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1.
J Org Chem ; 88(16): 12069-12073, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37498652

RESUMO

A Rauhut-Currier reaction cascade is achieved in the presence of carbon nucleophiles under mild conditions. This original atom-economical transformation enables an efficient one-pot synthesis of densely substituted carbocycles from readily accessible substrates. The key promoter role of the cesium cation in the cascade process was demonstrated.

2.
J Org Chem ; 81(5): 1850-7, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26858139

RESUMO

A straightforward palladium-catalyzed oxidative hydroxylation of azobenzenes is reported. The developed methodology tolerates various functional groups and allows the synthesis of diverse unsymmetrical azophenols under mild conditions in good to excellent yields. A complementary procedure was also investigated by in situ generation of PIFA. This study represents the first general method for the synthesis of o-hydroxyazobenzenes starting from simple azoarenes.

3.
Chemistry ; 21(44): 15544-7, 2015 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-26493877

RESUMO

An unexpected acid-mediated cascade reaction induced by conjugate addition of sulfinamides to dienediones has been developed. This highly efficient Rauhut-Currier reaction enables the rapid, high-yielding construction of sulfonated cyclopentanes with three contiguous stereogenic centers in a single operation starting from simple sulfinamides. This process constitutes the first example of sulfinamide-promoted cycloisomerization.

4.
J Org Chem ; 80(5): 2796-803, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25653084

RESUMO

A novel protocol for the synthesis of tetrasubstituted olefins through a biomimetic approach has been explored. Both mono- and diarylations were performed under ambient oxygen pressure, giving a range of highly hindered tetrasubstituted alkenes. For diarylation of disubstituted substrates, it was demonstrated that the second arylation is the rate-limiting step of the overall transformation.


Assuntos
Alcenos/síntese química , Biomimética/métodos , Oxigênio/química , Alcenos/química , Catálise , Ligação de Hidrogênio , Estrutura Molecular
5.
Chemistry ; 20(20): 5890-4, 2014 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-24623664

RESUMO

The synthesis of 3-aryl-2-cyclohexenones is a topic of current interest as they are not only privileged structures in bioactive molecules, but they are also relevant feedstocks for the synthesis of substituted phenols or anilines, which are ubiquitous structural elements both in drug design and medicinal chemistry. A simple and sustainable one-pot aerobic double dehydrogenative reaction under mild conditions for the introduction of arenes in the ß-position of cyclic ketones has been developed. Starting from the corresponding saturated ketone, this reaction sequence proceeds under relatively low Pd catalyst loading and involves catalytic amounts of electron-transfer mediators (ETMs) under ambient oxygen pressure.

6.
Chemistry ; 20(25): 7548-64, 2014 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-24862089

RESUMO

Enamides are stable enamine surrogates and provide key intermediates for the synthesis of small but complex nitrogen-containing compounds. Metal-catalyzed regioselective functionalization of enamides provides a rapid method to synthesize useful nitrogen containing heterocycles. This review discloses the recent progress made in the development of the C-H functionalization of enamides involving efficient and atom-economical routes. Syntheses of different heterocycles are classified based on the site reactivity of enamides and key mechanistic insights are given for each transformation.


Assuntos
Amidas/química , Catálise , Estrutura Molecular , Nitrogênio , Estereoisomerismo
7.
RSC Adv ; 14(7): 4623-4631, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38318627

RESUMO

A straightforward and general metal-free method has been developed to add sufinamide-derived sulfone units on Michael acceptors under mild conditions. This reaction enables the preparation of a large variety of original γ-ketosulfones, of which only a few synthetic methods have been reported. The mild reaction conditions used tolerate a wide diversity of functional groups and empower the implementation of a late-stage functionalisation strategy.

8.
Front Toxicol ; 4: 973680, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36211198

RESUMO

Quaternary ammonium compounds (QAC) are commonly used disinfectants, antiseptics, preservatives, and detergents due to their antibacterial property and represent the first used biocides before phenolic or nitrogen products. Their common structure consists of one or more quaternary ammonium bound with four lateral substituents. Their amphiphilic structure allows them to intercalate into microorganism surfaces which induces an unstable and porous membrane that explains their antimicrobial activity towards bacteria, fungi, and viruses. QAC are thus found in many areas, such as household products, medicines, hygiene products, cosmetics, agriculture, or industrial products but are also used in medical practice as disinfectants and antiseptics and in health care facilities where they are used for cleaning floors and walls. QAC exposure has already been involved in occupational asthma in healthcare workers or professional cleaners by many authors. They also have been suggested to play a role in contact dermatitis (CD) and urticaria in workers using cosmetics such as hairdressers or healthcare workers, inciting reglementary agencies to make recommendations regarding those products. However, distinguishing the irritant or sensitizing properties of chemicals is complex and as a result, the sensitizing property of QAC is still controverted. Moreover, the precise mechanisms underlying the possible sensitization effect are still under investigation, and to date, only a few studies have documented an immunological mechanism. Besides, QAC have been suggested to be responsible for neuromuscular blocking agents (NMBA) sensitization by cross-reactivity. This hypothesis is supported by a higher prevalence of quaternary ammonium (QA)-specific IgE in the professionally exposed populations, such as hairdressers, cleaners, or healthcare workers, suggesting that the sensitization happens with structurally similar compounds present in the environment. This review summarizes the newest knowledge about QAC and their role in hypersensitivities. After describing the different QAC, their structure and use, the most relevant studies about the effects of QAC on the immune system will be reviewed and discussed.

11.
Org Lett ; 16(6): 1664-7, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24606049

RESUMO

An efficient biomimetic aerobic oxidative dehydrogenative alkenylation of arenes with allyl esters is presented. The reaction proceeds under an ambient pressure of oxygen with relatively low catalyst loading of palladium acetate, employing catalytic amounts of electron-transfer mediators (ETMs). This study represents a new environmentally friendly method for the synthesis of cinnamyl derivatives.


Assuntos
Cinamatos/síntese química , Paládio/química , Biomimética , Catálise , Cinamatos/química , Técnicas de Química Combinatória , Transporte de Elétrons , Ésteres , Estrutura Molecular , Oxirredução , Acoplamento Oxidativo , Oxigênio
12.
Org Lett ; 16(17): 4432-5, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25115599

RESUMO

An efficient ligand-promoted biomimetic aerobic oxidative dehydrogenative cross-coupling between arenes and nonbiased olefins is presented. Acridine as a ligand was found to significantly enhance the rate, the yield, and the scope of the reaction under ambient oxygen pressure, providing a variety of alkenylarenes via an environmentally friendly procedure.

13.
Org Lett ; 15(4): 816-9, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23368719

RESUMO

An efficient Pd-catalyzed decarboxylative cross-coupling reaction of simple enamides was achieved. Depending on the choice of the nitrogen-protecting group, a site-selective synthesis of mono- or diarylated framework(s) was performed under mild conditions. This unprecedented reactivity could be applied to the synthesis of a range of 2- or 2,4-diarylated nitrogen-containing bioactive derivatives.


Assuntos
Amidas/química , Compostos de Nitrogênio/química , Catálise , Estrutura Molecular , Paládio/química
14.
Org Lett ; 15(2): 278-81, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23272978

RESUMO

A convenient method for the copper(II)-catalyzed direct arylation of cyclic and nonaromatic enamides using diaryliodonium salts has been developed. The reaction demonstrates large functional group tolerance, good yields, and total regioselectivity with a C(3)-functionalization. The synthetic potential of this coupling was explored by using a range of readily accessible diaryliodonium salts and enamides.

15.
Org Lett ; 14(13): 3304-7, 2012 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-22694149

RESUMO

A mild and efficient method for the direct alkenylation of nonaromatic enamides was achieved through a palladium(II)-catalyzed C-H functionalization. The reaction scope includes cyclic and acyclic enamides and a range of activated alkenes. This approach represents the first successful direct C(3)-functionalization of nonaromatic cyclic enamides.


Assuntos
Amidas/síntese química , Compostos Organometálicos/química , Paládio/química , Alquilação , Amidas/química , Catálise , Estrutura Molecular , Estereoisomerismo
16.
Org Lett ; 14(17): 4622-5, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22913435

RESUMO

An efficient domino approach for the diastereoselective synthesis of polyfunctionalized nitrogen-fused tetrahydroquinoline frameworks under mild conditions has been developed. The scope and limitation of this transformation were investigated by using a range of readily accessible enamides and benzyl azides. This method is also applicable to the formation of 2,3-functionalized enamides.

17.
Org Lett ; 14(3): 844-7, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22260530

RESUMO

An efficient and versatile synthesis of a polycyclic diazinic system starting from oxazine has been developed using a two-step Michael/retro Michael and cyclization sequence. The substrates were synthesized with good to high yields giving rapid access to molecular diversity.


Assuntos
Compostos Heterocíclicos/síntese química , Oxazinas/química , Aminas/química , Ciclização , Estrutura Molecular
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