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1.
J Am Chem Soc ; 140(21): 6522-6526, 2018 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-29754491

RESUMO

Herein we disclose an efficient method for the conversion of carboxylic acids to trifluoromethyl groups via the combination of photoredox and copper catalysis. This transformation tolerates a wide range of functionality including heterocycles, olefins, alcohols, and strained ring systems. To demonstrate the broad potential of this new methodology for late-stage functionalization, we successfully converted a diverse array of carboxylic acid-bearing natural products and medicinal agents to the corresponding trifluoromethyl analogues.


Assuntos
Ácidos Carboxílicos/química , Hidrocarbonetos Fluorados/síntese química , Descarboxilação , Hidrocarbonetos Fluorados/química , Estrutura Molecular
2.
Nature ; 547(7661): 79-83, 2017 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-28636596

RESUMO

The functionalization of carbon-hydrogen (C-H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence. Although many C-H functionalization reactions involve C(sp3)-C(sp2) coupling, there is a growing demand for C-H alkylation reactions, wherein sp3 C-H bonds are replaced with sp3 C-alkyl groups. Here we describe a polarity-match-based selective sp3 C-H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C-H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl-alkyl fragment coupling. The sp3 C-H alkylation is highly selective for the α-C-H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry.


Assuntos
Carbono/química , Técnicas de Química Sintética/métodos , Hidrogênio/química , Alquilação , Catálise , Ligação de Hidrogênio , Níquel/química , Oxirredução/efeitos da radiação
3.
Org Lett ; 18(17): 4304-7, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27513364

RESUMO

Highly enantioenriched chiral allenylsilanes 4 were prepared in high yield through a scalable synthetic sequence, employing a modified copper-catalyzed SN2' reaction. These reagents were used for the production of enantioenriched homoproparglylic ethers 5, which were subjected to titanium alkoxide-mediated reductive coupling with acetylenic esters to produce (E,E)-dienes 6 bearing α,ß,γ,δ-unsaturated esters. Both enantiomers of nuclear factor of activated T-cells-68 (NFAT-68) were synthesized in five steps with the sequential use of the two methods.


Assuntos
Hidroquinonas/síntese química , Óxidos/química , Silanos/química , Titânio/química , Hidroquinonas/química , Estrutura Molecular , Estereoisomerismo
4.
J Am Chem Soc ; 135(43): 16074-7, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24107144

RESUMO

The direct α-amination of ketones, esters, and aldehydes has been accomplished via copper catalysis. In the presence of catalytic copper(II) bromide, a diverse range of carbonyl and amine substrates undergo fragment coupling to produce synthetically useful α-amino-substituted motifs. The transformation is proposed to proceed via a catalytically generated α-bromo carbonyl species; nucleophilic displacement of the bromide by the amine then delivers the α-amino carbonyl adduct while the catalyst is reconstituted. The practical value of this transformation is highlighted through one-step syntheses of two high-profile pharmaceutical agents, Plavix and amfepramone.


Assuntos
Aminas/química , Ticlopidina/análogos & derivados , Aldeídos/química , Brometos/química , Catálise , Clopidogrel , Cobre/química , Dietilpropiona/síntese química , Ésteres/química , Ticlopidina/síntese química
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