Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) chalcogenides and use of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl)sulfone in heterocyclization with primary amines

Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfide and selenide with hydrogen peroxide in chloroform/acetic acid or acetic acid affords previously unknown E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfoxide, selenoxide, and sulfone. The reaction of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfone with primary amines in ethanol in the presence of NaHCO₃ or Na₂CO₃ is found to lead not only to heterocyclization but also to alcoholysis of the chloromethylidene groups in the intermediate bis(chloromethylidene) derivatives of thiomorpholine‐1,1‐dioxides to afford N‐organyl‐2(E),6(E)‐bis(ethoxymethylidene) thiomorpholine‐1,1‐dioxides as final products.     

Synthesis and Antibacterial Activity of Some 3,5‐Diphenyl and 1,3,5‐Triphenyl‐2‐pyrazolines

Some new 3,5‐diphenyl and 1,3,5‐triphenyl‐2‐pyrazolines derivatives were synthesized by reacting 1,3‐diphenyl‐2‐propen‐1‐ones with hydrazine hydrates and phenyl hydrazine in ethanol. The structural elucidation of the compounds was performed by IR, ¹H NMR and elemental analysis. All examined compounds showed appreciable antibacterial activity.     

Microsynthesis and mass spectral study of Chemical Weapons Convention related 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides

Chemical Weapons Convention (CWC)‐related compounds where the phosphorus atom is part of a ring have very limited representation in mass spectral libraries and the open literature. Here we report electron ionization (EI), chemical ionization (CI) and electrospray ionization tandem mass spectrometry (ESI‐MSⁿ) spectra and retention indices for 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides (alkyl C₁ to C₃) which are new cyclic chemicals covered under the CWC. The EI mass spectra show a pattern of ion fragmentation that is similar to that of other cyclic phosphonates in that loss of the alkylphosphonic acid as a neutral loss is more important than the presence of the protonated alkylphosphonic acid. In contrast to other cyclic phosphonates, the 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides show almost no protonated alkylphosphonic acid and as a result the spectra do not carry the same distinctive signature of the phosphorus–carbon bond that is required for the chemical to be covered under the CWC. Copyright © 2008 John Wiley & Sons, Ltd.     

两类三组份反应产物：1,3-恶嗪及嘧啶-2-酮类化合物的质谱学行为研究

电喷雾质谱被应用于分辨2-氨基-1,3-恶嗪及六氢化-4-苯基-吡喃[2,3-d]嘧啶-2-酮的杂环结构。两类化合物均为三组份反应的产物,且其杂环的结构很难用NMR判断。实验首次系统研究了两类化合物的质谱学行为（包括氘代实验和高分辨质谱研究）,发现前者在CID实验中丢失CH2N2和HCNO,而后者为直接丢失尿素。这些特征丢失为该类衍生物的结构判断,尤其是高通量的合成产物分析提供了重要的依据。     

Synthesis,structure and biological activity studies of 2‐[(1H‐1,2,4‐triazol‐1‐yl)methyl]‐1‐aryl)‐3‐ferrocenyl prop‐2‐en‐1‐one derivatives

Fifteen new ferrocene derivatives containing 1H‐1,2,4‐triazole moiety were synthesized in various yields by the condensation of ferrocenecarboxaldehyde with 1‐aryl‐3‐(1H‐1,2,4‐triazo‐1‐yl)‐propen‐1‐ones in toluene. Their structures have been confirmed by ¹H NMR, IR, MS and elemental analysis. In addition, the crystal structure of 4l was determined. The antifungal and plant growth regulatory activities of the title compounds are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

OH‐Initiated Photooxidations of 1‐Pentene and 2‐Methyl‐2‐propen‐1‐ol: Mechanism and Yields of the Primary Carbonyl Products

The products of the gas‐phase reactions of OH radicals with 1‐pentene and 2‐methyl‐2‐propen‐1‐ol (221MPO) at T=298±2 K and atmospheric pressure were investigated by using a 4500 L atmospheric simulation chamber that was built especially for this work. The molar yield of butyraldehyde was 0.74±0.12 mol for the reaction of 1‐pentene. This work provides the first product molar yield determination of formaldehyde (0.82±0.12 mol), 1‐hydroxypropan‐2‐one (0.84±0.13 mol), and methacrolein (0.078±0.012 mol) from the reaction of 221MPO with OH radicals. The mechanism of this reaction is discussed in relation to the experimental results. Additionally, taking into consideration the complex mechanism, the rate coefficients of the reactions of OH with formaldehyde, 1‐hydroxypropan‐2‐one, and methacrolein were derived at atmospheric pressure and T=298±2 K.; the obtained values were (8.9±1.6)×10^?12, (2.4±1.4)×10^?12, and (22.9±2.3)×10^?12 cm³ molecule^?1 s^?1, respectively.     

Analysis of α‐acyloxyhydroperoxy aldehydes with electrospray ionization–tandem mass spectrometry (ESI‐MSn)

A series of α‐acyloxyhydroperoxy aldehydes was analyzed with direct infusion electrospray ionization tandem mass spectrometry (ESI/MSⁿ) as well as liquid chromatography coupled with the mass spectrometry (LC/MS). Standards of α‐acyloxyhydroperoxy aldehydes were prepared by liquid‐phase ozonolysis of cyclohexene in the presence of carboxylic acids. Stabilized Criegee intermediate (SCI), a by‐product of the ozone attack on the cyclohexene double bond, reacted with the selected carboxylic acids (SCI scavengers) leading to the formation of α‐acyloxyhydroperoxy aldehydes. Ionization conditions were optimized. [M + H]⁺ ions were not formed in ESI; consequently, α‐acyloxyhydroperoxy aldehydes were identified as their ammonia adducts for the first time. On the other hand, atmospheric‐pressure chemical ionization has led to decomposition of the compounds of interest. Analysis of the mass spectra (MS² and MS³) of the [M + NH₄]⁺ ions allowed recognizing the fragmentation pathways, common for all of the compounds under study. In order to get detailed insights into the fragmentation mechanism, a number of isotopically labeled analogs were also studied. To confirm that the fragmentation mechanism allows predicting the mass spectrum of different α‐acyloxyhydroperoxy aldehydes, ozonolysis of α‐pinene, a very important secondary organic aerosol precursor, was carried out. Spectra of the two ammonium cationized α‐acyloxyhydroperoxy aldehydes prepared with α‐pinene, cis‐pinonic acid as well as pinic acid were predicted very accurately. Possible applications of the method developed for the analysis of α‐acyloxyhydroperoxy aldehydes in SOA samples, as well as other compounds containing hydroperoxide moiety are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Gas‐fragmentation study of the novel synthetic zwitterionic drug 3‐methyl‐9‐(2‐oxa‐2λ5‐2H‐1,3,2‐oxazaphosphorine‐2‐cyclohexyl)‐3,6,9‐triazaspiro[5,5]undecane chloride (SLXM‐2) by electrospray ionization tandem mass spectrometry

The zwitterionic drug 3‐methyl‐9‐(2‐oxa‐2λ5‐2H‐1,3,2‐oxazaphosphorine‐2‐cyclohexyl)‐3,6,9‐triazaspiro[5,5]undecane chloride (SLXM‐2) is a novel synthetic compound which has shown anticancer activity and low toxicity in vivo. In this study, the various gas‐phase fragmentation routes were analyzed by electrospray ionization mass spectrometry (positive ion mode) in conjunction with tandem mass spectrometry (ESI‐MSⁿ) for the first time. In ESI‐MS the fragment ion at m/z 289 (base peak) was formed by loss of the chlorine anion from the zwitterionic precursor SLXM‐2. The fragment ion at m/z 232 was formed from the ion at m/z 289 by loss of 1‐methylaziridine. The detailed gas‐phase collision‐induced dissociation (CID) fragmentation mechanisms obtained from the various precursor ions extracted from the zwitterionic SLXM‐2 drug was obtained by tandem mass spectrometry analyses. Copyright © 2010 John Wiley & Sons, Ltd.     

Collision‐induced dissociation study of poly(2‐ethyl‐2‐oxazoline) using survival yields and breakdown curves

Poly(2‐ethyl‐2‐oxazoline), a synthetic polymer was analysed by mass spectrometry using different ion sources. Two distributions could be identified in the mass spectra which related to two different polymer series (one with hydrogen and hydroxyl end‐groups and the other with methyl and hydroxyl end‐groups). The fragmentation behaviour of the protonated oligomers was studied in a quadrupole time‐of‐flight mass spectrometer (MS) with electrospray, atmospheric pressure chemical ionization and direct analysis in real time soft ionization techniques. Three product ion series were identified in the MS/MS spectra independently of the ion source used. Based on the results, a mechanism was proposed for the dissociation by means of the accurate mass of the product ions, pseudo MS³ experiments and the energy dependence of the product ion intensity, i.e. breakdown curves. The survival yield method was used to highlight the correlation between the size of the oligomers and the laboratory frame collision energy. Copyright © 2012 John Wiley & Sons, Ltd.     

卜啉与1,2-(1-吖啶-10’-基-2-氮-2-甲基-环丙-1,3-基)富勒烯非共价体的合成与表征

1,2-（1-Acridin-10＇-yl-2-aza-2-methylprop-1,3-ylene）fullerene was synthesized firstly and characterized by UV-Vis, ^1H NMR, ^13C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stable complex with zinc tetraphenylporphyrin via the axial ligation. The steady state fluorescence studies show efficient quenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C60.     

Sequential Intramolecular Diels–Alder Reaction of 3‐Heteroaryl‐2‐propenylamides of Ethenetricarboxylate

The reaction of 1,1,2‐ethenetricarboxylic acid 1,1‐diethyl ester with E‐3‐(2‐furyl)‐2‐propenylamines under the amide condensation conditions (EDCI/HOBt/Et₃N) on heating at 80–110°C afforded cis‐fused tricyclic compounds, furo[2,3‐f]isoindoles as major product. On the other hand, the reaction with E‐3‐(3‐furyl)‐2‐propenylamines afforded trans‐fused tricyclic compounds predominantly. The formation of amide/[4 + 2] cycloaddition/hydrogen‐shift reactions proceed sequentially. The observed stereoselectivity of the fused rings has been investigated by the density functional theory calculations. The reaction of 1,1,2‐ethenetricarboxylic acid 1,1‐diethyl ester with 3‐(3‐pyridinyl)‐2‐propen‐1‐amine under the amide condensation conditions afforded HOBt‐incorporated 3,4‐trans‐pyrrolidine selectively. The chemoselectivity and stereoselectivity of the reactions with (3‐heteroaryl)‐2‐propen‐1‐amines depend on the nature of heteroarenes.     

Dimethyldioxirane epoxidation of 3‐aryl‐1‐(3‐coumarinyl)propen‐1‐ones

Regioselective epoxidation of 3‐aryl‐1‐(3‐coumarinyl)propen‐1‐ones 1–10 by isolated dimethyldioxirane afforded the appropriate epoxides 11–20 in high (76–87%) yields.     

Electron ionization and electrospray ionization mass spectrometric study of a series of isomeric N‐chloro(or bromo)benzyl‐substituted (E)‐2′(3′‐ or 4′)‐hydroxy‐4‐stilbazole halides

The electron ionization (EI) mass spectra and electrospray ionization (ESI) mass spectra of a series of isomeric N‐chlorobenzyl‐ and N‐bromobenzyl‐substituted (E)‐2′(3′ or 4′)‐hydroxy‐4‐stilbazole chlorides and bromides (1–12) were recorded. The fragmentation pathways of all of the compounds and the characteristic fragment ions formed by EI‐MS were studied by means of B/E and B²/E constant linked‐scanning techniques. The formation of ions originating from preionization reactions, characteristic of quaternary halides under EI‐MS conditions, such as the elimination of chloro‐ or bromobenzyl halides, dehydrohalogenation or substitution reactions, is explained. As soft ionization methods cause no such degradation reactions, the ESI‐MS spectra of the studied compounds were also obtained for comparison. We thus demonstrated the applicability of EI‐MS even in cases when preionization takes place, as long as such secondary processes are properly accounted for. Copyright © 2010 John Wiley & Sons, Ltd.     

Planar 2‐Pyridyl‐1,2,3‐triazole Derived Metallo‐ligands: Self‐assembly with PdCl2 and Photocatalysis

Self‐assembled metallosupramolecular architectures (MSAs) with built‐in functionalities such as light‐harvesting metal centers are a promising approach for developing emergent properties within discrete molecular systems. Herein we describe the synthesis of two new but simple “click” ligands featuring a bidentate 2‐pyridyl‐1,2,3‐triazole chelate pocket linked to a monodentate pyridyl (either 3‐ or 4‐substituted, L1 and L2 ) unit. The ligands and the corresponding four Pd^IIand Pt^IImetallo‐ligands ( Pd1 , Pd2 , Pt1 and Pt2 ) were synthesized and characterized using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI‐MS), and X‐ray crystallography. Solid‐state characterization of the series of ligands and metallo‐ligands revealed that these compounds display a co‐planar conformation of all the aryl units. The Pt^IIcontaining metallo‐ligands ( Pt1 and Pt2 ) were found to assemble into square ( Sqr ) and triangular ( Tri ) shaped architectures when combined with neutral PdCl₂ linker units. Additionally, the ability of the Pt^IImetallo‐ligands and Tri to photocatalyze the cycloaddition of singlet oxygen to anthracene was investigated.     

Synthesis and spectral properties of 2‐methylthio‐3H‐7‐[(o‐; m‐ and p‐substituted)phenoxy]‐4‐(p‐substituted‐phenyl)‐[1,5]benzodiazepines

A series of eleven new 2‐methylthio‐3H‐7‐[(o‐; m‐ and p‐substituted) phenoxy]‐4‐(p‐substituted‐phenyl)‐[1,5]benzodiazepines, which have potentially useful pharmacological activities, has been synthesized by condensing the 4‐[(o‐; m‐ and p‐R₁)phenoxy]‐1,2‐phenylendiamines with 3,3‐dimercapto‐1‐(p‐R₂‐phenyl)‐2‐propen‐1‐one. Afterward the lH‐[1,5]benzodiazepine‐2‐thiones obtained were treated with sodium hydride and methyl iodide. The structure of all products was corroborated by ir, ¹H nmr, ¹³C nmr and ms.     

Dimethyldioxirane as a new and effective oxidation agent for the epoxidation of α,ω‐di(isobutenyl)polyisobutylene: A convenient synthesis of α,ω‐di(2‐methyl‐3‐hydroxypropyl)‐polyisobutylene

The synthesis and characterization of α,ω‐di(2‐methyl‐2,3‐epoxypropyl)polyisobutylene are reported. The epoxidation of α,ω‐di(isobutenyl)polyisobutylene was achieved at room temperature with dimethyldioxirane, which proved to be a very effective reagent for epoxidation without the formation of byproducts. A very good agreement was found for the conversion determined by ¹H NMR and matrix‐assisted laser desorption/ionization mass spectrometry (MALDI HMS). The epoxy end groups were converted quantitatively into aldehyde termini with zinc bromide as a catalyst. The aldehyde groups were then reduced with LiAlH₄ into primary hydroxyl functions to obtain α,ω‐di(2‐methyl‐3‐hydroxylpropyl)polyisobutylene with high efficiency. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3974–3986, 2002     

Mass spectrometry of rhenium complexes: a comparative study by using LDI‐MS,MALDI‐MS,PESI‐MS and ESI‐MS

A group of rhenium (I) complexes including in their structure ligands such as CF₃SO₃‐, CH₃CO₂‐, CO, 2,2′‐bipyridine, dipyridil[3,2‐a:2′3′‐c]phenazine, naphthalene‐2‐carboxylate, anthracene‐9‐carboxylate, pyrene‐1‐carboxylate and 1,10‐phenanthroline have been studied for the first time by mass spectrometry. The probe electrospray ionization (PESI) is a technique based on electrospray ionization (ESI) that generates electrospray from the tip of a solid metal needle. In this work, mass spectra for organometallic complexes obtained by PESI were compared with those obtained by classical ESI and high flow rate electrospray ionization assisted by corona discharge (HF‐ESI‐CD), an ideal method to avoid decomposition of the complexes and to induce their oxidation to yield intact molecular cation radicals in gas state [M]^+. and to produce their reduction yielding the gas species [M]^–.. It was found that both techniques showed in general the intact molecular ions of the organometallics studied and provided additional structure characteristic diagnostic fragments. As the rhenium complexes studied in the present work showed strong absorption in the UV–visible region, particularly at 355 nm, laser desorption ionization (LDI) mass spectrometry experiments could be conducted. Although intact molecular ions could be detected in a few cases, LDI mass spectra showed diagnostic fragments for characterization of the complexes structure. Furthermore, matrix‐assisted laser desorption ionization (MALDI) mass spectra were obtained. Nor‐harmane, a compound with basic character, was used as matrix, and the intact molecular ions were detected in two examples, in negative ion mode as the [M]^–. species. Results obtained with 2‐[(2E)‐3‐(4‐tert‐buthylphenyl)‐2‐methylprop‐2‐enylidene] malononitrile (DCTB) as matrix are also described. LDI experiments provided more information about the rhenium complex structures than did the MALDI ones. Copyright © 2012 John Wiley & Sons, Ltd.     

The transformation from 2°‐amine to 3°‐amine of cyclam ring alters the fragmentation patterns of 1‐tosylcytosine‐cyclam conjugates

The novel N‐1‐sulfonylcytosine‐cyclam conjugates 1 and 2 conjugates are ionized by electrospray ionization mass spectrometry (ESI MS) in positive and negative modes (ES⁺ and ES⁻) as singly protonated/deprotonated species or as singly or doubly charged metal complexes. Their structure and fragmentation behavior is examined by collision induced experiments. It was observed that the structure of the conjugate dictated the mode of the ionization: 1 was analyzed in ES⁻ mode while 2 in positive mode. Complexation with metal ions did not have the influence on the ionization mode. Zn²⁺ and Cu²⁺ complexes with ligand 1 followed the similar fragmentation pattern in negative ionization mode. The transformation from 2°‐amine in 1 to 3°‐amine of cyclam ring in 2 leads to the different fragmentation patterns due to the modification of the protonation priority which changed the fragmentation channels within the conjugate itself. Cu²⁺ ions formed complexes practically immediately, and the priority had the cyclam portion of the ligand 2 . The structure of the formed Zn²⁺ complexes with ligand 2 depended on the number of 3° amines within the cyclam portion of the conjugate and the ratio of the metal:ligand used. The cleavage of the cyclam ring of metal complexes is driven by the formation of the fragment that suited the coordinating demand of the metal ions and the collision energy applied. Finally, it was shown that the structure of the cyclam conjugate dictates the fragmentation reactions and not the metal ions.     

The effect of temperature on the stability of compounds used as UV‐MALDI‐MS matrix: 2,5‐dihydroxybenzoic acid, 2,4,6‐trihydroxyacetophenone, α‐cyano‐4‐hydroxycinnamic acid, 3,5‐dimethoxy‐4‐hydroxycinnamic acid,nor‐harmane and harmane

The thermal stability of several commonly used crystalline matrix‐assisted ultraviolet laser desorption/ionization mass spectrometry (UV‐MALDI‐MS) matrices, 2,5‐dihydroxybenzoic acid (gentisic acid; GA), 2,4,6‐trihydroxyacetophenone (THA), α‐cyano‐4‐hydroxycinnamic acid (CHC), 3,5‐dimethoxy‐4‐hydroxycinnamic acid (sinapinic acid; SA), 9H‐pirido[3,4‐b]indole (nor‐harmane; nor‐Ho), 1‐methyl‐9H‐pirido[3,4‐b]indole (harmane; Ho), perchlorate of nor‐harmanonium ([nor‐Ho + H]⁺) and perchlorate of harmanonium ([Ho + H]⁺) was studied by heating them at their melting point and characterizing the remaining material by using different MS techniques [electron ionization mass spectrometry (EI‐MS), ultraviolet laserdesorption/ionization‐time‐of‐flight‐mass spectrometry (UV‐LDI‐TOF‐MS) and electrospray ionization‐time‐of‐flight‐mass spectrometry (ESI‐TOF‐MS)] as well as by thin layer chromatography analysis (TLC), electronic spectroscopy (UV‐absorption, fluorescence emission and excitation spectroscopy) and ¹H nuclear magnetic resonance spectroscopy (¹H‐NMR). In general, all compounds, except for CHC and SA, remained unchanged after fusion. CHC showed loss of CO₂, yielding the trans‐/cis‐4‐hydroxyphenylacrilonitrile mixture. This mixture was unambiguously characterized by MS and ¹H‐NMR spectroscopy, and its sublimation capability was demonstrated. These results explain the well‐known cluster formation, fading (vanishing) and further recovering of CHC when used as a matrix in UV‐MALDI‐MS. Commercial SA (SA 98%; trans‐SA/cis‐SA 5 : 1) showed mainly cis‐ to‐trans thermal isomerization and, with very poor yield, loss of CO₂, yielding (3′,5′‐dimethoxy‐4′‐hydroxyphenyl)‐1‐ethene as the decarboxilated product. These thermal conversions would not drastically affect its behavior as a UV‐MALDI matrix as happens in the case of CHC. Complementary studies of the photochemical stability of these matrices in solid state were also conducted. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis of benzo[b][1,4]thiazepines by the reaction of 3‐aryl‐1‐(3‐coumarinyl)propen‐1‐ones with 2‐aminothiophenol

3‐(2‐Aryl‐2,3‐dihydro‐benzo[b][1,4]thiazepin‐4‐yl)chromen‐2‐ones ( 2a, e, f ) and (Z)‐3‐(2,3‐dihydro‐2‐arylbenzo[b][1,4]thiazepin‐4(5H)‐ylidene)chroman‐2‐ones ( 3a‐f ) have been synthesized by the reaction of 3‐aryl‐1‐(3‐coumarinyl)propen‐1‐ones ( 1a‐f ) with 2‐aminothiophenol in a hot mixture of toluene and acetic acid. Structures of all new compounds and their complete ¹H and ¹³C assignments were achieved applying different one‐ and two‐dimensional nmr experiments in combination with various spectroscopic techniques.