Micro-damage of Ti–6Al–4V alloy under hypervelocity projectile impact

Li, H.T.; Zhang, Y.M.; Yang, Danni

doi:10.1016/s0921-5093(00)01019-4

Cited by 19 publications

(9 citation statements)

References 2 publications

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“…However, recent years have witnessed a surge in the development of catalytic systems based on inexpensive metals[5c] such as Cu, Mn,[5a], [5b], Fe, Ni and Co.[13a], Emphasis has also been laid on using heterogeneous catalytic N ‐alkylation systems based on Pd,[12b], [14a], Au,[12a] Ag, W, Cu and Ni , . It is noteworthy that ruthenium‐based N ‐alkylation systems have enjoyed great success and have been reported with several types such as [RuX 2 (PPh 3 ) 3 ] (X = Cl,, [15e], [15r], [15s], [15t] Br[15f]), [RuH 2 (PPh 3 ) 4 ],[15e] [RuHCl(PPh 3 ) 3 ],[15f] Ru–Phosphine complexes,[15d], [15f], [15g], [15h], [15i], [15m], [15n], [15o], [15p], [15x] Ru‐cyclopentadienyl complexes, Ru–amine complexes,[15j], [15u] Ru– N ‐Heterocyclic complexes[15d], [15k] and even ruthenium–pincer complexes.…”

Section: Introductionmentioning

confidence: 99%

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

et al. 2019

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We report the use of ruthenium–NNN‐pincer complexes of the type (R2NNN)RuCl2(PPh3) (R = tBu, iPr, Cy and Ph) for the catalytic N‐alkylation of primary amines under solvent‐free conditions. For the first time, the base that is required to promote these reactions is generated in situ from the alcohol by the use of sodium. The resulting sodium alkoxide regenerates the alcohol substrate while acting as the water scavenger thus mitigating the need of an additional base. Among the catalysts screened, (tBu2NNN)RuCl2(PPh3) (0.02 mol‐%) gives very high turnovers and good yields at 140 °C. The (tBu2NNN)RuCl2(PPh3) catalyzed N‐alkylation tolerates a variety of amine and alcohol substrates. While excellent turnover (29000) was obtained for the (tBu2NNN)RuCl2(PPh3) (0.002 mol‐%) catalyzed alkylation of aniline with cyclohexyl methanol, the turnovers obtained in the corresponding catalytic methylation of p‐anisidine was also very high (12000). The (tBu2NNN)RuCl2(PPh3) catalyzed reactions have also been accomplished under open‐vessel conditions resulting in a net dehydrogenative coupling reaction. This protocol has been used to transform benzene‐1,2‐diamines to benzimidazoles with high productivity (12000 turnovers). DFT studies indicate that while β‐hydride elimination is rate‐determining (RDTS: 24.31 kcal/mol) for the alcohol dehydrogenation segment which is endothermic, insertion of the imine is rate‐determining (RDTS: 11.26 kcal/mol) for its hydrogenation that is exothermic.

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Section: Introductionmentioning

confidence: 99%

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

et al. 2019

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“…In an effort to overcome recycling and separation issues associated with these expensive metal complexes, heterogeneous catalysts have been extensively explored . Both Ru NPs supported on Fe 3 O 4 and Ag NPs have shown a strong potential . Bimetallic catalysts have proven particularly attractive, enabling synergistic effects (Au−Pd) and also allowing “dilution” of the precious metal with a cheaper one (Ag−Cu, Pt−Sn, Cu‐Au, Pd‐Zn, Co‐Rh).…”

Section: Introductionmentioning

confidence: 99%

Plasma‐Made (Ni_0.5Cu_0.5)Fe₂O₄ Nanoparticles for Alcohol Amination under Microwave Heating

Dumaresq

Segalla

et al. 2019

ChemCatChem

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Amine N‐alkylation is a process involved in the production of a wide range of chemicals. Here we describe the synthesis of well‐defined (Ni0.5Cu0.5)Fe2O4 magnetic nanoparticles by plasma induction, and their successful application to amine N‐alkylation using alcohols as coupling agents through a borrowing hydrogen pathway. Plasma induction allows precise morphology and size control over nanoparticle synthesis, while allowing the one‐pot production of decagram quantities of material. Up to date, such nanoparticles have never been applied for organic reactions. By coupling high‐end characterization techniques with catalytic optimization, we showed that small Cu(0) satellite nanoparticles played an essential role in alcohol oxidation, whereas both Ni and Cu were required for the last step of the reaction. Using elemental mapping, we demonstrated that catalyst deactivation occurred through a leaching/re‐deposition mechanism of Cu and Ni. The reactions were conducted under microwave conditions, which exerted a positive effect on catalytic activity. Finally, the catalyst was active at low metal loadings (2 mol%) even on the gram‐scale, and affording unprecedented TON for this reaction catalyzed by Ni/Cu bimetallic systems (19).

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“…Also, heterogeneous catalysis has been explored , Heterogeneous catalysts containing metals such as Pd, Ru, Au, Ag and Fe, have been used for N‐alkylation of amines with alcohols. However, they require multistep and complex procedures and often result in reduced activity and selectivity.…”

Section: Introductionmentioning

confidence: 99%

Self‐Suspended Nanoparticles for N‐Alkylation Reactions: A New Concept for Catalysis

2019

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The catalytic activity of snowman‐like and core‐shell Fe3O4/Au nanoparticles (NPs), obtained through a “wet chemistry” approach which directly restitutes nanocatalysts stable and highly active in the reaction medium, was tested towards N‐alkylation reactions. The nanocatalysts were tested for the synthesis of secondary amines. The core‐shell NPs, thanks to the surface properties, homogeneous dispersion and intimate connection with reagents in the catalyst medium, exhibited an excellent catalytic activity (e. g. >99 % yield and conversion of aniline in very short time and mild conditions). Owing to the magnetic part, the nanoparticles can be easily separated and reused, showing an almost stable activity after 10 cycles.

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Micro-damage of Ti–6Al–4V alloy under hypervelocity projectile impact

Cited by 19 publications

References 2 publications

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

Plasma‐Made (Ni_0.5Cu_0.5)Fe₂O₄ Nanoparticles for Alcohol Amination under Microwave Heating

Self‐Suspended Nanoparticles for N‐Alkylation Reactions: A New Concept for Catalysis

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Micro-damage of Ti–6Al–4V alloy under hypervelocity projectile impact

Cited by 19 publications

References 2 publications

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

N–Alkylation of Amines Catalyzed by a Ruthenium–Pincer Complex in the Presence of in situ Generated Sodium Alkoxide

Plasma‐Made (Ni0.5Cu0.5)Fe2O4 Nanoparticles for Alcohol Amination under Microwave Heating

Self‐Suspended Nanoparticles for N‐Alkylation Reactions: A New Concept for Catalysis

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Plasma‐Made (Ni_0.5Cu_0.5)Fe₂O₄ Nanoparticles for Alcohol Amination under Microwave Heating