23932-77-6Relevant articles and documents
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.
TRIMESITYLGERMYLAMINE Mes3GeNH2: SYNTHESES, STRUCTURE, PROPRIETES
Riviere-Baudet, Monique,Morere, Alain,Onyszchuk, Mario,Satge, Jacques
, p. 75 - 90 (2007/10/02)
Sterically hindered trimesitylgermylamine is a rare example of a stable primary germylamine.X-ray structural data show that germanium is shielded from nucleophilic attack by the surrounding mesityl groups.Nitrogen is still accessible, and the only reactions which occur are those in which the first step of the transition state proceeds through an electrophilic attack on nitrogen.With acid chlorides, Mes3GeNH2 reacts mainly as a primary amine forming the corresponding N-germylamides.The primary amine behaviour is also evident in the reaction with aldehydes.However, functional hydrogen cannot be substituted by lithium, probably because of steric hindrance which prevents the approach of an organolithium derivative.Insertion reactions into the Ge-N bond are difficult.Carbon dioxide and disulfide react only upon heating and yield trimesitylgermyliso- or isothiocyanates (Mes3GeN=C=X; X = O, S) through thermal degradation of the carbamate or dithiocarbamate initially formed. 3,5-di-tert-butylorthoquinone does not form an adduct with Mes3GeNH2, but is slowly transformed into 3,5-di-tert-butylorthocatechol.In spite of its steric hindrance, the trimesitylgermylamino group failed to stabilize a N-germylated germa-imine since the precursor Mes3Ge(Cl)NH-GeMes3 is not stable and gave cyclodigermazane (Mes2GeNH)2 and trimesitylgermyl chloride through Ge-Cl/Ge-N exchange reactions. Key words: Trimesitylgermylamine; 4-methyl 1-trimesitylgermoxy-benzene; N-trimesitylgermyl 2,2-dimethylpropanamide; trimesitylgermylisocyanate; trimesitylgermylisothiocyanate; tetramesitylcyclodigermazane.
Trimesitylgermyllithium: synthese et reactivite
Castel, A.,Riviere, P.,Satge, J.,Ko, Y.H.,Desor, D.
, p. 7 - 15 (2007/10/02)
The new organogermyllithium Mes3GeLi has been prepared in good yield by hydrogermolysis reaction of t-butyllithium in THF.The bulky group favours stabilization in the form of the THF complex.Mes3GeLi has been characterized by alkylation reaction with MeI.
