0000000000335882
AUTHOR
Pau Arroyo
showing 10 related works from this author
Polymer-supported molybdenyl thioglycolate as oxygen atom transfer reagent
2000
Abstract Oxo-transfer reactions of a variety of substrates in DMF or methanol using polymer-supported molybdenyl thioglycolate (PSMT) have been investigated. The clean oxidation of Me 2 PhP, n -butanethiol or benzoin to yield Me 2 PhPO, disulfide or benzil, respectively, occurs in high yield. In the presence of air or pyridine N-oxide, a catalytic cycle is accomplished which goes on until the completion of the substrate.
Colorimetric and fluorescent hydrazone-BODIPY probes for the detection of γ-hydroxybutyric acid (GHB) and cathinones
2022
Consumption and abuse of drugs is a general problem, which concerns our entire society. In some cases, drugs are used for recreational purposes; but in others, they are used to commit crimes such as Drug-Facilitated Sexual Assault (DFSA). In other cases, this consumption alters the consumer mood in such a way that risky situations can rise. In any case, detection of drugs in different environment is worthwhile. Here, two new chromogenic and fluorescent probes are reported. Detection of both cathinone derivatives and γ-hydroxybutyric acid (GHB) can be carried out with naked-eye with limits of detection of 0.4 μM and 0.3 μM for GHB and 2.0 μM for ephedrone. Selectivity in the presence of othe…
A DFT study of the polar Diels–Alder reaction between 4-aza-6-nitrobenzofuroxan and cyclopentadiene
2005
Abstract The polar Diels–Alder reaction between 4-aza-6-nitrobenzofuroxan (ANBF) and cyclopentadiene has been studied using DFT procedures at the B3LYP/6-31G* level. Only one highly asynchronous transition state structure associated to the formation of the [4+2] adduct 13 is found. A further [3,3] sigmatropic shift on the [4+2] cycloadduct 13 allows its conversion into the thermodynamically more stable [2+4] cycloadduct 14 . The analysis of the global and local electrophilicities of the reagents correctly explain the behaviour of ANBF as a strong electrophile in polar cycloadditions.
Towards an Understanding of the Polar Diels–Alder Reactions of Nitrosoalkenes with Enamines: A Theoretical Study
2006
The polar Diels–Alder reactions of nitrosoalkenes with enamines have been studied using DFT methods at the B3LYP/6-31G* level of theory. These Diels–Alder reactions are characterized by a nucleophilic attack of the enamine at the conjugated position of the nitrosoalkene with concomitant ring-closure. The reactions present a total regioselectivity and a large endo selectivity. The analysis, based on the global electrophilicity of the reagents in the ground state, the natural bond orbital (NBO), and the topological analysis of the electron localization function (ELF) in the endo transition state (TS) and “halfway” along the IRC between the TS and cycloadduct, correctly explain the polar natur…
The domino reaction between 4,6-dinitrobenzofuroxan and cyclopentadiene. Insights on the nature of the molecular mechanism
2004
Abstract The molecular mechanism of the domino reaction between 4,6-dinitrobenzofuroxan, 1 , and cyclopentadiene, Cp, to give the adduct 11 is examined through density functional theory (DFT) calculations at B3LYP/6-31G* level. This domino reaction comprises two consecutive formally [4+2] cycloadditions. The first one is a two-center addition initialized by the nucleophilic attack of Cp to the more electrophilic center of 1 . The subsequent cyclization can take place along two competitive channels associated to the formation of a second C–C bond yielding the formally [2+4] cycloadduct 9 , or a C–O bond yielding the formally [4+2] cycloadduct 10 . The second cycloaddition is a stepwise proce…
Experimental and theoretical investigations for the regio and stereoselective transformation of trans 1,2,3-trisubstituted aziridines into trans oxaz…
2003
The regio and stereoselective transformation of trans 1,2,3-trisubstituted aziridines into trans oxazolidin-2-ones takes place in good yield. However, the cis configuration at C2 and C3 in monocyclic aziridines is a limiting factor for this transformation. Ab initio calculations show that while the ring-opening process assisted by iodide is regioselective, the subsequent ring-closure is responsible for the retention of the configuration at the trans oxazolidin-2-ones. The larger energy found for the ring-closure process for the cis aziridines accounts for the non-formation of the cis oxazolidin-2-ones.
Density functional theory study of the Lewis acid-catalyzed Diels-Alder reaction of nitroalkenes with vinyl ethers using aluminum derivatives
2002
The inverse electron demand Diels–Alder reaction of nitroalkenes with vinyl ethers catalyzed by Lewis acids based on aluminum metal, AlMe3, Al(OMe)3 and AlCl3 was studied using density functional theory methods. A continuum model was selected to represent the effects of dichloromethane used as solvent. For this cycloaddition reaction two reactive channels corresponding to the endo and exo approach modes of the vinyl ether to the Lewis acid-coordinated nitroalkene were studied. Coordination of the aluminum metal to an oxygen atom of the nitroalkene increases the electrophilicity of the heterodiene, decreasing the activation energy of the cycloaddition. The substitution effect on the aluminum…
Protection against chemical submission: naked-eye detection of γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages
2020
Two new oxazole derivatives, able to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages, by color and fluorescence changes, are reported.
Novel examples of the N-methyl effect on cyclisations of N-Boc derivatives of amino alcohols. A theoretical study
2004
New examples of the N-methyl effect on the cyclisation of N-tert-butoxycarbonyl derivatives of amino alcohols are reported. Ab initio studies for the displacement step with formation of the five-membered heterocycle indicate that the increase of the nucleophile character of the carbonyl oxygen of the carbamate group with the N-methyl substitution is responsible for the acceleration of the cyclisation step.
Heteroditopic chemosensor to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages.
2021
Drug-Facilitated Sexual Assault (DFSA) is a problem of considerable dimensions on a global scale. Among the different compounds used in DFSA assaults, 4-hydroxybutyric acid (GHB) is one of the most elusive due to its physical and biological characteristics. Therefore, the development of real-time detection methods to detect GHB not only in drinks but also in urine is very important for personal and social security. Here, we report two new heteroditopic chemosensors capable of recognizing and detecting GHB in soft drinks, alcoholic beverages and synthetic urine. The compounds have two moieties: a trifluoroacetyl group and a thiourea, which are able to interact respectively with the hydroxyl …