Isopropyl Iodide Research Articles

Asymmetric Synthesis of Chiral Sulfimides through the O-Alkylation of Enantioenriched Sulfinamides and Addition of Carbon Nucleophiles.

Chiral sulfimides, the aza-analogues of sulfoxides, are valuable compounds in organic synthesis and medicinal chemistry. Herein, we report an efficient method for preparing chiral sulfimides from easily available enantioenriched sulfinamides. The key step of this method is a stereospecific oxygen-selective alkylation of enantioenriched sulfinamides, which is accomplished by using isopropyl iodide, K2 CO3 , and DMPU. The resulting chiral sulfinimidate esters are transformed to chiral sulfimides by the nucleophilic addition of the Grignard reagents under simple conditions. This transformation enables access to the enantioenriched diaryl or dialkyl sulfimides bearing two similar carbon substituents, which are difficult to synthesize by previous methods.

Asymmetric Synthesis of Chiral Sulfimides through the O‐Alkylation of Enantioenriched Sulfinamides and Addition of Carbon Nucleophiles

AbstractChiral sulfimides, the aza‐analogues of sulfoxides, are valuable compounds in organic synthesis and medicinal chemistry. Herein, we report an efficient method for preparing chiral sulfimides from easily available enantioenriched sulfinamides. The key step of this method is a stereospecific oxygen‐selective alkylation of enantioenriched sulfinamides, which is accomplished by using isopropyl iodide, K2CO3, and DMPU. The resulting chiral sulfinimidate esters are transformed to chiral sulfimides by the nucleophilic addition of the Grignard reagents under simple conditions. This transformation enables access to the enantioenriched diaryl or dialkyl sulfimides bearing two similar carbon substituents, which are difficult to synthesize by previous methods.

Relativistic and vibrational effects on the electronic structure of isopropyl iodide

Relativistic and vibrational effects on the electronic wavefunctions of molecular isopropyl iodide are investigated, using the electron momentum spectroscopy measurements in combination with theoretical calculations. The branching ratio of the electron-impact ionization between the outmost molecular orbitals 5a'' and 8a' shows a remarkable spin–orbit coupling relativistic effect. Both the relativistic and vibrational effects are found in the low momentum region of the electron momentum profile of 7a' orbital, while the momentum profiles of 6a', 4a'', 3a'' and 2a'' orbitals only indicate the vibrational effect. For the inner valence orbitals, the relativistic effects on the momentum profiles of 3a' and 2a' are observed while the vibrational effects are absent. But for 1a'' and 1a' orbitals neither the relativistic nor vibrational effects appear.

Strong dual-state emission of unsymmetrical and symmetrical thiazolothiazole-bridged imidazolium salts

A novel thiazolothiazole-bridged imidazole derivative (1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 using n-propyl iodide generated unsymmetrically or symmetrically alkylated thiazolothiazole-bridged imidazolium salts with good water solubility and remarkably strong emission in solution. Furthermore, the replacement of iodide counter-anion by triflate or bis(trifluoromethane sulfonyl)imide achieved remarkably strong emission in solid state and in solution as well as good water solubility. The strong fluorescence of dicationic salts with triflate and NTf2– counter-anions in solid state can be ascribed to their twisted and rigid structures induced by interionic C−H···F hydrogen bonding.

Influence of growth conditions from metalorganic compounds on the preparation of n-CdTe epitaxial layers using isopropyl iodide

The dependence of iodine incorporation in CdTe layers on the deposition conditions during metalorganic vapor phase epitaxy is investigated. The growth of the layers was carried out from dimethylcadmium and diethyltellurium in the hydrogen flow in a vertical reactor with a hot wall condition at a total pressure of 20 kPa. The total iodine concentration was determined by secondary ion mass spectrometry, the electrically active concentration was determined from the Hall effect measurement. The iodine incorporation depends on the crystallographic orientation of the substrate (were studied (100), (310), (111)A, (111)B, (211)A and (211)B), the concentration of the doping precursor (flux range 5·10-8-3·10-6 mol/min), the mole ratio of organometallic compounds (DMCd/DETe = 0.25-4), growth temperature (335-390oC) and the walls of the reactor above the pedestal (hot wall zone 290-320oC). The total iodine concentration reached 5·1018 cm-3 and the activation efficiency was ~4%. After thermal annealing in cadmium vapor at 500oC the activation efficiency was ~100%. Keywords: epitaxial layers, metalorganic vapour phase epitaxy, CdTe, iodine doping, isopropyl iodide, thermal annealing.

Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy

Conical intersections between electronic states often dictate the chemistry of photoexcited molecules. Recently developed sources of ultrashort extreme ultraviolet (XUV) pulses tuned to element-specific transitions in molecules allow for the unambiguous detection of electronic state-switching at a conical intersection. Here, the fragmentation of photoexcited iso-propyl iodide and tert-butyl iodide molecules (i-C3H7I and t-C4H9I) through a conical intersection between 3Q0/1Q1 spin–orbit states is revealed by ultrafast XUV transient absorption measuring iodine 4d core-to-valence transitions. The electronic state-sensitivity of the technique allows for a complete mapping of molecular dissociation from photoexcitation to photoproducts. In both molecules, the sub-100 fs transfer of a photoexcited wave packet from the 3Q0 state into the 1Q1 state at the conical intersection is captured. The results show how differences in the electronic state-switching of the wave packet in i-C3H7I and t-C4H9I directly lead to differences in the photoproduct branching ratio of the two systems.

Trace determination of mutagenic alkyl toluenesulfonate impurities via derivatization headspace–GC/MS in an active pharmaceutical ingredient of a candidate drug

This study aims to optimize sodium iodide (NaI) derivatization headspace–GC/MS described in European Pharmacopoeia by using vitamin C as an alternative antioxidant for the determination of mutagenic alkyl toluenesulfonate impurities in an active pharmaceutical ingredient (API) of a candidate drug with an artemisinin derivative. Alkyl toluenesulfonates are transformed into their corresponding alkyl iodides (methyl iodide, ethyl iodide, propyl iodide, and isopropyl iodide) by utilizing the derivatization reagent NaI. Results show that the MS response of methyl iodide is a critical indicator of method robustness because of the deteriorating effects of methyl iodide on stability when sodium thiosulfate is used as an antioxidant originally described in the pharmacopoeia. With vitamin C as a newly developed antioxidant, the robustness of this method is improved significantly. The optimized method is further validated and applied successfully for the quality control and safety of the API of an artemisinin derivative.

An unusual reaction of a Reissert compound involving alkylation, rearrangement, SNAr and SET processes

Reaction of isoquinoline Reissert compound 1 with NaH and then isopropyl iodide in DMF at 22 °C led to four isolated products. Ketone 3 is the expected product of the well-known rearrangement of the intermediate Reissert anion. Cyano lactam 4 results from SNAr intramolecular displacement of the fluoride ion from the activated aroyl moiety of the anion. Isopropyl lactam 5 is proposed to result from a SET (single electron transfer) process via formation of the radical anion of 4, subsequent loss of the cyanide ion, and coupling of the resultant radical with isopropyl radicals formed via copper used to “stabilize” the alkyl iodide. The expected alkylated product 2 is also formed via a SET process involving electron transfer from the Reissert anion to 4, leading to the Reissert radical. Use of “non-stabilized” bromide or iodide led to 3 and 4, but did not produce 2 or 5.

Affinity of charcoals for different forms of radioactive organic iodine

During a serious nuclear reactor accident a large fraction of the radioactive iodine in the fuel can escape from the core and subsequently from the plant. While the noble gases in reactor fuel are more mobile than iodine, the iodine is often of greater concern as its chemistry and biology causes it to be more radiotoxic. Iodine has the potential to be re-concentrated in vivo in the thyroid. Filters containing charcoals are used both under normal operating conditions and during emergencies to retain iodine species, they are used in environmental sampling to estimate radioactive iodine and in respiratory protection systems such as air purifying filter respirators. During a nuclear accident iodine can exist in many forms. As the formation of organic iodine compounds other than methyl iodide has been observed in nuclear plants it can be reasoned that a failure of a charcoal to retain other organoiodines than methyl iodide could have adverse consequences. In this paper, the ability of different charcoals to capture various forms of radioactive organic iodine compounds has been explored. Besides elemental iodine used as reference methyl, chloromethyl, ethyl and isopropyl iodides have been studied together with iodoacetylene.

Alkylation of 3-methyl-1H-acenaphtho[5,6-de]pyridazine

Alkylation of 3-methyl-1Н-acenaphtho[5,6]pyridazine with methyl and propyl iodides as well as with benzyl chloride in alkaline medium leads to the formation of the corresponding both N- and С-substituted pyridazine derivatives and also to the dimerization product of the initial compound. The ratio of obtained compounds depends on the used hydride, reaction temperature, and solvent.

催化量碘代烷烃促进下合成3,5-二取代异噁唑啉

研究了端基烯烃和醛肟在氧化剂过硫酸氢钾和催化量碘代烷烃作用下的[3+2] 环合反应, 合成了一系列具有良好产率及区域选择性的3,5-二取代异噁唑啉化合物. 反应中, 碘代烷烃先经过氧化分解产生了活泼的次碘酸, 再依次与醛肟和烯烃经亲电加成反应生成五元杂环碘代中间体, 该中间体通过消除反应得到3,5-二取代异噁唑啉化合物. 考察了反应条件的影响, 提出了可能的反应机理, 为合成3,5-二取代异噁唑啉化合物提供了新方法.

Rate constants of electron attachment to alkyl iodides measured by photoionization electron attachment ion mobility spectrometry (PI-EA-IMS)

The photoionization electron attachment ion mobility spectrometry (PI-EA-IMS), with photoelectrons formed by photoionization of organic compound like acetone, has been developed to study electron attachment reactions. With this apparatus, the rate constants for electron attachment to alkyl iodides including ethyl iodide (C2H5I), 1-propyl iodide (1-C3H7I), 1-butane iodide (1-C4H9I) and 2-propyl iodide (2-C3H7I) have been determined over the average electron energy from 0.29 to 0.96eV. The rate constants are in the order of magnitude of ∼10−9cm3molecule−1s−1. The experimental measurements show that for straight-chain alkyl iodides, the values of the rate constants follow the order of: k(C2H5I)<k(1-C3H7I)≈k(1-C4H9I) which can be explained by the energy threshold for the formation of iodine anion via dissociative electron attachment. For the isomers, 2-C3H7I has a lower rate constant than 1-C3H7I which may be caused by the effect of branched chain.

Electron Momentum Spectroscopy of Valence Orbitals of n-Propyl Iodide: Spin-Orbit Coupling Effect and Intramolecular Orbital Interaction

The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SAC-CI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ(C,H)6-311G** (I). The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.

Silver-Mediated Mild Oxidation of Nitrogen-Containing Heteroaryl-2-methanols to Esters

Oxidation of nitrogen-containing heteroaryl-2-methanols to esters with Ag2O and isopropyl iodide is reported. This methodology is very mild and can tolerate many functional groups.

A Novel Method for the Synthesis of Latanoprost

Latanoprost is a kind of PGF2α analogues, which is now one of the first-choice drugs in the clinic for open angle glaucoma and ocular hypertension. However, the previous synthetic methods have problems of long steps, low yield and diffi- cult separation of isomeric impurities. Herein, we report a novel method for the synthesis of latanoprost in ten steps. Benzoyl Corey lactone as starting material was oxidized to form corresponding aldehyde by Dess-Martin oxidation. The ω side chain was bonded by improving Horner-Wadsworth-Emmons reaction with dimethyl(2-oxo-4-phenylbutyl)phosphonate and lithium chloride, and reduced with (-)-diisopinocampheyl chloroborane at -30 ℃ because of its greater selectivity towards the production of desired S-isomer (95%). The deprotection step wherein the protecting group of benzoyl on the hydroxyl group of the cyclopentane ring was removed, was preferably carried out by potassium carbonate in methanol. The hydrogenation of double bond in ω side chain was carried out by using 5% palladium-carbon as catalyst. The tetrahydropyranyl (THP) group was used for the protection of the diol with p-toluenesulfonic acid as catalyst. Latanoprost lactol was obtained by reducing the lactone with diisobutylaluminum hydride (DIBAL) at -78 ℃. α side chain of latanoprost was bonded by Wittig reaction with 4-carboxybutyl triphenylphosphoium bromide and NaHMDS forming phosphorus ylide. The carboxylic acid was alky- lated with isopropyl iodide in the presence of 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), and then removed the THP protect- ing groups with pyridinium 4-toluenesulfonate (PPTS). Latanoprost was separated from two isomers of 15(S)-latanoprost and 5,6-trans-latanoprost after purification by normal-phase high performance liquid chromatography. Thus latanoprost was ob- tained with high purity of 99.91% and high overall yield of 19.2%, and the structure was characterized by 1 H NMR, 13 C NMR, IR and HRMS. Compared with the previous routes, the current synthesis is shorter, more practical, and more suitable for large-scale preparation.

Formation of organic iodides from containment paint ingredients caused by gamma irradiation

The formation of volatile alkyl iodides other than methyl iodide during a serious nuclear reactor accident may have radiological significance. The hypothesis that radioactive alkyl iodides, other than methyl iodide, could form from paint solvents under the conditions of a serious nuclear accident in light water reactors (under boiling water reactor (BWR) and pressurised water reactor (PWR) conditions) was tested using stable elemental iodine, a gamma irradiator and gas chromatography equipment. It was found that methyl and isopropyl iodides were formed from the texanol ester, which is used in many modern water-based paints. Methyl, ethyl, propyl and butyl iodides were formed from a hydrocarbon solvent (white spirit) commonly used in paint products used in the past. These results suggest that further work on the formation and behaviour of the higher alkyl iodides (containing more than one carbon atom) under the conditions of a serious nuclear accident is justified.

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 C(n)H(n+2)(OH)(n) are carbonylated to the corresponding C(n+1) mono-carboxylic acids.

Mechanistic investigation of S N2 dominated gas phase alkyl iodide reactions

The competition between substitution (S N2) and elimination (E2) has been studied for the reactions of methyl, ethyl, isopropyl, and tert-butyl iodide with Cl −, CN −, and HS − in the gas phase. Previous studies have shown a dominance of the S N2 mechanism for sulfur anions and for some cyanide–alkyl iodide reactions. Although our results support this conclusion for the reactions studied, they reveal that competition between the S N2 and E2 pathways exists for the isopropyl reactions. Steric and electronic effects, upon alkyl group substitution, produce looser and less stable S N2 transition states, however, they can favor the E2 process. These opposing effects on barrier heights produce E2/S N2 competition as steric hindrance increases around the α-carbon, however the relative differences in intrinsic barrier heights lead to significantly different branching ratios. This interpretation is discussed in terms of reaction efficiencies, kinetic isotope effects, linear basicity–reactivity relationships, electrostatic models, and transition state looseness parameters.

Dissociation Dynamics of Energy Selected, Propane, and i-C3H7X+ Ions by iPEPICO: Accurate Heats of Formation of i-C3H7+, i-C3H7Cl, i-C3H7Br, and i-C3H7I

The dissociation dynamics of energy selected i-C(3)H(7)X (X = H, Cl, Br, and I) ions have been investigated by imaging photoelectron-photoion coincidence (iPEPICO) spectroscopy using synchrotron radiation from the X04DB VUV beamline in the Swiss Light Source of the Paul Scherrer Institut. The 0 K dissociation energy (E(0)) for i-C(3)H(8) was determined to be 11.624 ± 0.002 eV. This leads to a 298 K isopropyl ion heat of formation of 805.9 ± 0.5 kJ mol(-1). The Δ(f)H(298K)°(i-C(3)H(7)(+)) combined with the measured 0 K onsets for i-C(3)H(7)(+) formation from isopropyl chloride (11.065 ± 0.004 eV), isopropyl bromide (10.454 ± 0.008 eV), and isopropyl iodide (9.812 ± 0.008 eV) yields the 298 K isopropyl chloride, bromide, and iodide heats of formation of -145.7 ± 0.7, -95.6 ± 0.9, and -38.5 ± 0.9 kJ mol(-1), respectively. These values provide a significant correction to literature values and reduce the error limits. Finally, the new i-C(3)H(7)(+) heat of formation leads to a predicted adiabatic ionization energy for the isopropyl radical of 7.430 ± 0.012 eV and a 298 K proton affinity for propene of 744.1 ± 0.8 kJ mol(-1).

(E)-3-Propoxymethyl-idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one monohydrate.

The title compound, C15H16N2O2·H2O, was synthesized via the alkyl­ation of 3-hydroxy­methyl­idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one with n-propyl iodide in the presence of sodium hydroxide. The organic mol­ecule and the water mol­ecule both lie on a crystallographic mirror plane. In the crystal structure, inter­molecular O—H⋯O and O—H⋯N hydrogen bonds link the components into extended chains along [100].