arenes with various electronic properties and functional groups occurs in good yield with high site selectivity. Copyright
- Robbins, Daniel W.,Hartwig, John F.
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supporting information
p. 933 - 937
(2013/02/25)
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- Simple synthesis of fresh alkyl iodides using alcohols and hydriodic acid
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A simple synthesis of fresh alkyl iodides using alcohols and hydriodic acid (HI) is reported. The alkyl iodides were obtained in quick and easy work-up with good to excellent yields (66-94%) and very high purities (97-99%). Freshly prepared iodomethane and 1-iodobutane were applied to synthesize biologically relevant 3,7-dimethyladenine and 9-butyladenine, which were characterized thoroughly using 1D and 2D NMR, individually.
- Klein, Suzane M.,Zhang, Cungen,Jiang, Yu Lin
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p. 2638 - 2641
(2008/09/19)
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- Transformation of tertiary amines into alkylating reagents by treatment with 2-chloro-4,6-dimethoxy-1,3,5-triazine. A synthetic application of side-reaction accompanying coupling by means of 4-(4,6-dimethoxy-[1,3,5] triazin-2-yl)-4-methyl-morpholin-4-ium chloride (DMTMM)
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Mild reaction conditions are described for the preparation of a number of alkyl chlorides and 2-dialkyl(aryl)amino-4,6-dirnethoxy-1,3,5-triazines by dealkylation of quaternary triazinylammonium chlorides formed as reactive intermediates in reaction of tertiary amines with 2-chloro-4,6-dimethoxy-1,3,5- triazine. The high selectivity of substitution was observed within the reactivity order of the alkyl groups: benzyl ～ allyl > methyl > n-alkyl. Studies on dealkylation of S-(-)-J-dimethyl-(1-phenylethyl)amine to R-(+)-1-chloro-1-phenylethane revealed that reaction proceeded with an inversion of configuration on the carbon atom as may be expected for SN2 type substitution. The scope of reaction was extended by exchange of anion in quaternary triazinylammonium chlorides with 1-, SCN-, C6H5O-, CH3COO- followed by N-dealkylation step.
- Kolesinska,Kaminski
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experimental part
p. 2115 - 2123
(2009/04/07)
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- Photolysis of 1-alkylcycloalkanols in the presence of (diacetoxyiodo) benzene and I2. Intramolecular selectivity in the β-scission reactions of the intermediate 1-alkylcycloalkoxyl radicals
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The C-C β-scission reactions of 1-alkylcycloalkoxyl radicals, generated photochemically by visible light irradiation of CH2Cl 2 solutions containing the parent 1-alkylcycloalkanols, (diacetoxy)-iodobenzene (DIB), and I2, have been investigated through the analysis of the reaction products. The 1-alkylcycloalkoxyl radicals undergo competition between ring opening and C-alkyl bond cleavage as a function of ring size and of the nature of the alkyl substituent. With the 1-propylcycloheptoxyl, 1-propylcyclooctoxyl, and 1-phenylcyclooctoxyl radicals, formation of products deriving from an intramolecular 1,5-hydrogen atom abstraction reaction from the cycloalkane ring has also been observed. The results are discussed in terms of release of ring strain associated to ring opening, stability of the alkyl radical formed by C-alkyl cleavage, and with cycloheptoxyl and cyclooctoxyl radicals, also in terms of the possibility of achieving a favorable geometry for intramolecular hydrogen atom abstraction.
- Antunes, Carla S. Aureliano,Bietti, Massimo,Lanzalunga, Osvaldo,Salamone, Michela
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p. 5281 - 5289
(2007/10/03)
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- Quinolinecarboxamides as antiviral agents
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The present invention provides a compound of formula I which is useful as antiviral agents, in particular, as agents against viruses of the herpes family.
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- Acetylenic α-amino acid-based sulfonamide hydroxamic acid tace inhibitors
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Compounds of the formula: are useful in treating disease conditions mediated by TNF-α, such as rheumatoid arthritis, osteoarthritis, sepsis, AIDS, ulcerative colitis, multiple sclerosis, Crohn's disease and degenerative cartilage loss.
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- Phenoxathiin derivatives as inhibitors of monoamine oxidase
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PCT No. PCT/US97/23486 Sec. 371 Date Mar. 11, 1999 Sec. 102(e) Date Mar. 11, 1999 PCT Filed Aug. 19, 1997 PCT Pub. No. WO98/12190 PCT Pub. Date Mar. 26, 1998The present invention provide phenoxathiin compounds useful in the prophylaxis and treatment of mental disorders, such as depression. The present invention also provides a method for treating a mammal having depression, anxiety or other conditions responsive to inhibition of MAO-A. A method of preparing the compounds of the present invention is also provided.
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- Primary and secondary 5-(alkyloxy)thianthrenium perchlorates. Characterization with 1H NMR spectroscopy, reactions with iodide and bromide ion, and thermal decomposition in solution
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A series of 5-(alkyloxy)thianthrenium perchlorates has been made in which the alkyl group is primary (1a-1p) and secondary (2a-2g). Preparations were carded out by reaction of the corresponding alkanol with thianthrene cation radical perchlorate in CH2Cl2 solution followed by precipitation of the perchlorate salt with dry ether. 1H NMR spectroscopy reveals that the presence of a stereogenic center in the alkyl group causes inequivalence in the ordinarily paired protons (e.g., H-4, H-6) of the thianthrenium ring. Reaction of iodide and bromide ion with primary alkyl-group compounds (e.g., methyl, ethyl, propyl, butyl) gave the alkyl halide in very good yield and by a second-order kinetic displacement. The second product was thianthrene 5- oxide (ThO). Rate constants for some of these reactions are reported. Reaction of secondary alkyl group compounds (e.g., 2-propyl, 2-pentyl, 2- hexyl, and 3-hexyl) with iodide ion gave good yields of alkyl iodide but also increasing evidence for a side reaction at the sulfonium sulfur, leading to I2, thianthrene, and secondary alkanol. Decomposition of some compounds at 100°C in solution (acetonitrile or 1,2-dichloroethane) was studied and gave alkene(s) and ThO.
- Zhao, Wenyi,Shine, Henry J.
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p. 695 - 702
(2007/10/03)
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- FORMATION OF ACYL BROMIDES FROM CARBOXYLIC ACIDS AND N-BROMOSUCCINIMIDE; SOME REACTIONS OF BROMOCYANOTRIPHENYLPHOSPHORANE
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Acyl halides, i.e., acyl bromides and acyl chlorides can be generated in high yields under mild conditions from the corresponding carboxylic acid in the presence of equivalent amounts of NBS/NCS and triphenylphosphine.The reaction between carboxylic acids, bromocyane and triphenylphosphine (Ph3PBrCN), affords under similar conditions acyl bromides.Bromocyanotriphenylphosphorane reacts also smoothly with epoxides, e.g., phenyloxirane. it appears, however, that the expected bromocyanides are not obtainable by this reaction, vicinal dibromides being formed instead.Key words: Acyl bromides, synthesis of from carboxylic acids and NBS, bromocyanotriphenylphosphorane, synthesis of alkylhalides.
- Froeyen, Paul
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p. 253 - 260
(2007/10/02)
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- 8 beta-substituted ergolines, process for their production and their use
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Compounds of formula I STR1 in which R2 means optionally substituted C1-7 alkyl, C2-7 alkenyl, CH2 --O--C1-4 alkyl or CH2 --S--C1-4 alkyl R6 means C2-6 alkyl, C3-6 alkenyl or C3-5 -cycloalkyl-C1-2 alkyl and R8 means CH2 --X, STR2 in which X stands for CN, OCH3, SCH3 or CONH2 and R1 stands for hydrogen, halogen, methyl or methoxy, and R3 and R4 each mean C1-4 alkyl or (CH2)n --N(CH3)2, in which n=1-4, and their acid addition salts, the process for their production, their use as pharmaceutical agents as well as intermediate compounds are described.
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- Ion-Molecule Reactions of Vibrationally State-Selected NO+ with Small Alkyl Halides
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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.
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p. 8920 - 8929
(2007/10/02)
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- Preparation of 6-0-alkylelsamicin A derivatives
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This invention relates to novel elsamicin A derivatives having 6-O-alkyl substitutent, a process for producing said elsamicin A derivatives, antitumor compositions containing the same as the active ingredient, and a method for therapy using said compositions.
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- Cyclic azaaliphatic compounds with a nitroxy function, processes for the preparation thereof and pharmaceutical compositions containing them
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The present invention provides anti-angina pharmaceutical compositions containing at least one compound of the formula: STR1 wherein n is 1 or 2, R is a hydrogen atom or an H-(C1 -C8)-alkylene, hydroxy-(C1 -C8)-alkylene, R1 R2 N-(C1 -C8)-alkylene, R1 R2 N-(C1 -C8)-alkylene-CO--, R1 R2 N-CO-NR3 -(C1 -C8)-alkylene or R1 R2 N-CO-- radical, A is a valency bond or an --NR4 --CO-- or --CO--NR4 -- radical, R4 is a hydrogen atom or a straight-chained or branched, saturated or unsaturated of cyclic alkyl radical containing up to 6 carbon atoms and B is a valency bond or a straight-chained or branched alkylene chain containing up to 8 carbon atoms, in which a --CH2 -- group can be replaced by a cycloalkylene radical containing 3 to 7 carbon atoms.
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- Attempted synthesis of 1,3,5-triphenyl-2,4,9-trithia-1,3,5-triplumbaadamantane. Decomposition of organolead iodides
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MNDO calculations suggest that the strength of the bridgehead carbon-hydrogen bond in 2,4,9-trithia-1,3,5-triplumbaadamantane (2a) should be only 54 kcal/mol and the hydride affinity of the corresponding bridgehead cation 2a+ should be only 215 kcal/mol. As a donor of hydrogen atoms or hydride, plumbaadamantane 2a should therefore be even more reactive than the analogous stannaadamantane 1a. Unfortunately, substituted derivative 2b could not be prepared from (Ph3PbCH2)3CH by controlled iodinolysis followed by treatment of the intermediate hexaiodide (PhI2PbCH2)3CH with Ph3SnSSnPh3. This failure results in part from the tendency of organolead diiodides R2PbI2 to undergo redistribution reactions that produce unstable triiodides RPbI3. Diiodides capable of intramolecular redistributions are particularly reactive. The resulting triiodides then decompose by a formal reductive elimination of RI and PbI2. Since the iodinolysis of (cyclopropylmethyl)triphenylplumbane (11) yields mainly (iodomethyl)cyclopropane instead of ring-opened products derived from cyclopropylmethyl cations or radicals, we suggest that the reductive elimination of RI and PbI2 from RPbI3 is concerted.
- Kobayashi, Michio,Latour, Stéphan,Wuest, James D.
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p. 2908 - 2913
(2008/10/08)
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- RAPID SYNTHESIS OF α,β UNSATURATED IODIDES: IODINATION UNDER VACUUM WITH SOLID DIPHOSPHORUS TETRAIODIDE
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α,β unsaturated alcohols are transformed in 2-5 mn and in 70-90percent yield (> 90percent pure) into their corresponding iodides when they are allowed to react with solid P2I4 under 10-2 Torr at 85 deg C.With unsymmetrical alcohols, an allylic rearrangement always leads to the more stable iodide.
- Lasne, Marie- Claire,Cairon, Philippe,Villemin, D.
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- Iodinolysis of the Co-C bond in trans-bis(dimethylglyoximato)alkyl(4-cyanopyridine)-cobalt(III) complexes: Evidence for a bimolecular oxidative mechanism
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The iodinolysis of 4CNpyCo(DH)2R (4CNpy = 4-cyanopyridine; R = CH3, CH2CH3, CH2CH2CH3, CH-(CH3)2, CH2C6H5, CH2CF3) in benzene solution is first-order with respect to both the concentration of organocobalt-(III) complex and iodine. The appearance of a transient EPR signal due to an organocobalt(IV) intermediate and the strong correlation of the logarithm of the pseudo-first-order rate constants for iodinolysis with reversible oxidation potentials along with other pertinent observations strongly suggest that the rate-limiting step of the reaction is oxidation of the six-coordinate organocobalt-(III) complex by iodine.
- Toscano, Paul J.,Barren, Elizabeth,Seligson, Allen L.
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p. 2085 - 2088
(2008/10/08)
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- Process for preparation of carboxylic acid ester containing fluorine
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Process for the preparation of carboxylic acid ester containing fluorine comprises the reaction of the reaction mixture obtained by the reaction of an organic halogen compound containing fluorine expressed by a general formula, , X - Rf- X′, , (in which, X and X′ independently stand for halogen atoms and Rfis an optionally fluorinated hydrocarbon) with carbon dioxide in the presence of zinc, with a halogenated hydrocarbon expressed by a general formula,, RY, , (in which R is an optionally fluorinated hydrocarbon and Y is a chlorine, bromine or iodine atom).
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- Radical Cations from Alkyl Iodides in Aqueous Solution
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Radical cations RI(1+) and (RIIR)(1+) are generated upon OH radical-induced oxidation of alkyl iodides in acidic (pHOH-adduct.Although alkyl iodide radical cations have been reported to exist in a solid, low-temperature matrix, they have so far not been detected in the liquid, particularly the aqueous phase.Both radical cations establish an equilibrium: .For R=Me the stability constant of the 2?-1?* three-electron-bonded species has been estimated to K>/=5E4 mol-1dm3. (RIIR)(1+) exhibits a strong optical absorption band in the visible; λmax is red-shifted with increasing electron-releasing power of R and ranges from 4115 nm (R=Me) to 470 nm (R=s-C4H9).The molecular radical cation absorbs in a comparatively much narrower range from 310-320 nm.It is suggested that it exists as (RIOH2)(1+), i.e. as an associate with one water molecule.The alkyl iodide radical cations are strong oxidants. (MeIIMe)(1+), for example, oxidizes I(1-) and Me2S with rate constant values of 7.7E9 mol-1dm3s-1 and 3.6E9 mol-1dm3s-1, respectively.
- Mohan, Hari,Asmus, Klaus-Dieter
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p. 1795 - 1800
(2007/10/02)
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- Benzofuran derivatives useful in treating diabetic complications
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A benzofuran derivative having the general formula (I): STR1 wherein R1 is hydrogen atom, a benzyl group, unsubstituted or substituted with a halogen atom or an alkyloxy group, or an alkyl group having 1 to 3 carbon atoms, R2 is hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R3 is acetyl group, ethyl group, carboxyl group or 4-methyl-2,5-dioxoimidazolidine-4-yl group, R4 is hydrogen atom, hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, carboxymethoxy group, nitro group, acetoamino group, a benzylozy group unsubstituted or substituted with a halogen atom, nitro group or an alkyloxy group or a group having the formula: --OR6, wherein R6 is an alkenyl group having 2 to 4 carbon atoms or an alkyl group having 2 to 3 carbon atoms having a halogen atom, cyano group or oxo group, R5 is hydrogen atom or methylenedioxy group together with R4 group, n is 1 or 2, and the unsubstituted or substituted N-carboxymethylsulfamoyl group, R4 and R5 are attached at 3-position, 4-position, 5-position, 6-position or 7-position of the benzofuran ring, or a nontoxic salt thereof, process for preparing the same and a pharmaceutical composition containing the same. The compounds of the present invention have powerful aldose reductase inhibiting activity, platelet aggregation inhibiting activity and arachidonic acid metabolism inhibiting activity and are useful for a remedy for treatment of diabetic complications.
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- Hydroxyvitamin D2 compounds and process for preparing same
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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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- Indirect Electrochemical Reduction of Unsaturated Alcohols
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Allyl alcohlol and some of its derivatives have been reduced electrochemically by a mercury electrode to unsaturated hydrocarbons in a strongly acidic medium containing iodide.During the reaction a shift of the double bond generally occurs.The reaction involves a transformation of the alcohol to an iodide, reaction of the iodide with mercury, protonation of the organomercury compound, and reduction of the mercuric salt to mercury.Benzyl alcohols are similarly reduced to hydrocarbons.
- Lund, Torben,Lund, Henning
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p. 387 - 390
(2007/10/02)
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- Pyrazino[2',3'-3,4]pyrido[1,2-a]indole derivatives
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Herein is disclosed pyrazino[2',3'-3,4]pyrido[1,2-a]indole derivatives, therapeutically acceptable acid addition salts thereof, processes for their preparation, methods of using the derivatives and pharmaceutical compositions. The derivatives are useful for treating hypertension in a mammal.
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- Antibiotics and derivatives thereof having β-lactamase inhibitory activity and production thereof
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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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- Catalytic Interconversion of Alkyl Halides by Gas-liquid Phase-transfer Catalysis
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High halogen exchange conversions are achieved when a gaseous mixture of alkyl halides (chlorides, bromides, iodides) is passed over a solid bed consisting of porous inorganic supports bearing a phase-transfer catalyst under gas-liquid phase-transfer catalysis (g.l.-p.t.c.) conditions.The process is catalytic since the bed undergoes no changes once it reaches operating conditions.For example, a methylene dichloride and bromoethane mixture is converted into all the halogen-exchange products, and their statistical distribution at equilibrium depends on the original ratio of the halogens in the organic reagents.Catalytic activity is high: 200 ml of such a mixture can be converted in 1 h by passage through 200 g of alumina coated with 10 percent tetrabutylphosphonium bromide.The catalytic process is promoted by the halide anions present as Q(1+)X(1-) in the liquid phase constituted by the molten catalyst and as Na(1+)X(1-) in the solid inorganic support; the halide anions partition themselves between the liquid and solid phases as a function of their respective affinities.This catalysis depends on the diffusion, partition, and adsorption of the alkyl halides between the gaseous, liquid, and solid phases, as well as on their intrinsic nucleophilic reactivity.Mechanistic aspects and industrial applicability are discussed.
- Tundo, Pietro,Venturello, Paolo,Angeletti, Enrico
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p. 485 - 492
(2007/10/02)
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- Metacyclophanes and Related Compounds. 4. Halogenations of 8,16-Dialkyl-anti-5,13-di-tert-butylmetacyclophan-1-enes and 2,7-Di-tert-butyl-trans-10b,10c-dihydropyrenes
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8,16-Dialkyl-anti-5,13-di-tert-butylmetacyclophan-1-enes (13) and 2,7-di-tert-butyl-trans-10b,10c-dialkyl10b,10c-dihydropyrenes (20 a-c) wereprepared from the corresponding alkylbenzenes in several steps.The bromination of 13 and 20 with bromine in a carbon tetrachloride solution afforded 2,7-di-tert-butyl-4,5,9,10-tetrabromo-trans-10b,10c-dialkyl-10b,10c-dihydropyrenes (2).Treatment of 20 with iodine in a boiling benzene solution gave the dealkylated compound, 2,7-di-tert-butylpyrene (28).Such dealkylation was also observed in the bromination of 20 with bromine in the presence of Fe powder.However, without Fe powder, the bromination of 20 did not give any products.It was also found that the chlorination of 13a and 20a with iodine chloride of chlorine afforded the further chlorinated 2,7-di-tert-butyl-2,4,5,9,10-hexachloro-trans-10b,10c-dimethyl-2,7,10b,10c-tetrahydropyrene (30).The reaction pathways of the halogenation of the titled compounds are also discussed.
- Tashiro, Masashi,Yamato, Takehiko
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p. 3701 - 3707
(2007/10/02)
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- Heats of Formation of Some Simple Alkyl Radicals
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Equilibrium constants, K, for the system Me + RI MeI + R were measured in solution by using electron paramagnetic resonance spectroscopy.Given the entropies of the components of the equilibrium and the heats of formation of the iodides, the relative heats of formation of the alkyl radicals were obtained.With δHf,300(Me) = 34.4 kcal mol-1 chosen as a standard, the following heats of formation for other alkyl radicals were obtained: Et, 28.0; n-Pr, 22.8; i-Pr, 19.2; s-Bu, 13.9; c-C5H9, 25.1; t-Bu, 9.4 kcal mol-1.These data lead to the following C-H bond dissotiation energies for simple alkanes: primary C-H, ca. 100; secondary C-H, ca. 96; tertiary C-H, ca. 94 kcal mol-1.
- Castelhano, A. L.,Griller, D.
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p. 3655 - 3659
(2007/10/02)
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- REACTIONS OF PERFLUOROALKYL IODIDES WITH PHOSPHORUS(III) ESTERS. KINETICS AND MECHANISM OF THE REACTIONS OF HEPTAFLUOROPROPYL IODIDE WITH ETHYLPHOPHONOUS ESTERS
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1.The kinetics of the fluoroalkylation of ethylphosphonous esters were studied, and it was shown that for the reaction low values of effective activation energy are characteristic. 2.In the first stage of the reactions of phosphonous esters with heptafluoropropyl iodide the formation of donor-acceptor complexes ocurs. 3.The rate-determining stage of the complex process is the stage of the formation of the intermediate compound.
- Garabadzhiu, A. V.,Ivanov, S. A.,Lavrent'ev, A. N.,Shibaev, V. I.
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p. 1905 - 1910
(2007/10/02)
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- Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
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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.
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p. 1367 - 1371
(2007/10/02)
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- Substituted N-alkoxy-N-substituted-2,6-dinitroanilines and intermediates for the preparation thereof
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A new class of 2,6-dinitroanilines substituted on the anilino nitrogen with alkoxy and alkyl groups, which compounds are active as herbicides and plant growth regulators, and intermediates useful for the preparation thereof.
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- Benzo-1,2,4-triazines
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Benzo-1,2,4-triazines-1,4-di-N-oxides substituted in the 3-position with a substituted amino group and optionally substituted in the benzo ring are antimicrobial agents. The compounds, of which 3-(N-acetoacetylamino)benzo-1,2,4-triazine-1,4-di-N-oxide is a typical embodiment, are prepared from the corresponding 2-aminobenzo-1,2,4-triazine-1,4-di-N-oxide through alkylation or acylation.
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- Anti-arthritic 1H-pyrimido-(5,4,3-kl)phenothiazine-1,3(2H)-diones and 1-thiones
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1H-Pyrimido[5,4,3-kl]phenothiazine-1,3(2H)-diones are prepared from the corresponding 1-thione-3-one compounds by methylation followed by acid hydrolysis. The 1,3-dione products and 1-thione-3-one intermediates are useful as anti-arthritic agents.
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