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Quantitative reaction kinetics in the liquid state by in situ XAFS
By quantitative evaluation of in situ recorded Br K-edge XAFS spectra we obtained Kinetic parameters for the halogen exchange in 2-bromopropane with sodium iodide ('Finkelstein reaction'). The results compare well with the classical data by Ingold and co-workers. Thus, XAFS is a suitable method to quantitatively monitor reactions in the liquid state.
Epple, Matthias,Troeger, Larc,Hilbrandt, Nicole
p. 3035 - 3037
(1997)
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McCauley,Hilsdorf
p. 5101,5102,5104
(1958)
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Photoinduced Palladium-Catalyzed Dicarbofunctionalization of Terminal Alkynes
Herein, a conceptually distinct approach was developed that allowed for the dicarbofunctionalization of alkynes at room temperature using simple, bench-stable alkyl iodides and a second molecule of alkyne as coupling partner. Specifically, the photochemical activation of palladium complexes enabled this strategic dicarbofunctionalization via addition of alkyl radicals from secondary and tertiary alkyl iodides and formation of an intermediate palladium vinyl complex that could undergo subsequent Sonogashira reaction with a second alkyne molecule. This alkylation–alkynylation sequence allowed the one-step synthesis of 1,3-enynes including heteroarenes and biologically active compounds with high efficiency without exogenous photosensitizers or oxidants and now opens up pathways towards cascade reactions via photochemical palladium catalysis.
Yang, Zhen,Koenigs, Rene M.
supporting information
p. 3694 - 3699
(2021/02/01)

Visible-light-mediated multicomponent reaction for secondary amine synthesis
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
supporting information
p. 5028 - 5031
(2021/05/28)

Visible-Light-Mediated C-I Difluoroallylation with an α-Aminoalkyl Radical as a Mediator
Herein, we report a protocol for direct visible-light-mediated C-I difluoroallylation reactions of α-trifluoromethyl arylalkenes with alkyl iodides at room temperature with an α-aminoalkyl radical as a mediator. The protocol permits efficient functionalization of various α-trifluoromethyl arylalkenes with cyclic and acyclic primary, secondary, and tertiary alkyl iodides and is scalable to the gram level. This mild protocol uses an inexpensive mediator and is suitable for late-stage functionalization of complex natural products and drugs.
Yue, Fuyang,Dong, Jianyang,Liu, Yuxiu,Wang, Qingmin
supporting information
p. 7306 - 7310
(2021/10/01)

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)

A transition-metal-free Heck-type reaction between alkenes and alkyl iodides enabled by light in water
A transition-metal-free coupling protocol between various alkenes and non-activated alkyl iodides has been developed by using photoenergy in water for the first time. Under UV irradiation and basic aqueous conditions, various alkenes efficiently couple with a wide range of non-activated alkyl iodides. A tentative mechanism, which involves an atom transfer radical addition process, for the coupling is proposed.
Liu, Wenbo,Li, Lu,Chen, Zhengwang,Li, Chao-Jun
supporting information
p. 6170 - 6174
(2015/06/08)

Sterically controlled alkylation of arenes through iridium-catalyzed C-H borylation
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.
supporting information
p. 933 - 937
(2013/02/25)

Carbodeoxygenation of biomass: The carbonylation of glycerol and higher polyols to monocarboxylic acids
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.
supporting information
p. 6840 - 6844
(2013/07/05)

Selective reduction of biomass by hydriodic acid and its in situ regeneration from iodine by metal/hydrogen
HI returns: Hydroiodic acid is a highly selective reducing reagent for a wide variety of substrates. Its application is limited by the formation of iodine and the difficulty in reconverting that iodione back to HI in situ. We report the facile conversion of I2 to HI by metal-catalyzed hydrogenation in the presence of water, and demonstrate the utility of this process in the conversion of fructose to 5-methyfurfural and glycerol to 2-iodopropane. Copyright
Yang, Weiran,Grochowski, Matthew R.,Sen, Ayusman
scheme or table
p. 1218 - 1222
(2012/09/08)

C-F bond activation with an apparently benign ethynyl dithiocarbamate, and subsequent fluoride transfer reactions
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Ung, Gael,Bertrand, Guy
supporting information
p. 12955 - 12957,3
(2020/09/16)

Nickel-catalyzed Negishi cross-couplings of secondary nucleophiles with secondary propargylic electrophiles at room temperature
(Chemical Equation Presented) Mild thing: The first nickel-based catalysts for cross-couplings of secondary organometallic nucleophiles with secondary alkyl electrophiles have been developed. Thus, Negishi reactions proceed under mild conditions (at room temperature with no basic activators) in the presence of NiCl2·glyme and a tridentate ligand (see scheme).
Smith, Sean W.,Fu, Gregory C.
supporting information; experimental part
p. 9334 - 9336
(2009/05/16)

Mechanism of decomposition of quasiphosphonium intermediates: Borderline SN1 character of alkyl-oxygen fission in sec-alkyloxyphosphonium salts
Short-lived alkoxyphosphonium intermediates have been detected in the interactions of alkyl diphenylphosphinites ROPPh2 (R = Et, Pr i, Bu8, and 3-pentyl) with iodomethane at room temperature. Phosphorus chemical shifts for the sec-alkoxy(methyl) diphenylphosphonium iodides (δp 68.6-68.7 ppm) are at slightly higher field than for ethoxy(methyl)diphenylphosphonium iodide (δp 72.4 ppm), in accord with higher electron density at phosphorus in the secondary alkyl sytems. Relative rates of decomposition in CDCl3 (Me > Et > Pri ? neopentyl) are in accord with SN2-type cleavage of the R-O bond but within the secondary alkyl series the relative rates (Pri 8 N1 mechanism is proposed.
Hudson,Qureshi
p. 473 - 480
(2007/10/03)

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
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
p. 5281 - 5289
(2007/10/03)

Industrial process for the production of diphenyl sulfone compounds
A process for producing 4-isopropoxy-4′-hydroxydiphenyl sulfone useful as the developer for leuco dyes to be used in thermosensible papers, which is excellent in productivity, economical efficiency and safety and permits the production of the compounds from constantly available raw materials. This process is improved in productivity and economical efficiency as compared with those of the prior art both by shortening the production time by the use of an isopropyl iodide, which is more reactive than isopropyl bromide which have been used in the prior art.
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(2008/06/13)

Radical Yields in the Radiolysis of Branched Hydrocarbons: Tertiary C-H Bond Rupture in 2,3-Dimethylbutane, 2,4-Dimethylpentane, and 3-Ethylpentane
Gel permeation chromatography has been applied to iodine scavenging studies of the distribution of radicals produced in the radiolysis of symmetrically branched hydrocarbons 2,3-dimethylbutane, 2,4-dimethylpentane, and 3-ethylpentane. The principal iodides observed are those expected as a result of simple bond rupture. In the case of 2,3-dimethylbutane all five expected iodides are readily resolvable and it is shown that the loss of H from a tertiary position is favored over loss from a primary position by a factor of ～10. A similar ratio is also observed for 2,4-dimethylpentane. The higher ratio of 15 observed for 3-ethylpentane indicates a dependence on the number of tertiary sites on the alkane. The relative yield of ～3.3 for the loss of secondary and primary H atoms from 2,4-dimethylpentane and 3-ethylpentane is similar to that for normal alkanes, indicating a negligible effect of the adjacent tertiary carbon. In all three cases the rupture of terminal C-C bonds is relatively infrequent with C-C rupture occurring preferentially at the bonds adjacent to the tertiary carbon.
Schuler, Robert H.,Wojnarovits, Laszlo
p. 9240 - 9247
(2007/10/03)

Industrial process for the production of diphenyl sulfone compounds
A process for producing compounds of general formula (II) useful as the developer for leuco dyes to be used in thermosensible papers, which is excellent in productivity, economical efficiency and safety and permits the production of the compounds from constantly available raw materials. This process is improved in productivity, economical efficiency and safety as compared with those of the prior art both by shortening the production time by the use of, e.g., an alkyl iodide, RI, which is more reactive than alkyl bromides which have been used in the prior art, and by attaining the complete recovery and reuse of iodine by incorporating into the process the iodine recovery step of recovering iodine from the manufacturing wastewater and reacting this iodine with an alcohol to thereby self-produce an alkyl iodide.
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(2008/06/13)

Acyl iodides in organic synthesis: I. Reactions with alcohols
Reaction of acyl iodides RC(O)I (R = Me, Ph) with alcohols R′OH (R′ = Me, Et, i-Pr, t-Bu, CH2= CHCH2, HC≡CCH2) provides in the corresponding organyl iodides R′I. Unlike that 2-chloroethanol and phenol (R′ = CH 2CH2Cl, Ph) react with RC(O)I in the same way as with acyl chlorides yielding esters RCO2R′. This reaction path occurs partially also with methanol and ethanol.
Voronkov,Trukhina,Vlasova
p. 1576 - 1578
(2007/10/03)

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)

First examples of superelectrophile initiated iodination of alkanes and cycloalkanes
Direct iodination of alkanes and cycloalkanes in the presence of superelectrophiles has been accomplished for the first time. The reactions of saturated hydrocarbons with I2 in the presence of CCl4·2AlI3 at -20°C afforded monoiodides in good yields and selectivities.
Akhrem, Irena,Orlinkov, Alexander,Vitt, Sergei,Chistyakov, Anatolii
p. 1333 - 1335
(2007/10/03)

Synthesis of new quaternary phosphonium salts
A number of hitherto unknown phosphonium salts were synthesized by reaction of diisopropyliodophosphine with organic halides. A new procedure was proposed for preparation of alkyl iodides.
Kabachnik,Khomutova,Beletskaya
p. 26 - 27
(2007/10/03)

Primary and secondary 5-(alkyloxy)thianthrenium perchlorates. Characterization with 1H NMR spectroscopy, reactions with iodide and bromide ion, and thermal decomposition in solution
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.
p. 695 - 702
(2007/10/03)

The Kinetics and Mechanism of the Reaction of Pyridine-N-Oxides with Alkyl Halides
The kinetics of formation of N-alkoxypyridinium salts and their decomposition to the starting reagents in acetonitrile at 25°C is studied. The decomposition of the salts takes place only in the ion pair. Similar mechanism of proton and methyl group transfer in reactions with participation of pyridines and pyridine-N-oxides was demonstrated noted.
Matveev,Koblik,Popov,Savelova,Matvienko
p. 271 - 275
(2007/10/03)

13C NMR study on magnesium carbenoids
13C NMR chemical shifts suggest that α-iodoalkylmagnesium compounds have a carbenoid character in between that of α-haloalkyllithium and the corresponding zinc compounds.
Schulze, Volker,Loewe, Ralf,Fau, Stefan,Hoffmann, Reinhard W.
p. 463 - 466
(2007/10/03)

Indole derivatives as 5-HT1-like agonists
Compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R1 is a substituted alkylene; C3 -C7 cycloalkyl optionally substituted with HO; C3 -C6 alkenyl optionally substituted with aryl; C5 -C7 cycloalkenyl; or C3 -C6 alkynyl; R2 is H; halo; F3 C; NC; R8 R9 NOC; a substituted alkylene; R8 R9 NO2 S; R10 S(O)m ; R12 CON(R11); R10 SO2 N(R11); R8 R9 NOCN(R11); R10 O2 CN(R11); R13 (CH2)n CH=CH; or R7 O are selective 5-HT1 -like receptor agonists useful in the treatment of migraine, cluster headache, chronic paroxysmal hemicrania and headache associated with vascular disorders.
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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)

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)

Preparation of 6-0-alkylelsamicin A derivatives
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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(2008/06/13)

Solid-phase synthesis of RNA via a silyl-protecting-group strategy
Ribonucleoside phosphoramidites have been prepared of which the exocyclic amino functions and 2'-hydroxyl functions are protected with 2-benzoyl groups, respectively.The N-SiOMB/O-TBDMS-blocked nucleosides proved to be suitable building units in a solid-phase synthesis of the RNA-fragment 5'-AGAGUACCU-3' via a phosphite triester approach.
Dreef-Tromp, C. M.,Dam, E. M. A. van,Elst, H. van den,Boogaart, J. E. van den,Marel, G. A. van der,Boom, J. H. van
p. 378 - 383
(2007/10/02)

Iodine Atoms and Iodomethane Radical Cations: Their Formation in the Pulse Radiolysis of Iodomethane in Organic Solvents, Their Complexes, and Their Reactivity with Organic Reductants
Pulse radiolysis of iodomethane in various organic solvents leads to formation of iodine atoms or iodomethane radical cations, which in turn form complexes with iodomethane or with the solvent.Radiolysis in cyclohexane gives CH3I*I, which exhibits an absorption peak at 390 nm, whereas radiolysis in benzene forms the solvent complex, C6H6*I, which exhibits an intense broad absorption centered at 490 nm.Radiolysis of iodomethane in acetone, benzonitrile, and halogenated hydrocarbons results in formation of the radical cation CH3I.+.In the former two solvents, this species forms a complex with another molecule of iodomethane to give (CH3))2+, which absorbs at 420 nm, in agreement with previous results in aqueous solutions, but in halogenated hydrocarbons it forms complexes with the solvents, absorbing at 320-360 nm, i.e. near the absorption of monomeric CH3I.+ in water.Complexes of I atoms oxidize phenol and triphenylamine relatively slowly whereas complexes of CH3I.+ react more rapidly.The reactivity of the CH3I.+*RX complexes increases in the order of RX = CH2Cl2, CHCl3, CH2Br2, CCl4, CH3I, and for each complex the reactivity with phenol increases with increase in electron donating power of substituents.Replacing the methyl group of iodomethane radical cation with ethyl or isopropyl decreases the reactivity, whereas trifluoromethyl increases the reactivity.These oxidation reactions proceed via an intermediate complex between the iodine species and the organic reductant.
Shoute, Lian C. T.,Neta, P.
p. 4411 - 4414
(2007/10/02)

One-pot, one- and multi-carbon homologation of alkyl halides; reaction of Grignard reagents with chloroiodomethane
Reaction of a Grignard reagent (RMgX) with chloroiodomethane affords the corresponding iodide (RI) and, depending on R, solvent and temperature, iodides which are one-carbon and multicarbon homologs of RX. Allyl iodide but not allyl bromide can be monohomologated by the combined action of chloroiodomethane and isopropyl Grignard.
Hahn,Tompkins
p. 937 - 940
(2007/10/02)

Diiodosilane. 2. A Multipurpose Reagent for Hydrolysis and Reductive Iodination of Ketals, Acetals, Ketones, and Aldehydes
The reaction patterns of diiodosilane (SiH2I2, DIS) with ketals, acetals, ketones, and aldehydes were explored.The reagent may be used for mild cleavage of ketals and acetals either hydrolytically to give the parent carbonyl functionality or reductively to produce the corresponding alkyl iodide.At low temperatures (-42 deg C) and short reaction times (few minutes), catalytic amounts (5-10 molpercent) of DIS provide clean deprotection of various ketals and acetals to yield ketones and aldehydes, with no apparent reduction of the latter.At temperatures above 0 deg C, DIS effectively reduces ketals and acetals to iodoalkanes.This reduction is quite general both with respect to ketals and acetals and unprotected ketones and aldehydes.Reaction rates, however, are strikingly dependent on the substrate, with the following tendencies: (a) aromatic functionalities are generally reduced much faster than their aliphatic analogues; (b) ketals and acetals are rapidly reduced to the corresponding iodoalkanes, while free aldehydes, and particularly ketones, are essentially inert under the reaction conditions (but can be significantly activated by catalytic amounts of iodine); (c) dimethyl ketals form the parent ketones preferentially, while all other ketals, including diethyl ketals and dioxolanes, are reduced to iodoalkanes.
Keinan, E.,Perez, D.,Sahai, M.,Shvily, R.
p. 2927 - 2938
(2007/10/02)

Iodinolysis of the Co-C bond in trans-bis(dimethylglyoximato)alkyl(4-cyanopyridine)-cobalt(III) complexes: Evidence for a bimolecular oxidative mechanism
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.
p. 2085 - 2088
(2008/10/08)

New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides
New general, selective processes of homolytic alkylation of protonated heteroaromatic bases have been developed using alkyl iodides and t-BuOOH or (t-BuO)2 as sources of alkyl radicals.Both processes are based on the generation of methyl radical from the peroxides, and on iodine abstraction from the alkyl iodide by the methyl radical.The selective processes are the result of combined enthalpic and polar effects.The enthalpic factor governs the equilibrium of iodine abstraction, whereas the polar effect governs the reactivity of the alkyl radicals with the protonated heteroaromatic ring.A redox chain is operative with t-BuOOH and an unusual free-radical chain process is involved with (t-BuO)2.Both chains are particularly effective because of the electron-transfer oxidation of the pyridyl radical intermediate, the ionization potential of which (5.4-6.0 eV) is close to that of lithium (5.39 eV) or sodium (5.14 eV).
Fontana, Francesca,Minisci, Francesco,Barbosa, Maria Claudia Nogueira,Vismara, Elena
p. 995 - 999
(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)

Radical Cations from Alkyl Iodides in Aqueous Solution
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
p. 1795 - 1800
(2007/10/02)

Diiodosilane. 1. A Novel Reagent for Deoxygenation of Alcohols and Ethers
Diiodosilane (DIS), which has never been used previously in organic synthesis, has been shown to exhibit properties and reactivities that are complementary to those of iodotrimethylsilane.This new reagent was used to cleave and deoxygenate ethers and alcohols with high selectivity for secondary oxygen functions.Synthesis of DIS is easily and rapidly carried out by reacting phenylsilane with iodine.
Keinan, Ehud,Perez, Daniel
p. 4846 - 4851
(2007/10/02)

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)

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)

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)

Primary Alcohol Oxidation with N-Iodosuccinimide
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Beebe, T. R.,Adkins, R. L.,Bogardus, C. C.,Champney, B.,Hii, P. S.,et al.
p. 3126 - 3128
(2007/10/02)

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)

CATALYTIC CARBONYLATION OF PROPYLENE WITH CARBON MONOXIDE UNDER PRESSURE IN THE PRESENCE OF A PALLADIUM-ZEOLITE CATALYST
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Lapidus, A. L.,Pirozhkov, S. D.,Vellekov, A.,Garanin, V. I.,Slyunyaev, P. I.,Minachev, Kh. M.
p. 2027 - 2030
(2007/10/02)

DARSTELLUNG UND SPECTROSKOPISCHE UNTERSUCHUNGEN VON METHYL- UND ISOPROPYLANTIMONHALOGENIDEN
Halogenations of iPr3Sb yield the dihalides iPr3SbX2 X=Cl, Br, I.These compounds decompose thermally to iPrX and iPr2SbX.Halogenations of iPr2SbX produce unstable trihalides iPr2SbX3, which eliminate iPrX to give iPrSbX2.By this procedure only the bromides and iodides iPr2SbX and iPrSbX2 X=Br, I can be obtained in useful yields and purities.Pure iPrSbCl2 and iPr3Sb are products of exchange reaction of iPr2SbCl.The purity of the known methylcompounds Me2SbX X=Cl, Br, I obtained by decomposition of Me3SbX2 has been examined.MeSbI2 and Me3Sb are formed from Me2SbI.Previously unpublished ir-, 1H-nmr-, and ms-data of iPr3SbX2, R2SbX and RSbX2 R=Me, iPr, X=Cl, Br, I are discussed.
Breunig, H. J.,Kanig, W.
p. 149 - 160
(2007/10/02)

REACTIONS OF PERFLUOROALKYL IODIDES WITH PHOSPHORUS(III) ESTERS. KINETICS AND MECHANISM OF THE REACTIONS OF HEPTAFLUOROPROPYL IODIDE WITH ETHYLPHOPHONOUS ESTERS
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.
p. 1905 - 1910
(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)

Dienes useful in the preparation of 1,2,3,4,4a,5,6,7-octahydro-7-aryl-isoquinolines
Dienes of the formula SPC1 Wherein R1 and R2 are hydrogen, lower alkyl, lower alkenyl, aryl-lower alkyl, aryl-lower alkenyl, or heterocycle and Z is phenyl, substituted phenyl, naphthalene or heterocycle are disclosed. These compounds are useful as intermediates in the preparation of various pharmaceutically active 1,2,3,4,-4a,5,6,7-octahydro-7-aryl-isoquinolines.
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(2008/06/13)