Alkaline-earth-metal arenesulfonates as precursors to organic derivatives of Group 2 metals

Bis(trimethylsilyl)methyl Derivatives of Calcium, Strontium and Barium: Potentially Useful Dialkyls of the Heavy Alkaline Earth Elements

“…Subsequent to the description of V, Lappert reported that reactions of either [Ca{OSO 2 C 6 H 4 -4-Me} 2 ] in THF or CaI 2 in benzene with potassium bis(trimethylsilyl)methanide gave the calciate species K[Ca{CHA C H T U N G T R E N N U N G (SiMe 3 ) 2 } 3 ], irrespective of reaction stoichiometry. [11,12] Westerhausen also demonstrated that reaction of Ca metal and [Sn{CHA C H T U N G T R E N N U N G (SiMe 3 ) 2 } 2 ] in toluene/DME provided the calcium stannanide Ca[Sn{CH-…”

“…have been identified spectroscopically, [11] to the best of our knowledge, the only previous complex with a Sr À C alkyl s bond to have been structurally [14] which utilised an extremely sterically demanding tris(organosilyl)methyl ligand with an additional O-donor functionality within the periphery of the silicon-stabilised carbanion. Although the isolated crystalline compound displayed a tendency to undergo loss of THF, and an integration of the 1 H NMR spectral data indicated a bis-THF-adducted complex similar to that observed within the structure of 1, a further X-ray analysis revealed that strontium dialkyl 2 crystallises with an additional molecule of donor solvent to form the five-coordinate complex illustrated in Figure 2.…”

Aktivierung einer an Zink gebundenen Ethylgruppe durch Bildung eines Zn‐CEt‐Ba‐Fragments und Kristallstruktur von [((Me3Si)2N)Ba(thf)Zn2(μ‐Et)(μ3‐PSitBu3)2]2 mit verbrückenden Ethyl‐Substituenten

“…In den letzten Jahrzehnten wurden mehrere Herstellungsmethoden entwickelt, um s-gebundene Alkylbarium-Verbindungen zu synthetisieren, [2] und die meisten dieser Derivate enthalten a-gebundene Aryl- [3] und Trialkylsilyl-Gruppen. [4] Diese Verbindungen fanden breite Anwendung als Polymerisationsinitiatoren, [5] ihre Strukturen konnten aber erst in jüngster Zeit bestimmt werden. [6,7] Um Nebenreaktionen zu vermeiden, tragen die Substituenten keine b-Wasserstoffatome.…”

Formation of Calcium–Carbon Bonds From a Lewis Acid-Base Reaction of Calcium Bis[bis(trimethylsilyl)amide] and Tris(trimethylsilylmethyl)alane

“…Wells and co-workers [16] previously deduced the dimeric nature of 3 from NMR spectroscopic data. The Al1ϪP1 bond length of 248.0(1) pm is shorter than the AlϪP distance of the adduct (Me 3 SiCH 2 ) 3 AlϪP(SiMe 3 ) 3 [268.1(4) pm [16] ] but in the same range as for (Me 3 SiCH 2 ) 2 Al(Br)ϪP(SiMe 3 ) 3 [249.8(7) pm [16] ] and in the dimer [(Me 3 SiCH 2 )Al(Br)Ϫ P(SiMe 3 ) 2 ] 2 [243.6(2) pm [16] ] with four-coordinate aluminium and phosphorus atoms. In comparison with the dimer with ethyl groups at the aluminium atom, the endocyclic bond lengths in 3 are elongated and a slight distortion is observed {[Et 2 AlϪP(SiMe 3 The molecular structure of compound 4 is represented in Figure 4.…”

“…The metathesis reaction of KC(SiMe 3 ) 3 and calcium diiodide gave compound B. The reaction of alkaline earth metal arenesulfonates with bis(trimethylsilyl)methyl lithium or potassium yields alkali metal [tris(alkyl)alkaline earth metalates] C. [3] The metalation reaction is only applicable to organic substrates with acidic hydrogen atoms such as phenylacetylene as shown by Burkey and Hanusa [4] for the synthesis of [(η 5 -iPr 4 C 5 H)CaϪCϵCϪPh] 2 (D). The crown ether complexes of the heavier alkaline earth metal bis(triphenylsilylacetylides) E display bent MϪCϵC fragments.…”