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1.
Org Biomol Chem ; 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34985096

RESUMO

A thioether directed acyloxylation of arenes has been realized via Cp*Rh(III)-catalyzed C-H activation and subsequent coupling with carboxylic acids. This new method showed high functional group compatibility and broad substrate scope. Primary mechanistic studies have been conducted and a tentative reaction mechanism was proposed. It represents the first example of a thioether-directed Cp*Rh(III)-catalyzed C(sp2)-H acyloxylation reaction.

2.
J Org Chem ; 86(23): 17063-17070, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34797073

RESUMO

A tandem rhodium(III)-catalyzed system was established to access 3,4-dihydroisoquinolin-1(2H)-one by coupling of N-methoxy-3-methylbenzamide with 2-methylidenetrimethylene carbonate. This one-pot synthesis protocol processed smoothly under mild reaction conditions. Moreover, a total of 28 examples, broad substrate scope, and high functional-group compatibility were observed. Preliminary mechanism studies were also conducted and demonstrated that the rhodium(III) catalyst played a vital role in the C-H-allylation and N-alkylation cyclization process.

3.
Org Biomol Chem ; 19(39): 8487-8491, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34545904

RESUMO

An efficient and practical approach for the synthesis of medicinally important acridones was developed from anthranils and commercially available arylboronic acids by a tandem copper(I)-catalyzed electrophilic amination/Ag(I)-mediated oxidative annulation strategy. This new and straightforward protocol displayed a broad substrate scope (25 examples) and high functional group tolerance. What's more, a possible mechanistic proposal was also presented.

4.
Org Lett ; 23(15): 5719-5723, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34286981

RESUMO

A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.

5.
Org Biomol Chem ; 19(5): 1155, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33521805

RESUMO

Correction for 'Rhodium(iii)-catalyzed oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols' by Jidan Liu et al., Org. Biomol. Chem., 2021, DOI: .

6.
Org Biomol Chem ; 19(5): 993-997, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33443262

RESUMO

An efficient Rh(iii)-catalyzed C-H oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols by merging tandem C-H and C-C cleavage was developed. This transformation features mild reaction conditions, high regioselectivity, and excellent functional group compatibility. The resulting ß-aryl ketone derivatives can be readily transformed into 7-azaindole-containing π-extended polycyclic heteroarenes.

7.
Bioorg Med Chem Lett ; 30(4): 126925, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901379

RESUMO

A series of novel indole-pyrazoline hybrid derivatives were designed, synthesized, and evaluated for topoisomerase 1 (Top1) inhibitory activity. Top1-mediated relaxation assays showed that our synthesized compounds had variable Top1 inhibitory activity. Among these compounds, 3-(5-(naphthalen-1-yl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-1-(phenylsulfonyl)-1H-indole (6n) was found to be a strong Top1 inhibitor with better inhibitory activity than CPT and hit compounds. Our further experiments rationalized the mode of action for this new type of inhibitors, which showed no significant binding to supercoiled DNA.


Assuntos
DNA Topoisomerases Tipo I/química , Indóis/química , Pirazóis/química , Inibidores da Topoisomerase I/síntese química , Sítios de Ligação , DNA Topoisomerases Tipo I/metabolismo , DNA Super-Helicoidal/química , DNA Super-Helicoidal/metabolismo , Desenho de Fármacos , Humanos , Simulação de Dinâmica Molecular , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/metabolismo
8.
Chem Commun (Camb) ; 56(3): 423-426, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31822876

RESUMO

Iridium-catalyzed boron-hydrogen bond insertion reactions of trimethylamine-borane and sulfoxonium ylides have been demonstrated, furnishing α-boryl ketones in moderate to excellent yields in most cases (51 examples; up to 84%). This practical and scalable insertion reaction showed broad substrate scope, high functional-group compatibility and could be applied in late-stage modification of structurally complex drug compounds. Further synthetic applications were also demonstrated.

9.
Angew Chem Int Ed Engl ; 57(40): 13096-13100, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30252190

RESUMO

A cobalt-catalyzed decarboxylative Negishi coupling reaction of redox-active aliphatic esters with organozinc reagents was developed. The method enabled efficient alkyl-aryl, alkyl-alkenyl, and alkyl-alkynyl coupling reactions under mild reaction conditions with no external ligand or additive needed. The success of an in situ activation protocol and the facile synthesis of the drug molecule (±)-preclamol highlight the synthetic potential of this method. Mechanistic studies indicated that a radical mechanism is involved.

10.
Org Lett ; 19(21): 5868-5871, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-29047270

RESUMO

A novel cascade Cp*Rh(III)-catalyzed C-H alkylation/Cu(II)-promoted α-oxygenation which enabled a three-component carboxygenation of activated alkene is reported. Mild reaction conditions, broad substrate scope, and good functional group tolerance were observed. The synthetic utility of the protocol was showcased by the facile transformations of the product to a variety of structurally diverse molecules. Preliminary mechanistic studies were conducted.

11.
Org Lett ; 19(22): 6108-6111, 2017 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-29047277

RESUMO

A simple and efficient protocol for the regioselective synthesis of 5-aminooxazoles is disclosed. The reaction, catalyzed by a cheap Cp*Co(III) catalyst, starts from easily accessible N-(pivaloyloxy)amides and ynamides. Mild reaction conditions, a broad substrate scope, good functional group tolerance, and good to excellent yields were observed.

12.
ChemSusChem ; 10(11): 2360-2364, 2017 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-28471522

RESUMO

In this study, a MnI /AgI -based relay catalysis process is described for the one-pot synthesis of polycyclic products by a formal [3+2] and [4+2] cycloaddition reaction cascade. A manganese(I) complex catalyzed the first example of directed C-H allylation with allenes, setting the stage for an in situ Povarov cyclization catalyzed by silver(I). The reaction proceeds with high bond-forming efficiency (three C-C bonds), broad substrate scope, high regio- and stereoselectivity, and 100 % atom economy.


Assuntos
Compostos Alílicos/química , Reação de Cicloadição/métodos , Manganês/química , Prata/química , Catálise , Ciclização , Estereoisomerismo
13.
J Am Chem Soc ; 139(9): 3537-3545, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28177234

RESUMO

Fluorinated heterocycles play an important role in pharmaceutical and agrochemical industries. Herein, we report on the synthesis of four types of fluorinated heterocycles via rhodium(III)-catalyzed C-H activation of arenes/alkenes and versatile coupling with 2,2-difluorovinyl tosylate. With N-OMe benzamide being a directing group (DG), the reaction delivered a monofluorinated alkene with the retention of the tosylate functionality. Subsequent one-pot acid treatment allowed the efficient synthesis of 4-fluoroisoquinolin-1(2H)-ones and 5-fluoropyridin-2(1H)-ones. When N-OPiv benzamides were used, however, [4 + 2] cyclization occurred to provide gem-difluorinated dihydroisoquinolin-1(2H)-ones. Synthetic applications have been demonstrated and the ready availability of both the arene and the coupling partner highlighted the synthetic potentials of these protocols. Mechanistically, these two processes share a common process involving N-H deprotonation, C-H activation, and olefin insertion to form a 7-membered rhodacycle. Thereafter, different reaction pathways featuring ß-F elimination and C-N bond formation are followed on the basis of density functional theory (DFT) studies. These two pathways are DG-dependent and led to the open chain and cyclization products, respectively. The mechanistic rationale was supported by detailed DFT studies. In particular, the origins of the intriguing selectivity in the competing ß-F elimination versus C-N bond formation were elucidated. It was found that ß-F elimination is a facile event and proceeds via a syn-coplanar transition state with a low energy barrier. The C-N bond formation proceeds via a facile migratory insertion of the Rh-C(alkyl) into the Rh(V) amido species. In both reactions, the migratory insertion of the alkene is turnover-limiting, which stays in good agreement with the experimental studies.

14.
Org Lett ; 17(21): 5404-7, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26451846

RESUMO

Cp*Co(III)-catalyzed annulations of 2-alkenylphenols with CO for the synthesis of coumarin derivatives have been developed. The reaction features mild reaction conditions, broad substrate scope, and good functional group tolerance. Preliminary mechanistic studies were conducted, suggesting that C-H activation is the turnover limiting step. Furthermore, the efficiency of this reaction was demonstrated by the rapid total synthesis of three natural products herniarin, xanthyletin, and seselin.


Assuntos
Alcenos/química , Cobalto/química , Cumarínicos/síntese química , Fenóis/química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Catálise , Cumarínicos/química , Estrutura Molecular , Umbeliferonas/síntese química , Umbeliferonas/química
15.
Org Lett ; 17(12): 2972-5, 2015 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-26061180

RESUMO

A simple and efficient method for the synthesis of diaryl 1,2-diketones has been developed. The reaction represents the first example of diaryl 1,2-diketones that are synthesized directly from arylboronic acids and arylpropiolic acids by a radical pathway in moderate to good yields. This reaction proceeds under mild reaction conditions and with good tolerance of a variety of functional groups. Preliminary mechanistic studies were conducted.


Assuntos
Ácidos Borônicos/química , Cetonas/síntese química , Manganês/química , Catálise , Cetonas/química , Estrutura Molecular , Acoplamento Oxidativo
16.
Chem Commun (Camb) ; 51(50): 10240-3, 2015 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-26021599

RESUMO

Cp*Rh(III)- and Cp*Ir(III)-catalysed direct C-H arylation with quinone diazides as efficient coupling partners is disclosed. This redox-neutral protocol offers a facile, operationally simple and environmentally benign access to arylated phenols. The reaction represents the first example of Cp*Ir(III)-catalysed C-H direct arylation reaction.


Assuntos
Azidas/química , Irídio/química , Compostos Organometálicos/química , Fenóis/química , Fenóis/síntese química , Quinonas/química , Ródio/química , Técnicas de Química Sintética
17.
Chem Commun (Camb) ; 51(1): 77-80, 2015 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-25383663

RESUMO

Succession of C-H activation and C-C activation was achieved by using a single rhodium(III) catalyst. Vinylcyclopropanes were used as versatile coupling partners. Mechanistic studies suggest that the olefin insertion step is rate-determining and a facile ß-carbon elimination is involved, which represents a novel ring opening mode of vinylcyclopropanes.


Assuntos
Carbono/química , Ciclopropanos/química , Hidrogênio/química , Ródio/química , Catálise , Complexos de Coordenação/química , Ciclização , Oxirredução , Estereoisomerismo , Compostos de Vinila/química
18.
Org Lett ; 16(24): 6412-5, 2014 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-25438098

RESUMO

A rhodium(III)-catalyzed C-H direct allylation reaction with 4-vinyl-1,3-dioxolan-2-ones has been developed. The reaction provides a facile and stereoselective access to substituted-(E)-allylic alcohols under mild and redox-neutral reaction conditions. Olefinic C-H activation is applicable, giving multifunctionalized skipped dienes in good yields. Minimal double-bond migration was observed.


Assuntos
Alcenos/química , Dioxolanos/química , Propanóis/química , Propanóis/síntese química , Ródio/química , Compostos de Vinila/química , Catálise , Ciclização , Ligação de Hidrogênio , Estrutura Molecular , Estereoisomerismo
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