123347-06-8Relevant academic research and scientific papers
Preparation and structural characterization of 1,4-digerma-2-buten-1,4- diylplatinum(II) complexes and their reactions with alkynes, carbon monoxide, and isocyanides
Mochida, Kunio,Karube, Hironori,Nanjo, Masato,Nakadaira, Yasuhiro
, p. 4734 - 4741 (2008/10/09)
1,4-Digerma-2-buten-1,4-diylplatinum(II) complexes were prepared by treatment of a (η-ethylene)(triphenylphosphine)platinum(0) complex with (Z)-α,β-bis(dialkylgermyl)styrenes, and their structures were determined by spectroscopic analysis coupled with X-ray diffraction methods. Thermolysis of 1,4-digerma-2-buten-1,4-diylplatinum(II) complexes afforded linear and cyclic trigermanes and a dinuclear platinum complex. The 1,4-digerma-2-buten-1,4-diylplatinum(II) complexes reacted with alkynes to give the corresponding insertion products, cyclic germy(germylvinyl)platinum(II) species, whose structures have been determined by spectroscopic analysis. The cyclic germy(germylvinyl)platinum(II) complexes were found to easily liberate 1,4-digermacyclohexa-2,5-dienes and a platinum(O) complex. The reactions of 1,4-digerma-2-buten-1,4-diylplatinum(II) complexes with carbon monoxide and isocyanides afforded the corresponding platinum complexes containing one carbon monoxide and one isocyanide ligand, respectively.
Platinum-catalyzed bis-germylation of alkynes with organodigermanes and cyclic oligogermanes
Mochida, Kunio,Wada, Tohru,Suzuki, Kaoru,Hatanaka, Wakako,Nishiyama, Yuriko,Nanjo, Masato,Sekine, Akiko,Ohashi, Yuji,Sakamoto, Masato,Yamamoto, Akio
, p. 123 - 137 (2007/10/03)
Hexamethyldigermane, Me3GeGeMe3, reacted with various alkynes in the presence of platinum complexes at 120 °C to afford Z-1,2-bis(germyl)ethenes in moderate to good yields. Terminal alkynes exhibit higher reactivities than internal ones. [Pt(acac)2] and [Pt(dba)2] serve as efficient catalysts, while [Pt(PPh3)4], [PtCl2(PPh3)2], and [Pt(dba)2]-phosphite were found to be inactive. Four- and six-membered cyclic oligogermanes, such as dodecamethylcyclohexagermane, (Me2Ge)6, reacted with alkynes in the presence of platinum catalysts to yield 1,4-digermacyclohexa-2,5-dienes in ca. 30% yield. The reactions of phenylacetylene with 1,2-digermacyclohexa-3,5-dienes afforded the corresponding 1,4-digermacycloocta-2,5,7-trienes in 93% yield. Bis(germyl)platinum complexes having various tertiary phosphine ligands have been prepared as models of a key intermediate in the above mentioned catalytic bis-germylation of alkynes, and their structures have been established by spectroscopic methods and X-ray crystallography. Bis(germyl)platinum complexes reacted with phenylacetylene to give the corresponding insertion products, germyl(germylvinyl)platinum species, whose structures have been determined by spectroscopic and X-ray analysis. Germyl(germylvinyl)platinum complexes were found to liberate a bis-germylation product of the alkyne upon heating. The result supports a mechanism involving the oxidative addition of a digermane to a Pt(0) complex, the insertion of an alkyne into one of the two Pt-Ge bonds to give a germyl(germylvinyl)platinum species, and the reductive elimination of the bis-germylation product of the alkyne. Evidence suggesting the extrusion of a germylene unit from the bis-germylplatinum species has been obtained, accounting for the generation courses of other by-products.
Chemistry of heavy carbene analogues R2M (M = Si, Ge, Sn). 16. Reactions of free dimethylgermylene with alkynes and their palladium catalysis
Billeb, Gilbert,Brauer, Hartmut,Neumann, Wilhelm P.,Weisbeck, Markus
, p. 2069 - 2074 (2008/10/08)
Free dimethylgermylene, Me2Ge (1), reacts with alkynes RC≡CR′ (3) to give a multitude of four-, five-, and six-membered germaheterocycles 4-6,8, containing one, two, or even three Ge atoms, or the acyclic 3-germapent-1-en-4-yne 7. The nature of R and R′ (H, alkyl, or aryl) determines whether 1,4-digermacyclohexa-2,5-dienes 4, 1-germacyclopenta-2,4-dienes 6, or 1,2,3-trigermacyclopent-4-ene8 5 are formed. Hexafluoro-2-butyne gives the corresponding 1,2-digermacyclobut-3-ene 8. The mechanisms of product formation are discussed. Germirenes 11 or, in special cases, the digermene Me2Ge=GeMe2 (10) and the cyclotrigermane (Me2Ge)3 (12) are proposed as intermediates. A number of alkynes 3 which do not form isolable products with 1 give compounds 4 or 6 when catalytic amounts of (Ph3P)4Pd are present.
