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The development of efficient and eco-friendly methods for the synthesis of elaborate amines is highly desired as they are valuable chemicals. The catalytic alkylation of amines using alcohols as alkylating agents, through the so-called borrowing hydrogen process, satisfies several of the principles of green chemistry. In this paper, four neutral half-sandwich complexes of Ru(II), Rh(III), and Ir(III) have been synthesized and tested as catalysts in the N-benzylation of amines with benzyl alcohol. The new derivatives contain a N^N′ anionic ligand derived from 5-(pyridin-2-ylmethylene)hydantoin (Hpyhy) that has never been tested in metal complexes with catalytic applications. In particular, the Ir derivatives, [(Cp*)IrX(pyhy)] (X = Cl or H), exhibit high activity along with good selectivity in the process. Indeed, the scope of the optimized protocol has been proved in the benzylation of several primary and secondary amines. The selectivity towards monoalkylated or dialkylated amines has been tuned by adjusting the amine:alcohol ratio and the reaction time. Experimental results support a mechanism consisting of three consecutive steps, two of which are Ir catalyzed, and a favorable condensation step without the assistance of the catalyst. Moreover, an unproductive competitive pathway can operate when the reaction is performed in open-air vessels, due to the irreversible release of H2. This route is hampered when the reaction is carried out in close vessels, likely because the release of H2 is reversed through metal-based heterolytic cleavage. From our viewpoint, these results show the potential of the new catalysts in a very attractive and promising methodology for the synthesis of amines., El desarrollo de métodos eficientes y ecológicos para la síntesis de aminas elaboradas es muy deseable, ya que son sustancias químicas valiosas. La alquilación catalítica de aminas utilizando alcoholes como agentes alquilantes, mediante el llamado proceso de préstamo de hidrógeno, satisface varios de los principios de la química verde. En este artículo, se sintetizaron y probaron cuatro complejos semisándwich neutros de Ru(II), Rh(III) e Ir(III) como catalizadores en la N -bencilación de aminas con alcohol bencílico. Las nuevas derivadas contienen un N ^ N′ ligando aniónico derivado de 5-(piridin-2-ilmetileno)hidantoína (Hpyhy) que nunca se ha probado en complejos metálicos con aplicaciones catalíticas. En particular, los derivados de Ir, [(Cp*)IrX(pyhy)] (X = Cl o H), muestran una alta actividad junto con una buena selectividad en el proceso. De hecho, el alcance del protocolo optimizado ha sido probado en la bencilación de varias aminas primarias y secundarias. La selectividad hacia las aminas monoalquiladas o dialquiladas se ha ajustado ajustando la relación amina:alcohol y el tiempo de reacción. Los resultados experimentales respaldan un mecanismo que consta de tres pasos consecutivos, dos de los cuales son catalizados por Ir y un paso de condensación favorable sin la ayuda del catalizador. Además, una vía competitiva improductiva puede operar cuando la reacción se realiza en recipientes al aire libre,2 . Esta ruta se ve obstaculizada cuando la reacción se lleva a cabo en recipientes cerrados, probablemente porque la liberación de H 2 se invierte a través de la escisión heterolítica basada en metales. Desde nuestro punto de vista, estos resultados muestran el potencial de los nuevos catalizadores en una metodología muy atractiva y prometedora para la síntesis de aminas.

Cancer designate a group of heterogeneous genetic diseases characterized by uncontrolled cell proliferation. Problems in regard to effectiveness, safety as well as development of resistance to treatment foment the need for researches on new molecules with antitumor potential. Hydantoin derivatives are known to present biological activities such as antitumor and antinociceptive ones. This paper aimed at investigating the toxicity, antitumor, antinociceptive and antiinflammatory activities of the hydantoin derivative 3,5-diphenyl-imidazolidine - 2,4 – dione (IM-15). IM-15 did not induce hemolysis to the concentration of 2000 µg/mL, which suggested low toxicity in erythrocytes. In the pre-clinical acute toxicity trial, the IM-15 (300 or 2000 mg/kg, i.p.) induced a depressant effect on the Central Nervous System (CNS) and its LD50 (lethal dose 50%) was estimated at around 1000 mg/kg. The hydantoin derivative (12,5; 25 and 50 mg/kg, i.p.) reduced (p

Resumo: Reações para obtenção de derivados de hidantoína foram conduzidas a partir de aldeídos de cadeia curta e da 5,5-dimetilhidantoína. O acompanhamento das reações foi realizado por espectroscopia na região do infravermelho médio (MIR) por meio da formação de novas bandas características da estrutura do composto desejado. A análise MIR revelou que estas alterações espectrométricas ocorrem somente na reação com o formaldeído, indicando a formação do produto 1,3-bis(hidroximetil)-5,5-dimetilhidantoína, em presença de água. As bandas de absorção que confirmam a reação foram observadas em 3334 cm-1 (υ OH), 1770 e 1710 cm-1 (υ C=O) e em 1056 cm-1 (υ C-O), sendo esta última, atribuída ao grupo contendo hidroxila primária. A reação da 5,5-dimetil hidantoína com acetaldeído e com propanaldeído não ocorreu sob as condições adotadas neste trabalho. Abstract: Reactions to obtain hydantoin derivatives were carried out with 5,5-dimethylhydantoin and short-chain aldehydes. Monitoring of the reactions was performed using qualitative mid-infrared spectroscopy (MIR) through the formation of new bands characteristic of the desired product. MIR analysis showed that these spectrometric alterations occur only in the reaction with the formaldehyde, indicating the formation of the desired product, 1,3-bis (hydroxymethyl) 5,5-dimethylhydantoin, in the presence of water. The absorption bands that confirmed the reaction were observed at 3334 cm-1 (υ OH), 1770 and 1710 cm-1 (υ C=O) and 1056 cm-1 (υ C-O), the last of which is assigned to the group containing primary hydroxyl.