Magnesium Monoperoxyphthalate Research Articles

Destruction of chemical warfare agents VX and soman by α‐nucleophiles as oxidizing agents

AbstractReactions of O‐ethyl S‐(2‐diisopropyl‐amino)ethyl methylphosphonothiolate, VX 1, were investigated with five oxidizing agents. In all the cases, the formation of the VX N‐oxide 7 was observed prior to the subsequent oxidation and hydrolysis into the nontoxic O‐ethyl methylphosphonate 2. Magnesium monoperoxyphthalate (MMPP) is probably one of the most active reagents to achieve the complete detoxification of VX 1. The decontamination using MMPP was also extended with success to soman 13, a G‐type agent. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:485–490, 2001

Enantioselective Synthesis of 4-Unsubstituted 3-Alkoxy- and 3-Aminoazetidin-2-ones from Formaldehyde N,N-Dialkylhydrazones

Playing two roles at once, chiral amines from L-proline or D-mannitol act as protecting groups and as chiral auxiliaries in the [2+2] cycloaddition of formaldehyde hydrazones, such as 1, to ketenes. This strategy, based on the stability of the hydrazones as methanimines and on the development of a new oxidative cleavage of hydrazides, provides a short entry to enantiopure 4-unsubstituted 3-alkoxy- and 3-aminoazetidinones with desired configurations. X=OBn, N(CO2Bn)Bn; Bn=benzyl; MMPP=magnesium monoperoxyphthalate.

Introduction of thiol-reactive structures on to soluble and insoluble proteins.

When proteins containing disulphide groups were oxidized with magnesium monoperoxyphthalate at acidic pH, they acquired the property of binding thiol compounds. This was the case with the insoluble protein keratin, chosen for having a large number of disulphide bridges, and with soluble ones like BSA and immunoglobulins. The potential applications of some of these modified proteins for the preparation of soluble bioconjugates have been explored. As a particular example of an application, the immobilization of activated IgG on to solid phases might provide a new way for preparing immunoadsorbents.

Synthesis of Halfsandwich Ruthenium Complexes of Sulfinic Acid Esters [1

A series of halfsandwich ruthenium sulfinato complexes [CpRu(PR'3)2(SO2R)] (R = Me, CH2Ph, C2H4Ph, Ph, 4-C6H4Me; PR'3 = PMe3, 1/2 dppm) with various electronic and steric environments around the ruthenium centre, have been prepared by insertion of SO2 into a ruthenium carbon bond, by a direct ligand exchange reaction, or by oxidation of thiolato complexes with 3-chloroperoxybenzoic acid. The chiral complexes [CpRu(CO )(PPh3)(SO2R)] (R = Me, CH2Ph, Ph) were obtained similarly by oxidation of the corresponding thiolates with magnesium monoperoxyphthalate. Alkylation of the sulfinato complexes with oxonium salts [R"3O]X (R" = Me, Et; X = BF4 , PF6) gave ruthenium complexes of sulfinic acid esters, [CpRu(L)(L′)(S(O)(OR″)R)]X in high yields and, for the chiral complexes, up to 82% de. The esters may be detached from the metal by ligand exchange with acetonitrile. Stronger nucleophiles such as I- or SMe- dealkylate the coordinated sulfinic acid esters.

Pernitrated metalloporphyrins as catalysts in oxidation with magnesium monoperoxophthalate: I. Epoxidation of cyclic olefins

Metalloporphyrins with several nitro groups in β-positions were used in the epoxidation of cyclic olefins with magnesium monoperoxyphthalate (MMPP) as an oxygen atom donor, under mild conditions. Iron- and manganese-pernitrated complexes are able to promote the epoxidation of alkenes without requiring the addition of any nitrogen base. Cobalt porphyrins showed low activity, but addition of the cocatalyst raised it.

Surface-Mediated Reactions. 7. Unsupported Reagents1

Some solid reagents traditionally supported on silica gel or alumina are also effective as heterogeneous reactants in the absence of a support. Moist magnesium monoperoxyphthalate (MMPP), either suspended in CH2Cl2 or solventless, is a convenient alternative to peroxycarboxylic acids for oxidation of sulfides and epoxidation of alkenes. The latter reaction exhibits an unusual order of reactivity: trisubstituted > disubstituted > tetrasubstituted. Unsupported moist Ca(OCl)2 and OXONE are also effective oxidants.

Asymmetric synthesis of γ-cyano silyl enol ethers

The selective oxidative cleavage of the SAMP-hydrazone moiety of 4-silyloxy-3-enal hydrazones 6, leading to the corresponding 4-silyloxy-3-alkenenitriles 7, is reported. A clean, good yielding transformation was observed when m-CPBA in CH 2Cl 2 was used as the oxidant, the presence of suspended solid NaHCO 3 being essential in preventing hydrolysis of the silyl enol ether moiety. Use of magnesium monoperoxyphthalate (MMPP) led to over-oxidated products, while hydrogen peroxide, in the presence of catalytic methyltrioxorhenium (MTO), was ineffective. Independent measurements of the enantiomeric excesses for compounds 7 demonstrated the absence of racemization during the process.

ChemInform Abstract: Chemoselective Oxidation of Sulfides to Sulfones with Magnesium Monoperoxyphthalate (MMPP) on Silica Gel Support in Methylene Chloride Solvent.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Chemoselective Oxidation of Sulfides to Sulfones with Magnesium Monoperoxyphthalate (MMPP) On Silica Gel Support in Methylene Chloride Solvent

A simple, efficient and chemoselective, non-aqueous procedure for oxidation of sulfides to the corresponding sulfones with magnesium monoperoxyphthalate on hydrated silica gel has been developed.

Mechanism for benomyl action as a mitochondrial aldehyde dehydrogenase inhibitor in mice.

Benomyl (a non-thio fungicide) inhibits hepatic mitochondrial low-Km aldehyde dehydrogenase (mALDH or ALDH2) in ip-treated mice by 50% (IC50) at 7.0 mg/kg, which is surprisingly the same potency range as that for several dithiocarbamate fungicides (and the related alcohol abuse drug disulfiram) and thiocarbamate herbicides previously known for their alcohol-sensitizing action. The mechanism by which benomyl inhibits mALDH was therefore examined, first by comparing the metabolism of benomyl with the aforementioned mono- and dithiocarbamates and second by evaluating the inhibitory potency of the benomyl metabolites. Benomyl in ip-treated mice is converted, via butyl isocyanate, S-(N-butylcarbamoyl)glutathione, and S-(N-butylcarbamoyl)cysteine, to S-methyl N-butylthiocarbamate (MBT), identified as a transient metabolite in liver. MBT is >10-fold more potent than benomyl or butyl isocyanate as an in vivo mALDH inhibitor and is also more potent than the intermediary S-(N-butylcarbamoyl) conjugates. Benomyl and MBT inhibit mouse hepatic mALDH in vitro with IC50s of 0.77 and 8.7 microM, respectively. The potency of MBT is greatly enhanced by fortification of the mitochondria with NADPH alone or plus microsomes giving IC50s of 0.50 and 0.23 microM, respectively. This activation of MBT is almost completely blocked by the cytochrome P450 inhibitor N-benzylimidazole but not by several other cytochrome P450 inactivators. MBT (probably following bioactivation) inhibits mALDH in vivo with an IC50 of 0.3 mg/kg. Two candidate activation products were synthesized for potency determinations. N-Hydroxy MBT (prepared via the trimethylsilyl derivative) was not detected as an MBT metabolite; its low potency also rules against N-hydroxylation as the activation process. MBT sulfoxide, from oxidation of MBT with magnesium monoperoxyphthalate in water, is one of the most potent inhibitors known for mALDH and yeast ALDH in vitro (IC50 0.08-0.09 microM). These findings are consistent with a six-step bioactivation of benomyl, via the metabolites above and N-butylthiocarbamic acid, with MBT as the penultimate and MBT sulfoxide as the ultimate inhibitor of mALDH.

Ni(II)·Xaa-Xaa-His Induced DNA Cleavage: Deoxyribose Modification by a Common “Activated” Intermediate Derived from KHSO5, MMPP, or H2O2

Ni(II) chelated peptides of the form NH2-Xaa-Xaa-His-CONH2 (Ni(II)·Xaa-Xaa-His) mediate deoxyribose damage through C4‘−H abstraction of a targeted nucleotide when activated with KHSO5 (oxone), MMPP (magnesium monoperoxyphthalate), or H2O2. The products released and identified in comparison to the authentic C4‘−H oxidant Fe(II)·bleomycin included fragmented DNA terminating in 5‘-phosphates, 3‘-phosphates, and 3‘-phosphoglycolates; upon treatment of Ni(II)·Xaa-Xaa-His cleavage reactions with NaOH or NH2NH2, fragmented DNA 3‘-termini were released consistent with the intermediate formation of keto-aldehyde abasic (alkaline-labile) sites. In addition, nucleobases and nucleobase propenals were detected in proportions consistent with abasic site and 3‘-phosphoglycolate termini formation, respectively. These results indicate that Ni(II)·Xaa-Xaa-His metallopeptides, like Fe(II)·bleomycin, degrade DNA through two pathways resulting from an initial C4‘−H modification. Importantly, the partitioning between these two...

ChemInform Abstract: A Facile and Selective Procedure for Oxidation of Sulfides to Sulfoxides on Silica Gel Supported Magnesium Monoperoxyphthalate (MMPP) in Dichloromethane.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Facile and Selective Procedure for Oxidation of Sulfides to Sulfoxides on Silica Gel Supported Magnesium Monoperoxyphthalate (MMPP) in Dichloromethane

The scope of the magnesium monoperoxyphthalate (MMPP) oxidation of sulfides to sulfoxides has been extended by using hydrated silica gel as a solid support in dichloromethane media. This procedure works in the presence of a number of functional groups on the sulfides, including carbonyl and alkene groups that have been known to undergo Baeyer-Villiger oxidation and epoxidation with MMPP when using more conventional procedures. To our knowledge, this is the first example of oxidation of sulfides containing a carbonyl group with MMPP in non-aqueous media without any Baeyer-Villiger reaction. The reported procedure is easy to perform, product separation is trivial and it produces excellent yields.

Studies on ring opening reactions of β-lactams

Reaction of tricyclic azetidinones 1–5 (azetobenzoxazine, -thiazine, -thiazepine and -azepine derivatives) with trifluoroacetic acid led to bicyclic thioesters 6–13. There is evidence for an intermolecular reaction, a possible mechanism is discussed. The structure of two representative thioesters (8 and 9) was elucidated by different NMR experiments, complete assignments of 1H- and 13C-chemical shifts are given. Reaction of the azetobenzoxazine 2 with sodium periodate and magnesium monoperoxyphthalate led to the sulfoxide 18 and the sulfone 19, respectively.

Ultrasonically stimulated oxidation reactions of 2,5-disubstituted C 18 furanoid fatty ester

Oxidative ring opening reaction of methyl 9,12-epoxy-9,11-octadecadienoate ( 1) with excess magnesium monoperoxyphthalate (MMPP) under ultrasonic irradiation in water furnished methyl 9,12-dioxo- cis-10-octadecenoate ( 2, 93%). Reaction of compound 1 with 10 molar equivalents of m-chloroperoxybenzoic acid ( m-CPBA) in dichloromethane gave methyl cis-10,11-epoxy-9,12-dioxooctadecanoate ( 3, 91.5%) exclusively. Under ultrasonic irradiation, compound 1 reacted with m-CPBA to give a mixture of compounds 2 (60%) and 3 (40%). Isomerization of methyl 9,12-dioxo- cis-10-octadecenoate ( 2) to the corresponding trans-isomer (methyl 9,12-dioxo- trans-10-octadecenoate, 4, 95%) was achieved in the presence of pyridine in water under ultrasonic irradiation. Compound 4, alternatively prepared in 95% yield from compound 1 by reaction with pyridinium chlorochromate, was readily epoxidized with hydrogen peroxide to methyl trans-10,11-epoxy-9,12-dioxooctadecanoate ( 5, 95%). The corresponding cis-isomer (methyl 9,12-dioxo- cis-10-octadecenoate, 2) resisted all attempts by MMPP and hydrogen peroxide to be epoxidized. The structures of the various derivatives ( 2– 5) of compound 1 were identified by a combination of spectroscopic techniques including IR, 1H- and 13C-NMR spectroscopy.

MMPP(Magnesium Monoperoxyphthalate) in Acetonitrile; A New Approach to the Synthesis of LactonesviaBaeyer-Villiger Oxidation of Cyclic Ketones

Abstract A variety of unsubstituted and mono- or di-substituted cycloalkanones can be oxidised with modest excess of magnesium monoperoxyphthalate hexahydrate in acetonitrile to produce the corresponding lactones in a facile, selective, and high yielding manner.

Reactivity of polyhalogenated metalloporphyrins in epoxidation of propene with magnesium monoperoxyphthalate

Epoxidation of propene with magnesium monoperoxyphthalate used as oxidant and manganese as well as iron polyhalogenated porphyrins as catalysts has been investigated under mild conditions. The systems with manganese tetra- ortho-dichlorophenyl- and tetrapentafluorophenylporphyrin appeared very effective and high turnover numbers and selectivities were observed. Porphyrin complexes in which halogen atoms were present in both the phenyl and pyrrole rings showed lower catalytic activity than the complexes with ligands carrying halogen substituents only on the phenyl rings.

Metal-ion-dependent oxidative DNA cleavage by transition metal complexes of a new water-soluble salen derivative

A new water-soluble, salen [salen = bis(salicylidene) ethylenediamine]-based ligand, 3 was developed. Two of the metal complexes of this ligand, i.e., 3a, [Mn(III)] and 3b, [Ni(II)], in the presence of cooxidant magnesium monoperoxyphthalate (MMPP) cleaved plasmid DNA pTZ19R efficiently and rapidly at a concentration ≈ 1 μM. In contrast, under comparable conditions, other metal complexes 3c, [Cu(II)] or 3d, [Cr(III)] could not induce any significant DNA nicking. The findings with Ni(II) complexes suggest that the DNA cleavage processes can be modulated by the disposition of charges around the ligand.

NOUVEAUX DECONTAMINANTS. DESTRUCTION RAPIDE, TOTALE ET DOUCE DU DIAZINON, UN PHOSPHOROTHIOATE INSECTICIDE PAR LE MONOPERPHTALATE DE MAGNESIUM (MPPM)

Abstract Magnesium monoperoxyphthalate (MMPP) reacts rapidly with diazinon [(0,0-diethyl-0-(2-isopropyl-4-methyl-6-pyrimidyl)phosphorothioate] under mild conditions leading 2-isopropyl-6-methylpyrimidol as well as 0,0-diethylphosphorothioic and phosphoric acids.

ChemInform Abstract: Some Observations on Baeyer‐Villiger Oxidation of Alicyclic Ketones with Magnesium Monoperoxyphthalate in Aprotic Solvent in the Presence of Bentonite Clay.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.