- Palladium(0)-Catalyzed Substitution of Allylic Substrates in an Aqueous-Organic Medium
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A palladium(0)-water soluble catalyst prepared in situ from palladium acetate and the sulfonated triphenyl phosphine P(C6H4-m-SO3Na)3 (or tppts) is an efficient catalyst for allylic substitution with various carbon and heteronucleophiles in an aqueous-organic medium, allowing a very easy separation of the product(s) and the recycling of the catalyst.
- Blart, Errol,Genet, Jean Pierre,Safi, Mohamed,Savignac, Monique,Sinou, Denis
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- Sustainable Manganese-Catalyzed Solvent-Free Synthesis of Pyrroles from 1,4-Diols and Primary Amines
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A general and selective metal-catalyzed conversion of biomass-derived primary diols and amines to the highly valuable 2,5-unsubstituted pyrroles has been developed. The reaction is catalyzed by a stable nonprecious manganese complex (1 mol %) in the absence of organic solvents whereby water and molecular hydrogen are the only side products. The manganese catalyst shows unprecedented selectivity, avoiding the formation of pyrrolidines, cyclic imides, and lactones.
- Borghs, Jannik C.,Lebedev, Yury,Rueping, Magnus,El-Sepelgy, Osama
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supporting information
p. 70 - 74
(2019/01/11)
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- Nickel-Catalyzed Synthesis of N-Substituted Pyrroles Using Diols with Aryl- and Alkylamines
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Herein, nickel-catalyzed sustainable strategy for the synthesis of N-substituted pyrroles using butene-1,4-diols and butyne-1,4-diols with a series of aryl-, alkyl-, and heteroarylamines is reported. The catalytic protocol is tolerant of free alcohol, halide, alkyl, alkoxy, oxygen heterocycles, activated benzyl, and the pyridine moiety and resulted in up to 90% yield. Initial mechanistic studies involving defined nickel catalyst, determination of rate, and order of reaction including deuterium-labeling experiments were performed for pyrrole synthesis.
- Singh, Khushboo,Kabadwal, Lalit Mohan,Bera, Sourajit,Alanthadka, Anitha,Banerjee, Debasis
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p. 15406 - 15414
(2019/01/04)
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- Unveiling the Biocatalytic Aromatizing Activity of Monoamine Oxidases MAO-N and 6-HDNO: Development of Chemoenzymatic Cascades for the Synthesis of Pyrroles
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A chemoenzymatic cascade process for the sustainable production of pyrroles has been developed. Pyrroles were synthesized by exploiting the previously unexplored aromatizing activity of monoamine oxidase enzymes (MAO-N and 6-HDNO). MAO-N/6-HDNO whole cell biocatalysts are able to convert 3-pyrrolines into pyrroles under mild conditions and in high yields. Moreover, MAO-N can work in combination with the ruthenium Grubbs catalyst, leading to the synthesis of pyrroles from diallylamines/-anilines in a one-pot cascade metathesis-aromatization sequence.
- Scalacci, Nicoló,Black, Gary W.,Mattedi, Giulio,Brown, Nicola L.,Turner, Nicholas J.,Castagnolo, Daniele
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p. 1295 - 1300
(2017/08/09)
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- Model studies on the degradation of phenylalanine initiated by lipid hydroperoxides and their secondary and tertiary oxidation products
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The reaction of methyl 13-hydroperoxyoctadeca-9,11-dienoate (MeLOOH), methyl 13-hydroperoxyoctadeca-9,11,15-trienoate (MeLnOOH), methyl 13-hydroxyoctadeca-9,11-dienoate (MeLOH), methyl 13-oxooctadeca-9,11-dienoate (MeLCO), methyl 9,10-epoxy-13-hydroxy-11-octadecenoate (Me-LEPOH), and methyl 9,10-epoxy-13-oxo-11-octadecenoate (MeLEPCO) with phenylalanine was studied to determine the comparative reactivity of primary, secondary, and tertiary lipid oxidation products in the Strecker degradation of amino acids. All assayed lipids were able to degrade the amino acid to a high extent, although the lipid reactivity decreased slightly in the following order: MeLEPCO ≥ MeLCO > MeLEPOH ≥ MeLOH > MeLOOH ≈ MeLnOOH. These data confirmed the ability of many lipid oxidation products to degrade amino acids by a Strecker-type mechanism and suggested that, once the lipid oxidation is produced, a significant Strecker degradation of surrounding amino acids should be expected. The contribution of different competitive mechanisms to this degradation is proposed, among which the conversion of the different lipid oxidation products assayed into the most reactive MeLEPCO and the fractionation of long-chain primary and secondary lipid oxidation products into short-chain aldehydes are likely to play a major role.
- Zamora, Rosario,Gallardo, Emerenciana,Hidalgo, Francisco J.
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experimental part
p. 7970 - 7975
(2010/03/30)
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