3,468 research outputs found
Ketosulfonyl indoles in the regiodefined synthesis of tryptophols and related indole derivatives
No full textReduction of ketosulfonyl indoles with sodium borohydride provides a ready entry to tryptophols in a regiocomplementary fashion with respect to the traditional oxirane ring-opening by indoles under Friedel–Crafts conditions. Compared to traditional β-ketosulfones, ketosulfonyl indoles show a peculiar behavior since they undergo a Lewis acid promoted elimination of the arylsulfonyl group allowing the preparation of indolyl-substituted 1,4-dicarbonyl derivatives
A Simplified Synthesis of 3-(1-Arylsulfonylalkyl) Indoles and their Reaction with Reformatsky Reagents
No full textA simple procedure for the preparation of 3-(1-arylsulfonyl-alkyl) indoles by three-component condensation of indoles, carbonyls, and arenesulfinic acids is presented. The obtained products undergo a Reformatsky reaction leading to alkyl 3-(3-indolyl) alkanoates and (3-indolyl) ketones
A imagem de Alessandro Baricco no Brasil
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Estudos da Tradução, Florianópolis, 2013.Com a intenção de delinear o modo pelo qual o escritor italiano Alessandro Baricco se inseriu no sistema literário brasileiro e os caminhos percorridos pelos seus livros traduzidos, esta dissertação dá voz às experiências tradutórias de seus tradutores. A inserção de Bariccono Brasil tem seu início em 1997, através de uma proposição da Profa. Dra. Roberta Barni à editora Iluminuras da tradução de Oceano Mare. A partir daí, outras sete obras foram publicadas no Brasil, sendo três delas traduzidas por Roberta Barni e as outras quatro por quatro tradutores diferentes. De um lado, considera-se o tradutor como figura principal namediação entre culturas, e, de outro, se analisa a realidade desta figuradentro do sistema literário, sua invisibilidade, seus limites e o exercíciode sua profissão. A pesquisa conta, ainda, com críticas e resenhas referentes ao autor italiano publicadas em jornais consagrados no Brasil, considerando estas como parte constituinte da imagem de Baricco refletida em território nacional. Abstract : Intending to delineate the way the Italian writer Alessandro Baricco has been inserted in the Brazilian literary system and the paths his translated books have followed, this thesis gives voice to the translating experiences of his translators. Baricco's insertion in Brazil began in 1997, through a personal project of Dr. Roberta Barni, with her translation of Oceano Mare. Since then, seven other of his works have been published in Brazil, three of which were translated by Roberta Barni and the other four by four different translators. On the one hand,the translator is considered as the main figure in mediation betweencultures and, on the other, this figure's reality is analyzed within theliterary system: its invisibility, its limits and its professional practice. Criticisms and reviews of this Italian author published in well established Brazilian newspapers are also considered, with the understanding that they are part of Baricco's image reflected here
Recent Advances in the Synthesis of Unsymmetrical Bisindolylmethane Derivatives
No full textThis review article summarizes the fundamental synthetic
procedures aimed at the preparation of unsymmetrical bisindolylmethanes
that have appeared in the literature since 2010. To this goal, reactive
electrophilic indole-containing intermediates are mostly generated
from indolylmethanols, indolylmethanamines, and indolylmethanthio
derivatives and then made to react with simple or functionalized indoles.
The asymmetric synthesis of bisindolylmethanes can be also
achieved under chiral-catalyzed conditions
Sulfonyl Azoles in the Synthesis of 3-Functionalized Azole Derivatives
No full textSulfonyl indoles, as well as related azolyl derivatives, have been recently introduced in synthesis as stable precursors of reactive indolenine intermediates. This personal account reports on the discovery of sulfonyl azoles and their practical utilization in many synthetic processes for the preparation of functionalized 3-substituted indoles, indazoles, and pyrroles. The indolenine intermediates obtained by treatment of sulfonyl azoles with Brønsted bases or Lewis acids can be considered as vinylogous imino derivatives that can be made to react with different nucleophilic reagents. These include organometallic reagents, reducing agents, stabilized carbanions, and heteronucleophiles. The controlled and mild conditions for the generation of indolenines from sulfonyl azoles make these substrates particularly useful in asymmetric synthesis, exploiting organo- or metal-catalyzed processes. Although less exploited, sulfonyl indoles can also be involved in photochemical processes for the preparation of polycyclic derivatives
Denitrative radical-induced coupling reactions of nitroalkenes
No full textThe classical reactivity of nitroalkenes, involving regioselective 1,4-addition by nucleophilic reagents, can
be modified in β-nitrostyrenes using free radical species, which selectively add to nitro-bearing unsaturated
carbon. The resulting stabilized benzylic radical undergoes a denitrative process leading to the formation
of substituted alkenes. Alkyl and aryl radicals can be employed in this process, which can also be
extended to the use of sulfur- and phosphorus-centered radicals. These radical species can be generated
using oxidative, reductive or photocatalyzed procedures, which also ensure notable diastereoselectivity in
alkene formation. Although currently applied only to β-nitrostyrenes, this approach could potentially be
extended to any nitroalkene bearing a radical-stabilizing group at the beta position
Tryptophol and derivatives: natural occurrence and applications to the synthesis of bioactive compounds
No full textTryptophol (indole-3-ethanol) is a metabolite produced by plants, bacteria, fungi and sponges. This review reports on the natural occurrence, bioactivity and various synthetic approaches to the preparation of tryptophol and its derivatives. Syntheses of various naturally occurring tryptophol derivatives known for their enhanced pharmacological profile are also presented
2-Aminoindoles and 2-Iminoindolines as Viable Precursors of Indole-Fused Nitrogenated Polyheterocycles
No full textThe synthesis of architecturally complex
polyheterocyclic structures embedding the indole ring
represents a growing field of interest. Carbolines and
their partially dehydro derivatives, pyrazinoindoles,
indoloindoles, azepinoindoles and other mediumsized
derivatives are only some examples of indolecontaining
polycyclic compounds featured by enhanced
pharmacological and photophysical properties.
Among various synthetic protocols to prepare
these important target compounds those based on the
utilization of 2-aminoindoles and 2-iminoindolines
are gaining increasing interest because of the ease of
their preparation. The presence of a couple of reactive
sites in these derivatives is instrumental for the
assembling of polyheterocyclic structures exploiting
single step operations featured by efficient cascade or
tandem processes. Several of these methods employ
catalyzed reactions which can be developed for the
asymmetric synthesis of enantiopure compounds.
This review provides an up-to-date report on the
currently available methods for the synthesis of 2-
aminoindoles and 2-iminoindolines and their application
to the preparation of polyheterocyclic derivatives
La maturità di Alessandro Fei del Barbiere, in bilico tra Maniera e Riforma
No full textThis article studies the mature career of the Florentine painter Alessandro Fei del Barbiere (1537-1592), beginning with the rediscovery of the 'Ascension' altarpiece formerly in the Albizi Chapel in the destroyed church of San Pier Maggiore, Florence. Studying this painting and others recorded in 1584 by the biographer Raffaello Borghini, such as the two altarpieces for Santa Maria delle Grazie and the Madonna dell'Umiltà in Pistoia, the author reconstructs a body of works showing how in the 1580s Fei gradually went beyond the archaic style of his apprenticeship - he had been trained by Ridolfo del Ghirlandaio and Pierfrancesco Foschi, but was also marked by the Maniera of Vasari - evolving towards naturalism in both mimesis and pictorial handling. In Florence, his development partly parallels that of Santi di Tito and his circle, but Fei was also influenced by a probable sojourn during the early part of that decade in Rome, where he could have been inspired by Girolamo Muziano and the painters working for Pope Gregory XIII. Among other proposals, the author suggests that the artist was responsible for decorating the chancel of Fiesole Cathedral (c. 1584-1589), which consisted of an altarpiece, only rarely discussed by scholars, and a cycle of frescoes hitherto attributed to Nicodemo Ferrucci
Arylsulfonyl Group: Activating Properties and Recent Synthetic Applications
No full textThe carbanion stabilizing effect induced by the arylsulfonyl group has dominated and typified the chemistry of this functional entity for a long time. In addition to this important feature, the activity of the arylsulfonyl moiety as a leaving group has been exploited and a plethora of exciting synthetic applications have been found. The base-or acid-promoted elimination of the sulfonyl group from of alpha-amido sulfones and sulfonyl indoles is able to produce the in situ generation of reactive N-acylimino and alkylideneindolenine intermediates that can be used in the diastereo and enantioselective synthesis of various amino and heterocyclic compounds
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