994-92-3Relevant academic research and scientific papers
Reactivite de cyclo- et tri-germazanes: Mise en evidence de la participation de germyleneamines dans des reactions d'insertion-elimination
Lacrampe, G.,Lavayssiere, H.,Riviere-Baudet, M.,Satge, J.
, p. 21 - 34 (2007/10/02)
Cyclogermazanes (R2GeNR')n (n=2,3), oligomers of germyleneamines, R2Ge=NR', are obtained through aminolysis or amonolysis of Ge-Cl bonds, by intramolecular transamination, or by reaction between chlorogermanes and dilithium amides.The oligomerization degree (n=2,3) is strongly dependent on the nature of the substituents bonded to nitrogen or germanium.Cleavage reactions by bifunctional protic reagents such as diols, dithiols, aminoalcohols, aminothiols and aminoacids have been studied and lead to the corresponding five-membered germa heterocycles resulting from the cleavage of two consecutive Ge-N bonds.Insertion reactions of either heterocumulenes and insaturated dipoles such as RNCO, RNCS, CO2, CS2, PhCHO or oxirane lead to ring expansion.Compounds resulting from diaddition of isocyanates and isothiocyanates to cyclogermazanes, decompose with formation transient germyleneamines which have been characterized by means of their 1,2-cycloaddition reactions with iso- or isothio-cyanates leading to unsatble diazagermetidiones, (or thiones).Similarly, adducts between cyclogermazanes and aldehydes , CO2, CS2 lead to cyclogermoxanes or cyclogermathianes through the corresponding germanones or germathiones. 1,3-Dipoles such as nitrones react with with cyclogermazanes at temperatures around 150 degree C to give unstable 1,3,5,2-oxadiazagermolidines.The reactivity of cyclogermazanes is enhanced in the presence of triethylamine or hexamethylphosphotriamide.The possibility of participation in the latter reactions for the monomeric germyleneamine R2Ge=NR' resulting from the equilibrium cyclogermazane germyleneamine is discussed.
