24 documents found, page 1 of 3
Selective synthesis of 3-(1H-Tetrazol-5-yl)-indoles from 2H-Azirines and Arynes
Grosso, Carla; Alves, Cláudia; Sase, Terver J.; Alves, Nuno G.; Cardoso, Ana L.; Melo, Teresa M. V. D. Pinho e; Lemos, AmericoA new selective synthetic approach to indole derivatives bearing a tetrazole moiety has been developed. Arynes, generated in situ from o-(trimethylsilyl)aryl triflates and KF, reacted smoothly with 2-(2-benzyl-2H-tetrazol-5-yl)-2H-azirines to give 3-(2-benzyl-2H-tetrazol-5-yl)-indole derivatives with high selectivity. Deprotection of the tetrazole moiety gave 3-(1H-tetrazol-5-yl)-indole derivatives.
Diels-Alder Cycloaddition Reactions in Sustainable Media
Soares, Maria I. L.; Cardoso, Ana L.; Melo, Teresa M. V. D. Pinho eDiels-Alder cycloaddition reaction is one of the most powerful strategies for the construction of six-membered carbocyclic and heterocyclic systems, in most cases with high regio- and stereoselectivity. In this review, an insight into the most relevant advances on sustainable Diels-Alder reactions since 2010 is provided. Various environmentally benign solvent systems are discussed, namely bio-based derived solv...
Global Women’s Breakfast (GWB): #UnidaspelaQuímica
Aguiar-Ricardo, Ana; Alves, Arminda; Antunes, M. Cristina; Batalha, Filipa; Oliveira Brett, Ana Maria; Camões, Filomena; Cardoso, Ana L.Global Women’s Breakfast (GWB): #BoundbyChemistry. Global Women’s Breakfast is an initiative of the International Union of Pure and Applied Chemistry, aiming to give women scientists, from all over the world, the opportunity to know each other, communicating virtually and sharing their experiences. Many countries joined this initiative and Portugal was not an exception, with its participation already at the fir...
Reduction of Oximes and Hydrazones: Asymmetric and Diastereoselective Approaches
Ribeiro, João L. P.; Alves, Cláudia; Cardoso, Ana L.; Lopes, Susana M. M.; Pinho e Melo, Teresa M. V. D.The asymmetric reduction of oximes and hydrazones is an attractive and versatile strategy for the synthesis of chiral amines, which are valuable building blocks in organic synthesis. This review summarizes the relevant developments, made in the last decade, on the enantioselective and diastereoselective reduction of oximes and hydrazones involving metal-catalyzed hydrogenation/hydrogenolysis reactions, hydride ...
One-Pot Synthetic Approach to Dipyrromethanes and Bis(indolyl)methanes via Nitr...
Cardoso, Ana L.; Lopes, Susana M. M.; Grosso, Carla; Pineiro, Marta; Lemos, Américo; Pinho e Melo, Teresa M. V. D.A one-pot regio- and stereoselective synthesis of a dipyrromethane and a bis(indolyl)methane based on two consecutive reactions of nitrosoalkenes with pyrrole or indole, respectively, is described as an experiment to be carried out by upper-division undergraduate students in a laboratory classroom. Importantly, the ability of electrophilic conjugated nitrosoalkenes to react via Michael addition or hetero-Diels−...
One-Pot Synthetic Approach to Dipyrromethanes and Bis(indolyl)methanes via Nitr...
Cardoso, Ana L.; Lopes, Susana M. M.; Grosso, Carla; Pineiro, Marta; Lemos, Americo; Pinho e Melo, Teresa M. V. D.A one-pot regio- and stereoselective synthesis of a dipyrromethane and a bis(indolyl)methane based on two consecutive reactions of nitrosoalkenes with pyrrole or indole, respectively, is described as an experiment to be carried out by upper-division undergraduate students in a laboratory classroom. Importantly, the ability of electrophilic conjugated nitrosoalkenes to react via Michael addition or hetero-Diels-...
Asymmetric neber reaction in the Synthesis of Chiral 2-(Tetrazol-5-yl)-2H-Azirines
Alves, Claudia; Grosso, Carla; Barrulas, Pedro; Paixao, Jose A.; Cardoso, Ana L.; Burke, Anthony J.; Lemos, Americo; Pinho e Melo, Teresa M. V. D.A successful one-pot methodology for the synthesis of chiral 2-tetrazolyl-2H-azirines has been established, resorting to organocatalysis. The protocol involves the in situ tosylation of beta-ketoxime-1H-tetrazoles followed by the Neber reaction, in the presence of chiral organocatalysts. Among the organocatalysts studied a novel thiourea catalyst derived from 6 beta-aminopenicillanic acid afforded excellent ena...
Asymmetric Neber Reaction in the Synthesis of Chiral 2-(Tetrazol-5-yl)-2H-Azirines
Alves, Cláudia; Grosso, Carla; Barrulas, Pedro; Paixão, José A.; Cardoso, Ana L.; Burke, Anthony J.; Lemos, Américo; Melo, Teresa M. V. D. Pinho eA successful one-pot methodology for the synthesis of chiral 2-tetrazolyl-2H-azirines has been established, resorting to organocatalysis. The protocol involves the in situ tosylation of β-ketoxime-1H-tetrazoles followed by the Neber reaction, in the presence of chiral organocatalysts. Among the organocatalysts studied a novel thiourea catalyst derived from 6β-aminopenicillanic acid afforded excellent enantiosel...
Roles of Microglial and Monocyte Chemokines and Their Receptors in Regulating A...
Guedes, Joana R.; Lao, Taotao; Cardoso, Ana L.; El Khoury, JosephChemokines and their receptors have been shown to affect amyloid-β (Aβ) and tau pathologies in mouse models of Alzheimer's disease (AD) by regulating microglia and monocyte-associated neuroinflammation, microglial movement and monocyte recruitment into the brain. These cells in turn can promote and mediate Aβ phagocytosis and degradation and tau phosphorylation. In this review we discuss published work in this ...
Hetero-Diels-Alder approach to Bis(indolyl)methanes
Grosso, Carla; Cardoso, Ana L.; Rodrigues, Maria Joao; Marques, Catia; Barreira, Luísa; Lemos, Americo; Pinho e Melo, Teresa M. D. V.A novel synthetic approach to bis(indolyl)methanes has been established. Our one-pot synthetic strategy based on two consecutive hetero-Diels-Alder cycloaddition reactions of electrophilic conjugated nitrosoalkenes with indoles was extended to a range of new 1-hydroxyiminomethyl-bis(indolyl) methanes. Furthermore, a similar and broad range approach was applied to the synthesis of previously unknown 1-hydrazonom...