Photoinduced perfluorobutylation of organic substrates in aqueous media

Hydroperfluorobutylation of a series of electron-deficient and electron-rich alkenes through consecutive radical reactions employing perfluorobutyl iodide, n-C4F9I, and (Me3Si)3SiH as chain carrier/hydrogen atom donor is described. The photoinduced Halogen Atom Transfer (HAT) reactions of both olefins and alkynes with n-C4F9I are also shown to be achieved efficiently in aqueous mixtures. On the other hand, aromatic and heteroaromatic substrates can be perfluorobutylated with high efficiency in a photoinduced fashion by means of a Homolytic Aromatic Substitution (SHA) process which involves an Electron Transfer (ET) and a Proton Transfer (PT) step.Fil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Aromatic radical perfluoroalkylation reactions

This account intends to cover recent literature on radical perfluoroalkylation reactions of aromatic nuclei in organic and aqueous media. Emphasis will be placed on radical aromatic perfluoroalkylation reactions in water or aqueous media, with the aim of exploring aromatic radical reactivity in a benign environment. © 2012 Published by NRC Research Press.Fil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A novel type of nucleophilic substitution reactions on nonactivated aromatic compounds and benzene itself with trimethylsiliconide anions

Matrix presented The reaction of fluorobenzene with Me3Si- anion (1) in HMPA at room temperature surprisingly affords o- and p-fluorotrimethylsilylbenzenes (substitution of aromatic H for TMS, 76% yield) 7a and 7b and also 14% of trimethylsilylbenzene (2). Benzene itself reacts at 50°C to furnish 4 in 45% yield. Pyridine affords p-trimethylsilylpyridine quantitatively. Mechanistic studies are presented.Fil: Postigo, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Rossi, Roberto Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Photocatalytic Difluoromethylation Reactions of Aromatic Compounds and Aliphatic Multiple C-C Bonds

Among the realm of visible light photocatalytic transformations, late-stagedifluoromethylation reactions (introduction of difluoromethyl groups in the last stages of syntheticprotocols) have played relevant roles as the CF2X group substitutions exert positive impacts on thephysical properties of organic compounds including solubility, metabolic stability, andlipophilicity, which are tenets of considerable importance in pharmaceutical, agrochemical, andmaterials science. Visible-light-photocatalyzed difluoromethylation reactions are shown to beaccomplished on (hetero)aromatic and carbon?carbon unsaturated aliphatic substrates under mildand environmentally benign conditions.Fil: Barata Vallejo, Sebastian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Photocatalytic fluoroalkylation reactions of organic compounds

Photocatalytic methods for fluoroalkyl-radical generation provide more convenient alternatives to the classical perfluoroalkyl-radical (Rf) production through chemical initiators, such as azo or peroxide compounds or the employment of transition metals through a thermal electron transfer (ET) initiation process. The mild photocatalytic reaction conditions tolerate a variety of functional groups and, thus, are handy to the late-stage modification of bioactive molecules. Transition metal-photocatalytic reactions for Rf radical generation profit from the redox properties of coordinatively saturated Ru or Ir organocomplexes to act as both electron donor and reductive species, thus allowing for the utilization of electron accepting and donating fluoroalkylating agents for Rf radical production. On the other hand, laboratory-available and inexpensive photoorgano catalysts (POC), in the absence of transition metals, can also act as electron exchange species upon excitation, resulting in ET reactions that produce Rf radicals. In this work, a critical account of transition metal and transition metal-free Rf radical production will be described with photoorgano catalysts, studying classical examples and the most recent investigations in the field.Fil: Barata Vallejo, Sebastian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonesi, Sergio Mauricio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Fluorination methods in drug discovery

Fluorination reactions of medicinal and biologically-active compounds will be discussed. Late stage fluorination strategies of medicinal targets have recently attracted considerable attention on account of the influence that the fluorine atom can impart to targets of medicinal importance, such as a modulation of lipophilicity, electronegativity, basicity and bioavailability, this latter as a consequence of membrane permeability. Therefore, the recourse to late-stage fluorine substitution on compounds with already known and relevant biological activity can provide the pharmaceutical industry with new leads with improved medicinal properties. The fluorination strategies will take into account different fluorinating reagents, nucleophilic, electrophilic and of radical nature. Diverse families of organic compounds such as (hetero)aromatic rings, and aliphatic substrates (sp3 , sp 2 , and sp carbon atoms) will be studied in late-stage fluorination reaction strategies.Fil: Yerien, Damián Emilio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonesi, Sergio Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Bioinspired Photocatalyzed Organic Synthetic Transformations. The Use of Natural Pigments and Vitamins in Photocatalysis

Due to the necessity for more environmentally benign processes in synthetic organic chemistry, and in particular in photocatalysis, a recourse to photocatalysts that are also found in nature and mimic natural processes to accomplish organic transformations is very appealing. Synthetic useful reactions such as oxidations, reductions, carbon-oxygen, carbon-carbon and carbon-sulfur bond formation reactions, and E-to-Z geometrical isomerization reactions photocatalyzed by biological natural pigments, vitamins, cofactors, and compounds with antiviral activity will be discussed in this account. Interestingly, due to the remarkable redox properties and triplet energies of some of these catalysts that are found in nature, both electron transfer (ET)- and energy transfer (EnT)-driven photocatalytic processes can be accomplished.Fil: Barata Vallejo, Sebastian. Consiglio Nazionale delle Ricerche; Italia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Yerien, Damián Emilio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Synthetic strategies for fluorosulfonylated compounds: application to click chemistry reactions

The syntheses and applications of fluorosulfonylated organic compounds have flourished in the last ten years due to their versatility to participate in click chemistry (SuFEx) reactions. Also, organic architectures that combine the SO2F group and other ancillary functional moieties such as olefins, alkynes, etc. (i.e.: bis-electrophiles) have augmented the applications and diversity of the end compounds. To this effect, the association of an alkyne functionality and the SuFExable group within one structure has been shown to encompass two-in-one click chemistry sequential protocols with the aim of building on the diversity of scaffolds by two consecutive click processes. We next examine the syntheses of (hetero)aromatic-, alkyl-, alkenyl-, and alkynyl-sulfonyl fluorides and β-keto-sulfonyl fluorides and the syntheses of compounds bearing N-SO2F and O-SO2F bonds through diverse catalytic methods, illustrating examples of their SuFEx click chemistry and other ancillary functional group reactivity.Fil: Barata Vallejo, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; Argentina. Consiglio Nazionale delle Ricerche. Istituto per la Sintesi Organica e la Fotoreattività; ItaliaFil: Yerien, Damián Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; ArgentinaFil: Postigo, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica. Cátedra de Química Orgánica I; Argentin

Photocatalyzed reductive fluoroalkylation of 2-acetoxyglycals towards the stereoselective synthesis of α-1-fluoroalkyl-: C -glycosyl derivatives

A benign, efficient, regio- and stereoselective protocol for the syntheses of α-1-fluoroalkyl-C-glycosyl compounds bearing CF3, C4F9, and C6F13 substituents on the anomeric carbon has been developed by a new methodology starting from 2-acetoxyglycals for the first time. Remarkably, the reactions proceeded in only one step, through the visible light-photocatalyzed reductive fluoroalkylation of 2-acetoxyglycals by means of an Ir photocatalyst and employed commercially available fluoroalkyl iodides n-CnF2n+1-I (n = 1, 4, 6) as a source of fluoroalkyl radicals.Fil: Mora Flores, Erwin Wilfredo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Uhrig, Maria Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Postigo, Jose Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Catalytic Fluoroalkylation Reactions of Alcoxy‐subtituted (Hetero)Arenes

Electron-rich alcoxy-substituted (hetero)arenes and electrophilic fluoroalkyl moieties represent advantageous partners for substitution reactions due to their electronic match. Fluoroalkylation strategies of alcoxy-substituted (hetero)arenes are herein presented which depict photocatalytic and thermal methods. Photocatalytic methods rely on the use of diverse photocatalysts such as Ru(bpy)3Cl2, tetrabutylammonium decatungstate TBADT, N-doped carbon nanodots NCNDs, and vitamin derivatives which can partner with the Langlois reagent NaSO2CF3, CF3CO2H, and perfluoroalkyl iodides RFI as fluoroalkylating reagents. Also, electrocatalytic methods that make use of the cathodic reduction of CF3SO2Cl to generate CF3 radicals can achieve trifluoromethylation reactions of alcoxysubstituted (hetero)arenes. On the other hand, thermal methodologies comprising Pd(OAc)2 catalysis and using CF3Br as trifluoromethylating source have been implemented.Fil: Yerien, Damián Emilio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lantaño, Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Barata Vallejo, Sebastian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consiglio Nazionale delle Ricerche; ItaliaFil: Postigo, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin