Alkali and alkaline-earth metals

Hill, Michael S.

doi:10.1039/b612595f

Cited by 6 publications

(3 citation statements)

References 150 publications

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“…In order to avoid chemical waste produced in time-consuming multistep syntheses, hydroamination was discovered as an alternative access to nitrogen-containing molecules. Hydroamination, the direct addition of amine N−H bonds to C−C multiple bonds, attracted the attention of many researchers and thus was intensely studied for the last decades. − Catalytic hydroamination was investigated for a wide range of complexes of various metals, such as alkali metals, ,,,, early transition metals, ,, late transition metals, ,,,,,, and lanthanides and actinides, ,− ,− ,− and very recently aluminum compounds were studied for hydroamination reactions. , Early transition metal and late transition metal catalysts have to be distinguished. Complexes of early transition metals, such as group 4 ,,,,, and the rare earth elements, ,− ,− ,− are highly efficient catalysts for the hydroamination, but the synthetic application is limited by their high sensitivity toward moisture and air and their low tolerance to polar functional groups.…”

Section: Introductionmentioning

confidence: 99%

“…Hydroamination, the direct addition of amine N-H bonds to C-C multiple bonds, attracted the attention of many researchers and thus was intensely studied for the last decades. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Catalytic hydroamination was investigated for a wide range of complexes of various metals, such as alkali metals, 3,5,15,20,21 early transition metals, 1,9,20 late transition metals, 1,7,9,12,14,15,20 and lanthanides and actinides, 1,7-9,11-13,15-17 and very recently aluminum compounds were studied for hydroamination reactions. 22,23 Early transition metal and late transition metal catalysts have to be distinguished.…”

Section: ' Introductionmentioning

confidence: 99%

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2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

2011

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The heteroleptic iodo complexes [(DIP2pyr)MI(THF) n ] (M = Ca, Sr (n = 3); Ba (n = 4); (DIP2pyr)− = 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl) were synthesized by reaction of [(DIP2pyr)K] with anhydrous alkaline earth metal diiodides. All complexes are monomeric in the solid state. A κ3-coordination mode of the (DIP2pyr)− ligand was observed for the strontium and the barium compounds, while the analogous calcium derivative is κ2-coordinated in the solid state. However, VT-1H NMR studies of [(DIP2pyr)CaI(THF)3] indicate a symmetrically coordinated (DIP2pyr)− ligand in solution. Computational studies confirm the different coordination modes in solution and in the solid state. The preferred κ2-coordination mode observed in the solid state might be a result of temperature or/and crystal-packing effects. Furthermore, the calcium and strontium amido complexes [(DIP2pyr)M{N(SiMe3)2}(THF)2] (M = Ca, Sr) were prepared by reaction of [(DIP2pyr)MI(THF) n ] (M = Ca, Sr (n = 3)) with [K{N(SiMe3)2}]. Both compounds were investigated for the intramolecular hydroamination of aminoalkenes. Both catalysts showed a good activity, and the best results were obtained for the calcium complex [(DIP2pyr)Ca{N(SiMe3)2}(THF)2].

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Section: Introductionmentioning

confidence: 99%

Section: ' Introductionmentioning

confidence: 99%

2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

2011

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“…The hydroamination reaction, which is the direct addition of amine N–H bonds to C–C multiple bonds, has been intensely studied in the last decades. − Catalytic hydroamination was investigated for a wide range of complexes of various metals, such as main group metals, ,,,− early transition metals, ,,, late transition metals, ,,,,,,− and f-elements. ,− ,− ,− Early transition metal and late transition metal catalysts show different forms of substrate activation. Generally complexes of the early transition metals, the lanthanides, and electron-poor main group metals activate the amine function .…”

Section: Introductionmentioning

confidence: 99%

Comparison of Decamethyldizincocene [(η⁵-Cp)₂Zn₂] versus Decamethylzincocene [Cp₂Zn] and Diethylzinc Et₂Zn As Precatalysts for the Intermolecular Hydroamination Reaction

et al. 2012

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A comparison of the Zn−Zn bonded species [(η 5 -Cp*) 2 Zn 2 ] versus the related organometallic zinc compound [Cp* 2 Zn] and ZnEt 2 for the intermolecular hydroamination reaction in the presence of equimolar amounts of [PhNMe 2 H][B(C 6 F 5 ) 4 ] is reported. All compounds show high reaction rates under mild conditions and a good functional group tolerance for the addition of aniline derivatives to primary alkynes. Within this series the metallocene [Cp* 2 Zn] is the most active one, whereas the zinc−zinc bonded species [(η 5 -Cp*) 2 Zn 2 ] shows the best selectivity. Most remarkable is the unexpected excellent catalytic performance of the zinc−zinc bonded species [(η 5 -Cp*) 2 Zn 2 ].

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Aquifer permeability change caused by a near‐field earthquake, Canterbury, New Zealand

Rutter

Cox

Ward

et al. 2016

Water Resources Research

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The M W 7.1 Darfield (Canterbury) earthquake, 4 September 2010, generated widespread hydrological effects in New Zealand ranging from instantaneous changes of piezometric levels, to more sustained postseismic changes in spring flow, river discharge and groundwater levels, and increased turbidity and declined yields of water abstracted from wells. Four years later, piezometric levels remained elevated in deeper (>40 m) aquifers along the north-western (upper) side of the Canterbury Plains near the Greendale Fault, with changes in mean piezometric level reaching 113 m. Linear reservoir modeling (eigen modeling) suggests that sustained high groundwater was not the result of changes in abstraction or land surface recharge.Step-drawdown tests at six wells within 15 km of Greendale Fault were carried out prior to the earthquake and were retested following fault rupture. Eden-Hazel analysis of discharge/drawdown relationships discriminates potential sources of head losses, and how these changed (or otherwise) as a result of the earthquake. Objective application of Eden-Hazel analysis provided confidence levels for the interpretation, including when step tests provide reliable/unreliable estimates of transmissivity change. Increases in both aquifer losses and well losses were observed in four wells, reflecting both a change in sediment transmissivity and decrease in well efficiency. At two locations, the data were unable to provide results that can be interpreted with confidence. As the majority of local groundwater flow occurs through high-permeability open framework gravel lenses, we suggest that reduction in the permeability of these gravels, due to finesediment incursion, is the cause of the reduction in transmissivity and increase in well losses.

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Alkali and alkaline-earth metals

Cited by 6 publications

References 150 publications

2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

Comparison of Decamethyldizincocene [(η⁵-Cp)₂Zn₂] versus Decamethylzincocene [Cp₂Zn] and Diethylzinc Et₂Zn As Precatalysts for the Intermolecular Hydroamination Reaction

Aquifer permeability change caused by a near‐field earthquake, Canterbury, New Zealand

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Alkali and alkaline-earth metals

Cited by 6 publications

References 150 publications

2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

2,5-Bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrolyl Complexes of the Heavy Alkaline Earth Metals: Synthesis, Structures, and Hydroamination Catalysis

Comparison of Decamethyldizincocene [(η5-Cp*)2Zn2] versus Decamethylzincocene [Cp*2Zn] and Diethylzinc Et2Zn As Precatalysts for the Intermolecular Hydroamination Reaction

Aquifer permeability change caused by a near‐field earthquake, Canterbury, New Zealand

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Comparison of Decamethyldizincocene [(η⁵-Cp)₂Zn₂] versus Decamethylzincocene [Cp₂Zn] and Diethylzinc Et₂Zn As Precatalysts for the Intermolecular Hydroamination Reaction