Synthesis and Photochemistry of 1,2-Digermacyclohexa-3,5-dienes and Related Compounds

Abstract

Some new germanium analogues of 1,3-cyclohexadiene, 3,4,5,6-tetraphenyl-, 3,6-diphenyl-, and 3,4,5,6-tetramethyl-1,2-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 1,2-digermacyclohexa-3,5-diene underwent extrusion of dialkylgermylene (R2Ge:) to give the corresponding germacyclopentadiene. On irradiation the 1-germa-2-silacyclohexa-3,5-diene yielded preferentially the silacyclopentadiene via extrusion of R2Ge:. The mechanism of these photolyses is discussed.

Structure of Diels-Alder adduct of phenylated germole and 1,4-epoxy-1,4-dihydronaphthalene revisited

“…Synthesis of 5 was carried out under high pressure in dichloromethane by reaction of 1,1-dimethyl-2,3,4,5-tetraphenyl-1-germa-2,4-cyclopentadiene 4 [6] with 6,7-dibromo-1,4-epoxy-1,4-dihydronaphthalene 3…”

“…The 1,1-dimethyl-2,3,4,5-tetraphenyl-1-germa-2,4-cyclopentadiene (4) [6] and dibromide (3) [7] were prepared by literature methods. 1H and 13C NMR spectra were recorded in CDCl 3 solutions containing tetramethylsilane as internal standard on a Bruker Avance 300 NMR spectrometer fitted with a gradient probe.…”

High‐Pressure Assisted Synthesis of Fused Norbornenes Containing Two7‐Metallonorbornene Units

“…Dry THF used in air-sensitive experiments was dried and distilled from sodium/calcium hydride under nitrogen prior to use. The 1,1-dimethyl-2,3,4,5-tetraphenyl-1-silacyclopenta-2,4-diene (1), [28] 1,1-dimethyl-2,5-diphenyl-1-silacyclopenta-2,4-diene (2) [29] and 1,1-dimethyl-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene (3) [30] were prepared according to the literature. Compounds 4 [31] and 5 [32] were available from our previous work.…”

Organodilithium Intermediates as Useful Dianionic Synthons: Recent Advances

“…The reaction of compound 283 with gallium trichloride yielded the aniocic compound 284, so representing the first synthesis of a spirogallane (Scheme 60) [123]. Meanwhile, different 1,2-digerma-and 1,2-germasila-3,5-cyclohexadienes 285 were prepared and fully characterized by reaction of the intermediate 283 with appropriate digermaand germasilachlorides (Scheme 60) [124]. A severely twisted In2C8 ten-membered ring system 286 was obtained upon reaction of compound 283 with indium tribromide, the tetraphenylbutadienyl units being bridged by two indium atoms in its structure (Scheme 60) [125].…”