Synthesis and chemistry of aryloxygermylene-amine complexes

The synthesis and characterization of dimesityloxygermylene-amine and chloromesityloxygermylene-amine complexes is presented. The versatile reactivity of (MesO) 2Ge–tmeda is reported, especially the cycloaddition with 2,3-dimethyl-1,3-butadiene and dimethyl acetylenedicarboxylate. Mesityloxy groups are revealed to be good ligands for this chemistry and have good potential for further look. The synthesis of stable monomeric dimesityloxygermylene-amine (MesO) 2Ge-NR 3 [NR 3 = Et 2NH, (C 6H 11) 2NH, Et 3N, dabco, tmeda] and chloromesityloxygermylene-amine MesO(Cl)Ge–tmeda complexes is presented. All compounds have been fully characterized by spectroscopic methods. The insertion reaction of (MesO) 2Ge–tmeda 1a with dimethyl disulfide, bis(trimethylsilyl)peroxide and iodomethane is reported. Cycloaddition reactions with dimethylbutadiene are especially effective without any activation and with dimethyl acetylenedicarboxylate led selectively to compounds 7 and 8. In the latter case, the transient formation of a germirene has been evidenced by a trapping reaction. The structures of 3, 7 and 8 were determined by single-crystal X-ray diffraction.