Comparison of reactivity of phosphagermaallene Tip(t-Bu)Ge=C=PMes* towards sulfur ylides

T.-G. Kocsor (1, 2) , N. Deak (1, 2) , D. Ghereg (1) , G. Nemes (2) , J. Escudie (1) , Heinz Gornitzka (3, 4) , Sonia Ladeira (3, 5) , Arnaud Castel (1)

1 LHFA - Laboratoire Hétérochimie Fondamentale et Appliquée
2 Universitatea Babeş-Bolyai [Cluj-Napoca]
3 LCC - Laboratoire de chimie de coordination
4 UT3 - Université Toulouse III - Paul Sabatier
5 ICT - Institut de Chimie de Toulouse

Phosphagermaallene 1, Tip(t-Bu)GeCPMes* (Tip = 2,4,6-triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl), reacts with diphenylsulfoniumylide (Ph2SCH2) leading to adduct 2, through a nucleophilic attack of the negatively charged carbon atom of the ylide on the positively charged germanium atom followed by a migration of one of the phenyl groups. By contrast, dimethyloxosulfoniummethylide (Me2S(O)CH2) appears much less reactive towards 1: it preferentially undergoes an in-situ oxidation of THF leading to a γ-butyrolactone intermediate which gives a [2+2] cycloaddition by the CO group with the GeC double bond to form 3. The new compounds 2 and 3 were completely characterized by multinuclear NMR spectroscopy and by single crystal X-ray structural analysis.

Domaines: Chimie de coordination

T.-G. Kocsor, N. Deak, D. Ghereg, G. Nemes, J. Escudie, et al.. Comparison of reactivity of phosphagermaallene Tip(t-Bu)Ge=C=PMes* towards sulfur ylides. Journal of Organometallic Chemistry, 2014, 755, pp.120-124. ⟨10.1016/j.jorganchem.2014.01.003⟩. ⟨hal-02007979⟩