28124-19-8Relevant academic research and scientific papers
Synthesis and photochemistry of l,2-digermacyclohexa-3,5-dienes and related compounds
Mochida, Kunio,Akazawa, Miyuki,Goto, Midori,Sekine, Akiko,Ohashi, Yuji,Nakadaira, Yasuhiro
, p. 1782 - 1789 (2008/10/08)
Some new germanium analogues of 1,3-cyclohexadiene, 3,4,5,6-tetraphenyl-, 3,6-diphenyl-, and 3,4,5,6-tetramethyl-l,2-digermacyclohexa-3,5-diene and 3,4,5,6-tetraphenyl-1-germa-2-silacyclohexa-3,5-diene, were prepared and fully characterized by spectroscopic methods. On photolysis, the l,2-digermacyclohexa-3,5-diene underwent extrusion of dialkylgermylene (R2Ge:) to give the corresponding germacyclopentadiene. On irradiation the 1-germa-2-sila-cyclohexa-3,5-diene yielded preferentially the silacyclopentadiene via extrusion of R2Ge:. The mechanism of these photolyses is discussed.
Chemistry of Heavy Carbene Analogues R2M (M = Si, Ge, Sn). 8. Germylenes: Singlets or Triplets? Cheletropic Cycloadditions of Me2Ge and GeI2 to Conjugated Dienes
Schriewer, Michael,Neumann, Wilhelm P.
, p. 897 - 901 (2007/10/02)
Thermally generated germylenes Me2Ge undergo in solution under mild conditions (70-150 deg C) concerted 1,4-additions of the linear cheletropic type to certain 1,3-dienes.Thus, the highly reactive meso diallene 10a gives, in a about 1:1 ratio, only the two isomeric 1-germacyclopentenes 11a and 11b expected from front- and back-side attack of Me2Ge, whereas the D,L-diallene 10b produces only the third isomer, 11c, in accordance with this mechanism.The yields are about 70percent; the isomer purity is >/= 98percent.Likewise, two other E,E-1,4-disubstituted 1,3-butadienes give only the corresponding cis-2,5-disubstituted 1-germacyclopentenes 7a or 9a in 80percent or 30percent yields with an isomer purity of >/= 98percent (limit of the NMR analysis).Similarly, with GeI2 and 10a, only 14a and 14b are found, and 14c with 10b, as expected for a cheletropic reaction.Methylation of 14a-c yields the corresponding compounds 11a-c.Other mechanisms for these 1,4-additions are discussed but are highly unlikely: thermal germylenes Me2Ge and Ge2I behave as singlets.
