Selective Alkylation of Amines with Alcohols by Cp*–Iridium(III) Half-Sandwich Complexes

[Cp*Ir(Pro)Cl] (Pro = prolinato) was identified among a series of Cp*–iridium half-sandwich complexes as a highly reactive and selective catalyst for the alkylation of amines with alcohols. It is active under mild conditions in either toluene or water without the need for base or other additives, tolerates a wide range of alcohols and amines, and gives secondary amines in good to excellent isolated yields

Alcohol Amination with Aminoacidato Cp*Ir(III)-Complexes as Catalysts: Dissociation of the Chelating Ligand during Initiation

The use of aminoacidato Cp*Ir­(III)-complexes in catalytic alcohol amination reactions of primary and secondary alcohols with amines permits to carry out these transformations at very mild reaction conditions without the use of an additional base. Herein we discuss the fate of the chelating aminoacidato ligands upon initiation of Cp*Ir­(III)-complexes from a mechanistic perspective. Catalyst initiation has been followed by NMR using isotopically labeled ¹³C,¹⁵N-glycinato complexes

Alcohol Amination with Aminoacidato Cp*Ir(III)-Complexes as Catalysts: Dissociation of the Chelating Ligand during Initiation

The use of aminoacidato Cp*Ir­(III)-complexes in catalytic alcohol amination reactions of primary and secondary alcohols with amines permits to carry out these transformations at very mild reaction conditions without the use of an additional base. Herein we discuss the fate of the chelating aminoacidato ligands upon initiation of Cp*Ir­(III)-complexes from a mechanistic perspective. Catalyst initiation has been followed by NMR using isotopically labeled ¹³C,¹⁵N-glycinato complexes

Alcohol Amination with Ammonia Catalyzed by an Acridine-Based Ruthenium Pincer Complex: A Mechanistic Study

The mechanistic course of the amination of alcohols with ammonia catalyzed by a structurally modified congener of Milstein’s well-defined acridine-based PNP-pincer Ru complex has been investigated both experimentally and by DFT calculations. Several key Ru intermediates have been isolated and characterized. The detailed analysis of a series of possible catalytic pathways (e.g., with and without metal–ligand cooperation, inner- and outer-sphere mechanisms) leads us to conclude that the most favorable pathway for this catalyst does not require metal–ligand cooperation

Estimativas de Herdabilidade e Correlação Genética para Características de Crescimento na Fase de Pré-desmama e Medidas de Perímetro Escrotal ao Sobreano em Bovinos Angus-Nelore Heritability Estimates and Genetic Correlation of Growth Characteristics in the Preweaning Period and Scrotal Circumference Measurement at Yearling for Angus-Nelore Beef Cattle

Os dados utilizados neste estudo são originários de 53.938 bovinos puros e cruzados (Angus x Nelore), coletados em várias regiões do Brasil e da Argentina nascidos entre 1987 e 1998. O objetivo do trabalho foi verificar as herdabilidades e as correlações existentes entre as características de crescimento e as medidas de perímetro escrotal (PE). As variáveis estudadas foram ganho médio diário do nascimento à desmama (GMDND), dias para ganhar 160 kg do nascimento à desmama (D160), peso à desmama (PD) e perímetro escrotal ao sobreano (PE). Foi utilizado o método da Máxima Verossimilhança Restrita, com o programa computacional MTDFREML e um modelo animal bi-caráter. Para as características de crescimento, foram incluídos, como efeitos fixos, o grupo contemporâneo de desmama, a interação das composições raciais dos pais do produto; como covariável, a idade da mãe ao parto; e como aleatórios, os efeitos direto e materno. Para a característica PE, no modelo utilizado, consideraram-se os efeitos linear e quadrático da idade ao sobreano e o peso ao sobreano, a interação das proporções raciais, maternas e paternas e o grupo contemporâneo de sobreano foram introduzidos no modelo como efeitos fixos e o efeito direto do animal como aleatório. As estimativas de herdabilidade foram 0,25, 0,13, 0,23 e 0,21 para GMDND, D160, PD e PE respectivamente. As estimativas de correlações com PE foram 0,17, -0,17 e 0,16 para GMDND, D160 e PD, respectivamente. Os resultados sugerem que as características analisadas podem ser selecionadas conjuntamente em programas de seleção.<br>The data utilized in this work were originated from 53.938 pure and crossbred (Angus x Nelore), collected in different regions of Brazil and Argentina born from 1987 to 1998 were analyzed. The objectives of this work were to verity the heritabilities and correlation among the growing and scrotal circumference traits. The variables analyzed were the average daily gain from birth to weaning (ADGBW), days to reach 160 kg from birth to weaning (D160), weaning weight (WW) and scrotal circumference at yearling (CP). The method of restricted Maximum Likelihood and computational program MTDFREML were used with a multitrait animal model. For the growing trait, the model included the fixed effects of contemporary groups at weaning, the interaction of breeds parents of animal, the age of dam at parturition and age at weaning as covariable and the direct and maternal as random effects. For the SP the fixed effects included in the model were the linear and quadratic effects of age at yearling and weight, contemporary group at yearling and interaction composite breed sire and dam a direct animal effect as random effect. The heritability estimates were .25, .13, .23 and .21 for ADGBW, D160, WW and CP, respectively. The correlation estimates with SP were:.0,17, -.17 and .16 for ADGBW, D160, and WW respectively. These results suggest that the trait analyzed can be chosen together at the selection programs