78100-52-4Relevant academic research and scientific papers
Etude comparative des reactions par transfert monoelectronique entre les germylamines primaires, secondaires et tertiaires et la 3,5-di-tert-butylorthoquinone
Riviere-Baudet, Monique,Morere, Alain,Khallaayoun, Abdelhay
, p. 43 - 49 (2007/10/02)
Several germylamines were treated with 3,5-di-t-butylorthoquinone (1).Competitive 1,2 and 1,4 additions resulted using the tertiary amine Et3GeNPh2.The thermally unstable 1,4 adduct gives 2,2-dialkyl-4,5-(6,8-di-t-butyl)benzo-2-germa-1,3-dioxolanne.The 1,2 adduct leads via intermolecular redistribution to bis(triethylgermyl)oxide ((Et3Ge)2O), and aminal with partial regeneration of the initial quinone.These reations seem to proceed solely via a mono-electron transfer mechanism; the aminyl radical Ph2N and the transitory o-semiquinonic germylated radical formed in the reaction have been characterized by ESR spectroscopy.The o-semiquinonic radical then gives O-germyl-3,5-di-t-butylcatechol by hydrogen abstraction.As ethylene and isobutene have been characterized, these hydrogen abstractions occur from ethyl groups linked to germanium and from t-butyl groups belonging to the organic moieties.In the reaction of the secondary amine Et3GeN(H)Ph, a germylaminyl radical is mainly formed instead of an o-semiquinonic germylated radical, which can explain the lesser amount of germadioxolanne obtained.The quinone 1 is partially transformed in o-diphenol under the action of Mes3GeNH2.No germylated adducts are observed.Aminyl radicals characterized in several reactions between germylamines and 1 were also obtained via monoelectronic transfer between lithium amids and tri-t-butylnitrozobenzene (BNB), thus providing a new, useful method for obtaining such species.
Addition 1,4 de divers organo- et organohalogeno-hydrogermanes sur la di-t-butyl-3,5 orthoquinone
Riviere, P.,Castel, A.,Satge, J.,Guyot, D.,Ko, Y. H.
, p. 51 - 60 (2007/10/02)
The thermal 1,4-addition of triorganohydrogermanes R3GeH(R=Et, Ph) with 3,5-di-t-butylorthoquinone leads to their corresponding mono-O-germylated catechols in good yields.Similarly, the organohalohydrogermanes give the 2,2-di-organo- (or 2,2-organohalo)(6,8-di-t-butyl)-4,5-benzo-2-germa-1,3-dioxolanes after dehydrochlorination of transient mono-O-chlorogermylated catechols.Since these reactions are only slightly dependent on solvent and radical initiators, the mechanism probably involves monoelectronic transfer with the formation of a radical anion pair in the first step.The ESR measurements show the transient formation of a paramagnetico-semiquinonic species which supports the proposed mechanism.
Reaction de derives a liaison germanium-azote (germylamines, cyclogermazanes et germa-imines transitoires) avec la di-t-butyl-3,5-orthoquinone
Riviere-Baudet, M.,Riviere, P.,Khallaayoun, A.,Satge, J.,Rauzy, K.
, p. 77 - 94 (2007/10/02)
Several germanium-nitrogen compounds were treated with 3,5-di-t-butylorthoquinone (1).In the case of germylamines R3GeNMe2 (R = Et, Ph), 1,2 and 1,4 adducts were formed, as shown by 1H NMR spectroscopy.The thermally unstable 1,4 adduct, decomposes with nitrene elimination to give 2,2-dialkyl or 2,2-diaryl (6,8-di-t-butyl)-4,5-benzo-2-germa-1,3-dioxolane.The 1,2 adduct, through intermolecular redistribution, leads to digermyloxide (R3Ge)2O and a gem-diamine with partial regeneration of the starting quinone 1.These addition reactions proceed through a monoelectric transfer mechanism, with formation of a transient o-semiquinonic radical identified by ESR spectroscopy.This transient radical leads to O-germyl 3,5-di-t-butylcatechol by hydrogen abstraction from the solvent.The proposed mechanism explains the formation of the germylated compounds as well as the organic by-products.Similar reactions were observed between cyclodigermazanes and 1.The 1,4 cycloaddition generates germadioxolanes with nitrene expulsion, whereas the 1,2-cycloaddition leads to the germoxane and conjugated ketoimine, or diimine.The latter is a good trapping agent for the nitrene formed in the decomposition of the 1,4 adduct.Both the 1,4 and 1,2 cycloadduct decompositions imply transient germaimine formation.The same germaimine, formed at room temperature from intramolecular dehydrogenation of the hindered R2ClGeNHR' by 1,8-diazabicyclo-7-undecene) gives the same reaction products.
Cycloaddition of Germylenes to 3,5-Di-t-butylorthoquinone
Riviere, Pierre,Castel, Annie,Satge, Jacques,Guyot, Daniel
, p. 157 - 164 (2007/10/02)
The germylenes X2Ge, RGeX and R2Ge (X= halogen, OR; R= alkyl or aryl) react at room temperature with 3,5-di-t-butyl orthoquinone by regioselective cycloaddition.The corresponding substituted 2-germa-1,3-dioxolans are formed similarly in good yields, but t
