- N-ALKYL THIOCARBAMOYL PHOSPHONIC ACID ESTERS-2. ALKYLATION BY METHYL IODIDE ACCOMPANIED BY PHOSPHONATE DEALKYLATION
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Thiocarbamoyl phosphonates 1 did not react with alkylating agents to give the S-alkyl derivatives 2, but gave zwitterions 3a-e in which the phosphonate ester moiety was dealkylated.In some cases starting material could be recovered.A mechanism is suggested in order to explain the relationship between the alkylation and the dealkylation steps of the reaction.
- Tashma, Zeev
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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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supporting information
p. 5028 - 5031
(2021/05/28)
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- Visible-Light-Mediated C-I Difluoroallylation with an α-Aminoalkyl Radical as a Mediator
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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
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supporting information
p. 7306 - 7310
(2021/10/01)
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- Quinim: A New Ligand Scaffold Enables Nickel-Catalyzed Enantioselective Synthesis of α-Alkylated ?-Lactam
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Herein, we report a nickel-catalyzed reductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone with broad substrate scope and high enantiomeric excess. The current art of synthesis still remains challenging on the enantioselective α-monoalkylation of pyrrolidinones. The newly designed chiral 8-quinoline imidazoline ligand (Quinim) is crucial for maintaining the reactivity and enantioselectivity to ensure the reductive cyclization of monosubstituted alkenes for unprecedented synthesis of chiral non-aromatic heterocycles.
- Chen, Yifeng,Qu, Jingping,Wu, Xianqing
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supporting information
p. 15654 - 15660
(2020/10/18)
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- SMALL MOLECULES FOR DUAL FUNCTION POSITRON EMISSION TOMOGRAPHY (PET) AND CELL SUICIDE SWITCHES
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The present invention includes an engineered cell comprising a chimeric antigen receptor (CAR) further comprising a nucleic acid molecule comprising a suicide gene comprising a ligand binding domain and a suicide domain wherein the ligand binding domain is capable of binding to radiolabeled tracer or a small molecule suicide switch. This invention also includes methods for inducing apoptosis of an engineered cell, methods for assessing the efficacy or toxicity of an adoptive cell therapy in a subject, methods for detecting the quantity of engineered T cells in a subject, methods for monitoring an immunotherapy treatment in a subject and methods of imaging engineered T cells in a subject. In some embodiments, the imaging is performed via Positron Emission Topography (PET). This invention further includes a chemical inducer of dimerization (CID), wherein the CID is a Bis-Trimethoprim (Bis-TMP).
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- Mechanism of Hydrocarbon Functionalization by an Iodate/Chloride System: The Role of Ester Protection
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Mixtures of chloride and iodate salts for light alkane oxidation achieve >20% yield of methyl trifluoroacetate (TFA) from methane with >85% selectivity. The mechanism of this C-H oxygenation has been probed by examining adamantane as a model substrate. These recent results lend support to the involvement of free radicals. Comparative studies between radical chlorination and iodate/chloride functionalization of adamantane afford statistically identical 3°:2° selectivities (～5.2:1) and kinetic isotope effects for C-H/C-D functionalization (kH/kD = 1.6(3), 1.52(3)). Alkane functionalization by iodate/chloride in HTFA is proposed to occur through H-atom abstraction by free radical species including Cl? to give alkyl radicals. Iodine, which forms by in situ reduction of iodate, traps alkyl radicals as alkyl iodides that are subsequently converted to alkyl esters in HTFA solvent. Importantly, the alkyl ester products (RTFA) are quite stable to further oxidation under the oxidizing conditions due to the protecting nature of the ester moiety.
- Schwartz, Nichole A.,Boaz, Nicholas C.,Kalman, Steven E.,Zhuang, Thompson,Goldberg, Jonathan M.,Fu, Ross,Nielsen, Robert J.,Goddard, William A.,Groves, John T.,Gunnoe, T. Brent
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p. 3138 - 3149
(2018/04/14)
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- Synthesis of ethyl 4,5-bis(diethoxyphosphorylmethyl)-3-furoate
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Preparative procedure for 4,5-bis(diethoxyphosphorylmethyl)-3-furoate from 4-chloromethyl-3-furoate is developed. It includes substitution of chlorine with iodine, phosphorylation by means of the Arbuzov reaction, chloromethylation of 4-(diethoxyphosphorylmethyl)-3-furoate in the position 5 of the furan ring, substitution of chlorine with iodine in the obtained chloromethyl derivative, and repeated phosphorylation with triethyl phosphite. It was found that ethyl 4-(diethoxyphosphorylmethyl)-5(chloromethyl)-3-furoate reacts with sodium diethyl phosphite by two pathways. Besides usual nucleophilic substitution leading to phosphonate, transfer of the reaction center in the position 2 of the furan ring takes place. The ambident diethylphosphite anion in this case reacts at the oxygen to give tertiary phosphite. The latter is oxidized with the air oxygen to form ethyl 2-(diethoxyphosphoryloxy)-4-(diethoxyphosphorylmethyl)-5-methyl-3-furoate. Unlike that analogous iodomethyl phosphonate is phosphorylated selectively under the conditions of the Arbuzov reaction.
- Pevzner
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- MgI2-Mediated Chemoselective Cleavage of Protecting Groups: An Alternative to Conventional Deprotection Methodologies
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The scope of MgI2 as a valuable tool for quantitative and mild chemoselective cleavage of protecting groups is described here. This novel synthetic approach expands the use of protecting groups, widens the concept of orthogonality in synthetic processes, and offers a facile opportunity to release compounds from solid supports. Amazing MgI2: Protecting groups have had a tremendous positive impact on the art of biomolecule synthesis. In a context in which the use of attractive protecting groups is often limited by harsh deprotection conditions and low chemoselective flexibility, MgI2 offers, by the execution of a very simple protocol, a fresh vision with extensive perspectives.
- Berthet, Mathéo,Davanier, Florian,Dujardin, Gilles,Martinez, Jean,Parrot, Isabelle
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supporting information
p. 11014 - 11016
(2015/11/10)
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- Highly enantioselective simmons-smith fluorocyclopropanation of allylic alcohols via the halogen scrambling strategy of zinc carbenoids
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Highly enantio- and diastereoenriched monofluorocyclopropanes were accessed via the Simmons-Smith fluorocyclopropanation of allylic alcohols using difluoroiodomethane and ethylzinc iodide as the substituted carbenoid precursors. The scrambling of halogens
- Beaulieu, Louis-Philippe B.,Schneider, Jakob F.,Charette, Andre B.
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supporting information
p. 7819 - 7822
(2013/06/27)
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- S-alkylation of thiacalixarenes: A long-neglected possibility in the calixarene family
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Despite the high nucleophilicity of sulfur atoms, thiacalixarenes have been alkylated only on oxygen atoms thus far. Using strong alkylating agents (triflates, trialkyloxonium salts), the substitution of the sulfur bridges has been successfully accomplished. The corresponding sulfonium salts of thiacalix[4]arene are formed regio- and stereoselectively as a completely new type of substitution pattern in thiacalixarene chemistry. These compounds possess interesting conformational behavior and could be used as unusual alkylating agents with uncommon selectivity.
- Kundrat, Ondrej,Eigner, Vaclav,Dvorakova, Hana,Lhotak, Pavel
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supporting information; scheme or table
p. 4032 - 4035
(2011/09/20)
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- A new method for quantifying iodine in a starch-iodine matrix
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A rapid and sensitive method for quantifying iodine in intact starch granules using gas chromatography is described with detection limits as low as 0.2% (w/w) iodine in starch. Sample preparation includes NaBH4 reduction of the various iodine species associated with starch to the colorless soluble iodide ion, followed by its quantitative derivatization to EtI using Et3O+BF4- in CH2Cl2. Identification and quantification of EtI is carried out by extraction and injection of the EtI so generated in CH2Cl2 into a gas chromatography-mass spectrometer (GC-MS). Routine quantification of EtI was then performed using GC with a flame ionization detector (GC-FID). Results for different iodine:potassium iodide ratios of the initially bound iodine and for seven different starch matrices showed that in all cases regression coefficients for the standards were high (R2 >0.96).
- Manion, Bruce A.,Holbein, Bruce E.,Marcone, Massimo F.,Seetharaman, Koushik
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experimental part
p. 2698 - 2704
(2011/02/21)
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- The design and synthesis of a novel organophosphorus compound containing the structure of both β-amino acid and β-aminophosphonate
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A novel organophosphorus compound containing the structure of both b-amino acid and b-aminophosphonate is designed and synthesized. Arbuzov reaction with P(OEt)3, the N-Boc protected iodide 3 cannot provide the desired product but 2-oxazolidinone 4 because of the neighboring-group participation of the Boc moiety. To avoid the intramolecular participation of the carbamates, the Ts protecting group is employed and the Ts-protected iodide 5 affords the target product successfully.
- Teng, Han Bing
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scheme or table
p. 810 - 812
(2011/11/13)
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- Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
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Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
- D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
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experimental part
p. 6399 - 6406
(2010/04/06)
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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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- Reactions of (triethylstannylthioalkyl)trialkoxysilanes and (triethylstannylthioalkyl)trialkoxysilatranes with methyl iodide
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Reactions of (triethylstannylthioalkyl)trimethoxysilanes Et 3SnS(CH2)nSi(OMe)3 (n = 1, 2) and (triethylstannylthioalkyl)trialkoxysilatranes Et3Sn(CH2) n Sa [hereinafter Sa = Si(O
- Sorokin,Voronkov
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experimental part
p. 2056 - 2060
(2009/04/13)
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- Multicomponent synthesis of dihydropyrimidines and thiazines
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A broad range of differently substituted dihydropyrimidines and thiazines can be efficiently prepared by using a four-component reaction between phosphonates, nitriles, aldehydes, and iso(thio)cyanates. The scope and limitations of this multicomponent reaction are fully described. Variation of all four components has been investigated. The nitrile and aldehyde inputs can be varied extensively, but variation of the phosphonate input remains limited. An interesting rearrangement leading to phosphoramidates has been observed, Furthermore, the multicomponent reaction seems to be restricted to the use of isocyanates with strongly electron-withdrawing substituents, but an interesting additional exchange reaction under microwave conditions leads to dihydropyrimidines with less electron-withdrawing substituents at N3. In addition, a diastereoselective formation of dihydropyrimidines has been observed when using a chiral aldehyde as the input. Finally, by changing the isocyanate component to an isothiocyanate, thiazines are efficiently formed instead of the corresponding thio-dihydropyrimidines.
- Vugts, Danielle J.,Koningstein, Manoe M.,Schmitz, Rob F.,De Kanter, Frans J. J.,Groen, Marinus B.,Orru, Romano V. A.
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p. 7178 - 7189
(2007/10/03)
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- Mechanism of decomposition of quasiphosphonium intermediates: Borderline SN1 character of alkyl-oxygen fission in sec-alkyloxyphosphonium salts
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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
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p. 473 - 480
(2007/10/03)
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- Acyl iodides in organic synthesis: V. Reactions with carboxylic acid esters
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Acyl iodides react with alkyl, alkenyl, and aralkyl esters derived from saturated, unsaturated, and aromatic mono- and dicarboxylic acids in the absence of a catalyst. The reaction involves cleavage of the OR bond and formation of organic iodide RI (including CH2=CHI) and one or two symmetric carboxylic acid anhydrides. Phenyl acetate reacts with benzoyl iodide to give acetyl iodide and phenyl benzoate as a result of cleavage of the (O=)C-O bond. The reaction of diethyl fumarate with acetyl iodide is accompanied by cis- trans isomerization to afford maleic anhydride. In the reactions of acetyl iodide with diethyl oxalate and diethyl malonate, CO and CO2 and CO 2 and polyketene are formed, respectively, in addition to ethyl iodide and acetic anhydride. Ethyl esters of strong organic acids, e.g., ethyl trihaloacetates, failed to react with acyl iodides under analogous conditions.
- Voronkov,Trukhina,Vlasova
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p. 357 - 359
(2007/10/03)
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- N-alkylated thiazolium salts and process for their preparation
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The present invention relates to N-alkylated thiazolium salts, to a process for their preparation and also to their use as condensation and dehydrating agents.
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- Radical Yields in the Radiolysis of Branched Hydrocarbons: Tertiary C-H Bond Rupture in 2,3-Dimethylbutane, 2,4-Dimethylpentane, and 3-Ethylpentane
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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
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p. 9240 - 9247
(2007/10/03)
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- Labeled compounds for measuring the function of the muscarinic acetylcholine nervous system
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A muscarinic acetylcholine nervous system labeled compound for positron emission tomography measurement of the present invention has a structure represented by undermentioned general formula (I): [in the formula, W represents one selected from the group consisting of groups represented by undermentioned formulae (II) and (III): (in the formulae, R represents one selected from the group consisting of an 11C-labeled ethyl group and an 11C-labeled propyl group), and in the case that W is a group represented by above-mentioned formula (II), above-mentioned formula (I) is the (+)-isomer].
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- Relative reactivity of methyl iodide to ethyl iodide in nucleophilic substitution reactions in acetonitrile and partial desolvation accompanying activation
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Through the examination of empirical correlations involving activation parameters for nucleophilic substitution of methyl iodide and of ethyl iodide, nucleophiles have been classified into three series: (1) nucleophiles with two equivalent reaction sites, (2) nucleophiles with a chlorine atom in the para-position, and (3) nucleophiles with a single reaction site. Three types of partial desolvation processes accompanying activation have been deduced on the basis of these classifications. A major factor determining the relative reactivity of methyl iodide to ethyl iodide in the substitution reaction of an anionic nucleophile having a single reaction site in acetonitrile (kMeI/kEtI) is suggested to be partial desolvation around the nucleophilic center on going from reactant to transition-state.
- Kondo, Yasuhiko,Urade, Miyuki,Yamanishi, Yukari,Chen, Xinyu
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p. 1449 - 1454
(2007/10/03)
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- Acyl iodides in organic synthesis: I. Reactions with alcohols
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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
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p. 1576 - 1578
(2007/10/03)
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- Hydroxamic acid derivatives as matrix metalloprotease (MMP) inhibitors
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Compounds of formula (I):or pharmaceutically or veterinarily acceptable salts thereof, or pharmaceutically or veterinarily acceptable solvates of either entity, wherein the broken line represents an optional bond; A is C or CH; B is CH2, O or absent; R1 and R2 are each independently selected from hydrogen, C1 to C6 alkyl optionally substituted with C1 to C4 alkoxy or phenyl, and C1 to C6 alkenyl; or, together with the carbon atom to which they are attached, form a C3 to C6 cycloalkyl group which optionally incorporates a heteroatom linkage selected from O, SO, SO2 and NR6 or which is optionally benzo-fused; R3 is hydrogen, halo, R7 or OR7; R4 is hydrogen, C1 to C4 alkyl, C1 to C4 alkoxy, trifluoromethyl or halo; R6 is hydrogen or C1 to C4 alkyl; R7 is an optionally substituted monocyclic or bicyclic ring system; m is 1 or 2; and n is 0, 1 or 2; with the proviso that B is not O when A is C; are MMP inhibitors useful in the treatment of, inter alia, tissue ulceration, wound repair and skin diseases.
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- Novel coupler for use in oxidative hair dyeing
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Couplers for hair coloring compositions for oxidative dyeing of hair are compounds of the formula (1): wherein X is selected from halogen and R2SO4; R3 is selected from C1 to C2 alkyl or hydroxyethyl; R2 is selected from C1 to C22 alkyl and C1 to C22 mono and dihydroxyalkyl; and R is selected from of C1 to C16 alkyl, C1 to C10 hydroxyalkyl, C1 to C6 alkoxyalkyl and benzyl.
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- Acyl iodides in organic synthesis: II. Reactions with acyclic and cyclic ethers
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Reaction of acyl iodides RCOI (R = Me, Ph) was studied with acyclic and cyclic ethers (Et2O, MeCHCH2(O), ClCH2CHCH 2(O), THF, O(CH2CH2)2O, EtOCH 2CH2OH, EtOCH=CH2, PhOEt]. The reaction occurred with the rupture of one or two CO bonds furnishing the corresponding iodides and esters.
- Voronkov,Trukhina,Vlasova
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p. 1579 - 1581
(2007/10/03)
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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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- Synthesis of ferrocenethiols containing oligo(phenylenevinylene) bridges and their characterization on gold electrodes
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Ferrocene-terminated oligo(phenylenevinylene) (OPV) methyl thiols have been prepared by orthogonal coupling of phenylene monomers. Ethoxy substituents on the phenyl rings improve the solubility of OPV, enabling the synthesis of longer oligomers. Self-assembled monolayers containing a mixture of a ferrocene OPV methyl thiol and a diluent alkanethiol were deposited on gold. A cyclic voltammetric study of monolayers containing oligomers of the same length with and without ethoxy solubilizing groups reveals that both solubilized and unsolubilized oligomers form well-packed self-assembled monolayers. Changing the position of the solubilizing groups on an oligomer chain does not preclude packing of the oligomer in the monolayer. Conventional chronoamperometry, which can be used to measure rate constants up to ～104 S-1, is too slow to measure the electron-transfer rate through these oligomers over distances up to 35 A. OPV bridges are expected to be highly conjugated unlike oligo(phenyleneethynylene) bridges, which may be only partially conjugated because of rotation of the phenyl rings about the ethynylene bonds. Because of its high conjugation, OPV may prove useful as a molecular wire.
- Dudek,Sikes,Chidsey
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p. 8033 - 8038
(2007/10/03)
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- Orthoamides. LIV. Contributions to the chemistry of azavinylogous orthoformic acid amide derivatives
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The azavinylogous aminalester 3 reacts with primary amines to give amidines 5 and 6. In the reaction of 3 with aniline the azavinylogous amidine 7 is produced additionally to the amidine 5c. Ethylendiamine is formylated at both aminogroups, the bis-amidine 8 thus formed is transformed to the salts 9a,b. Benzoxazole and benzimidazole can be prepared from 3 and o-aminophenol and o-phenylenediamine, resp. Carboxylic acid amides, urea, thiourea, aromatic acid hydrazides 17 and the sulfonylhydrazide 19 are formylated by 3 at nitrogen to give N-acylated formamidines 14, 16, 18, 20. From 3 and aliphatic acid hydrazides 17 and alkylhydrazines, resp., can be obtained 1,2,4-triazole 21 and 1-alkyl-1,2,4-triazoles 22a,b, resp. N.N-Dimethylcyanacetamide (32) reacts with 3 and the orthoamide 4a, resp., to give a mixture of the formylated compound 34 and the amidine 33. The reaction conditions are of low influence on the ratio in which 33 and 34 are formed. The orthoamide 4b and 32 react to afford a mixture of the amidine 35 and the enamine 36. Hydrogen-sulfide acts on 3 giving N,N-dimethylthioformamide (37). From 3 and 1-alkynes 41 can be prepared the amidines 42. Hydrolysis of 42b affords phenylpropiolaldehyde (43). The alkylation of the aminalester 3 gives rise to the formation of vinylogous amidinium salts 1c and 1d, resp., additionally is formed the amide acetal 2a. The salt 1d can also be prepared from 3 and borontrifluoride-ether. Iodide reacts with N,N-dimethylformamide acetals 12a,b in an unclear, complicated manner giving orthoesters 53, N,N-dimethylformamide, alkyliodides, alcohols, ammonium iodides 46 and carbondioxide. The action of halogens on 3 affords the salts 1a,b,c,e,f depending on the chosen stoichiometric ratio. Aromatic aldehydes are suited for trapping azavinylogous carbenes formed on thermolysis of 3; 1,3-oxazoles 69 are the reaction products. From 3 and propionaldehyde the amidine 65 can be obtained with low yield. Carbondisulfide transforms 3 to the azavinylogous salt 66. The preparation of the azavinylogous orthoamide 4a is described. The thermolysis of 3 and 4a, resp., gives rise to the formation of the triaminopyrimidine 67. Treatment of 1a with lithium diisopropylamide affords the triaminopyrazine 68, which can also be obtained by thermolysis of 3 in the presence of sodium hydride. Azavinylogous carbenes are thought to be the intermediates. Wiley-VCH Verlag GmbH, 2000.
- Kantlehner, Willi,Hauber, Michael,Haug, Erwin,Schallenmueller, Claus,Regele, Claudia
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p. 682 - 699
(2007/10/03)
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- Heterocyclic compounds for the treatment of CNS and cardiovascular disorders
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Novel aromatic bicyclic amines of formula (I) STR1 are useful in treating central nervous system disorders and cardiac arrhythmias and cardiac fibrillation.
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- Kinetic evidence for a novel, Grob-like substitution/fragmentation mechanism for the reaction of nucleophiles with trialkylammoniomethyl halides
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Kinetic evidence is presented in favor of a concerted, bimolecular mechanism for the unusual nucleophilic substitution/fragmentation reactions of iodide ion with (halomethyl)trimethylammonium salts. The relative reactivities of allyl, ethyl and methyl groups for this Grob-like reaction are also determined. Activation parameters are presented for the thermal reactions of 1-iodo-N,N,N-trimethylmethaniminium iodide (log A = 8.7. Ea = 19.0 kcal mol-1) and 1-iodo-N-allyl-N,N-dimethylmethaniminium iodide (log A = 14.6, Ea = 25.7 kcal mol-1) in acetonitrile, the latter reaction having an observed second order rate constant 39 times larger than the former at 70 °C. The results are compared with the classic data of Hughes, Ingold and Conant for SN2 reactions of alkyl halides.
- Fletcher, Michelle O.,Zhang, Li,Vu, Quyen,Dolbier Jr., William R.
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p. 1187 - 1192
(2007/10/03)
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- The Kinetics and Mechanism of the Reaction of Pyridine-N-Oxides with Alkyl Halides
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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
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p. 271 - 275
(2007/10/03)
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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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- Thermodynamic Parameters of Ethyl Radical and Rate Constants of Its Formation from Ethyl Iodide
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Equilibrium constants and rate constants of reactions EtI ? Et. + I., I. + EtI ? Et. + I2 were measured in the range 300-700 K employing the method of quasistationary isothermal pyrolysis. The molecular parameters of Et. free radical were calculated by quantum chemical ab initio procedure. The calculation results were used for estimating the thermodynamic functions of the Et. free radical. Combined experimental and calculated data provided the following values (kJ mol-1) of dissociation energy E0(Et-I) 223 ± 1, E298(Et-I) 226 ± 1 and enthalpy of formation ΔfH00(Et.) 125 ± 2, ΔfH0298(Et.) 114 ± 2.
- Skorobogatov,Dymov,Pogosyan,Chuikov-Ru
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p. 481 - 491
(2007/10/03)
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- Simple and rapid determination of the activation parameters of organic reactions by temperature-dependent NMR spectroscopy II. Application to reversible reactions
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A non-isothermal (NIT) method for evaluating the activation enthalpies and entropies of reactions in solutions was applied to several reversible reactions. This was realized by a stepwise elevation of the temperature of a reaction system using a variable-temperature apparatus comprising on NMR spectrometer and a quick collection of FID (free induction decay) at every plateau of the step. The rate from NIT experiments agreed well with the previously measured rates by the conventional methods.
- Satoh, Masahiro,Hirota, Minoru
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p. 2619 - 2624
(2007/10/03)
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- Photoproduct Characterization and Dynamics in the 248 nm Photlysis of CH3I Thin Films on Ag(111)
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The 248 nm photochemistry of methyl iodide thin films was studied using reflection absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and time-of-flight quadrupole mass spectrometry (TOF-QMS).The formation of predominantly CH2I2 and CH4 and some C2H6, CH3CH2I, CHI3 and I2 photoproducts retained in the film was characterized by RAIRS and TPD.The integrated areas of the IR absorption bands for the two major photoproducts, CH2I2 and CH4, increase to a maximum and then decrease as photolysis of the film proceeds.A cross section for the loss of CH3I by 248 nm photolysis of the film was measured to be (1.0+/-0.1)E-19 cm2, approximately 1 order of magnitude lower than the gas-phase cross section.At all laser fluences used in this study, CH3, I, and CH3I were ejected into the gas phase.The CH3 TOF distribution showed the signature of the gas-phase CH3I photodissociation dynamics-two sharp peaks corresponding to the production of iodine atoms in the I(2P3/2) and I*(2P1/2) states.The TOF distributions of I and CH3I were fit by Maxwell-Boltzmann distributions corresponding to temperatures of 1400 and 1170 K, respectively.Three other species-CH4, I2 and CH2I2-were observed in TOF-QMS, but only at higher laser fluences.It was determined that the I2 and CH2I2 species are most likely fragments of a larger molecule, perhaps a cluster species, that photodesorbs as the film becomes enriched with photoproducts.The mechanism for CH4 photoejection appears to be of a different nature.The photochemistry of methyl iodide thin films can be understood in terms of a combination of photoproceses occuring in the film and at the film surface.
- Coon, S. R.,Myli, K. B.,Grassian, V. H.
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p. 16416 - 16424
(2007/10/02)
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- The Double Carbonylation of Diiodomethane Catalysed by Rhodium Complexes
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In alcohols, ROH, in the presence of and optionally also in the presence of a tertiary phosphorus ligand PR'3, CH2I2 reacts with CO to give CH2(CO2R)2, CH2(OR)2 and RI.
- Weston, William S.,Gash, Rosslyn C.,Cole-Hamilton, David J.
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p. 745 - 746
(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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- 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
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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.
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p. 4411 - 4414
(2007/10/02)
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- Photoinduced Radical Chain Reactions between Alkylcobalt(III) Complexes and Iodide
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Cobalt-carbon bonds of various alkylcobalt(III) complexes, cis-ClO4 (R=Me, Et, or PhCH2; bipy = 2,2'-bipyridine), trans->CoMe2(L)> (L=3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and (R=Me or Et; Hdmg = dimet
- Ishikawa, Kunio,Fukuzumi, Shunichi,Goto, Tatsushi,Tanaka, Toshio
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- Diiodosilane. 2. A Multipurpose Reagent for Hydrolysis and Reductive Iodination of Ketals, Acetals, Ketones, and Aldehydes
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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.
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p. 2927 - 2938
(2007/10/02)
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- Electron-transfer processes in the electrophilic cleavage of cobalt-carbon bonds of alkylcobalt(III) complexes with iodine
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Contribution of the electron-transfer processes in the cleavage of cobalt-carbon bonds of alkylcobalt(III) complexes cis-[R2Co(bpy)2]+ (R = Me, Et, PhCH2; bpy = 2,2′-bipyridine), trans-[Me2Co(DpnH)] (DpnH = 11-hydroxy-2,3,9,10-tetramethyl-1,4,8,11-tetraazaundeca-1,3,8,10-tetraen-1- olate), and [RCo(DH)2py] (R = Me, Et, PhCH2; (DH)2 = bis(dimethylglyoximato); py = pyridine) with iodine has been studied by detecting the products that could arise only via electron-transfer processes as well as by the kinetic comparison between the electrophilic reactions of iodine with alkylcobalt(III) complexes and the electron-transfer reactions of iodine with ferrocene derivatives in acetonitrile. The coupling products of alkyl groups of dialkylcobalt(III) complexes, derived from the corresponding dialkylcobalt(IV) complexes, are obtained in the cleavage reactions of dialkylcobalt(III) complexes with iodine, with alkyl iodides being the main products. The observed second-order rate constants for the cleavage reactions of alkylcobalt(III) complexes with iodine in acetonitrile at 298 K are compared with those of electron transfer from ferrocene derivatives to iodine, based on the Marcus theory of electron transfer.
- Ishikawa, Kunio,Fukuzumi, Shunichi,Tanaka, Toshio
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p. 1661 - 1665
(2008/10/08)
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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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- New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides
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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
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p. 995 - 999
(2007/10/02)
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- Photo-cleavage of Cobalt-Carbon Bonds of Alkylcobalt(III) Complexes by Iodine with Large Quantum Yields
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Cobalt-carbon bonds of alkylcobalt(III) complexes are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced electron-transfer radical chain reactions with large quantum yields (e.g., Φ = 7.0 x 103) under low
- Fukuzumi, Shunichi,Goto, Tatsushi,Ishikawa, Kunio,Tanaka, Toshio
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p. 260 - 261
(2007/10/02)
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- 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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p. 4766 - 4776
(2007/10/02)
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- Bisphosphonic acids and esters
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The present invention relates to hitherto unknown compounds of the formula I STR1 in which R1 is a straight or branched, saturated or unsaturated aliphatic or alicyclic C1 -C10 hydrocarbon radical, an aryl or an aryl-C1 -C4 -alkyl radical, R1 if desired being unsubstituted or substituted with straight or branched C1 -C4 -alkyl, amino, C1 -C4 -alkamino, di-(C1 -C4 -alkyl)-amino, carboxy, C1 -C4 -alkoxycarbonyl, hydroxy, C1 -C4 -alkoxy, phenoxy, mercapto, C1 -C4 -alkylthio, phenylthio, halogen, trifluoromethyl; R2 stands for hydrogen, C1 -C8 -alkyl, aryl-C1 -C4 -alkyl or halogen; X is O or S, and n is an integer from 0 to 2; with the proviso that R2 cannot be hydrogen or methyl if n=O and R1 is methyl. The compounds of the invention are valuable in the human and veterinary practice.
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