The major organogermanium compounds formed by reactions of the dioxane complex of dichlorogermylene with hexamethyldisiloxane, octamethyltrisiloxane, and hexamethyltricyclotrisiloxane are bis(trimethylsiloxy)dichlorogermane, 3,3-dichloro-1,1,1,5,5,7,7,7-octamethyl-3-germa-2,4,6-trioxa-1,5,7-trisilaheptane, and a cyclic germatetrasiloxane. 相似文献
Abstract Insertion of dichlorogermylene (from GcCl2-dioxane) into the P-P bonds of tetraalkyldiphosphanes ((PRR)2 (2a: R, R ? i-Pr; 2b: R? t-Bu, R?i-Pr; 2C; R, R, ?t-Bu) leads 10 dichlorobis(dialkylphosphanyl)germanes 3a-c. With 2a. the insertion remains incomplete: 38 exists in an equilibrium with an adduct of diphosphane 2a with GeCI2, Subsequently 3b and 3c undergo a-climinarions to dialkylchlorophosphanes Sb and Sc and the dimeric phosphanylgermylenes (RR PGeGl)2 4b and 4c [1]. Similar to the above (but in absence of dioxane), reacting the richlorogcrmylphosphane i-Pr(t-Bu)PGeCL3, 7c [2] with the related trichlorosilylphosphanc i-Pr(t-Bu)PSiCl3 provided a mixture of SiCl4, 1c, 3c, 5c and 7c, 3a and 3c have been trapped as inert molybdenum complexes (CO)4 MO(μ-PRR)2 GeGl2 6a and 6c from cquilibrilia conraining la/ 2a/ 3a and 3c/ 4c / 5c / 7c respectively. 相似文献
Reactions of [Ru]Cl ([Ru]={Cp(PPh3)2Ru}; Cp=cyclopentadienyl) with three alkynyl compounds, 1 , 5 , and 8 , each containing a cyclobutyl group, are explored. For 1 , the reaction gives the vinylidene complex 2 , with a cyclobutylidene group, through dehydration at CδH and CγOH. With an additional methylene group, compound 5 reacts with [Ru]Cl to afford the cyclic oxacarbene complex 6 . The reaction proceeds via a vinylidene intermediate followed by an intramolecular cyclization reaction through nucleophilic addition of the hydroxy group onto Cα of the vinylidene ligand. Deprotonation of 2 with NaOMe produces the acetylide complex 3 and alkylations of 3 by allyl iodide, methyl iodide, and ethyl iodoacetate generate 4 a – c , respectively, each with a stable cyclobutyl group. Dehydration of 1 is catalyzed by the cationic ruthenium acetonitrile complex at 70 °C to form the 1,3‐enyne 7 . The epoxidation reaction of the double bond of 7 yields oxirane 8 . Ring expansion of the cyclobutyl group of 8 is readily induced by the acidic salt NH4PF6 to afford the 2‐ethynyl‐substituted cyclopentanone 9 . The same ring expansion is also seen in the reaction of [Ru]Cl with 8 in CH2Cl2, affording the vinylidene complex 10 , which can also be obtained from 9 and [Ru]Cl. However, in MeOH, the same reaction of [Ru]Cl with 8 affords the bicyclic oxacarbene complex 12 a through an additional cyclization reaction. Transformation of 10 into 12 a is readily achieved in MeOH/HBF4, but, in MeOH alone, acetylide complex 11 is produced from 10 . In the absence of MeOH, cyclization of 10 , induced by HBF4, is followed by fluorination to afford complex 13 . Crystal structures of 6 and 12 a ′ were determined by single‐crystal diffraction analysis. 相似文献
Mannich reaction of 1,3-bis[4-(2-mercaptomethylphenoxy)butyl]-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione, formaldehyde, and N-benzylamine afforded a 24-membered macrocyclic compound containing an uracil fragment, 1,3-(11-benzyl-6,7:15,16-dibenzo-5,17-dioxa-9,13-dithia-11-aza-6,15-heneicosadiene-1,21-diyl)-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione. 相似文献
Thermal decarbonylation of 5-aryl-4-phenyl-2,3-dihydrofuran-2,3-diones gives rise to intermediate aroyl(phenyl)ketenes which react with nonactivated Schiff bases, N,N'-dicyclohexylcarbodiimide, and p-di-methylaminobenzonitrile according to the [4 + 2]-cycloaddition pattern with formation of 6-aryl-5-phenyl-4H-1,3-oxazin-4-ones. Reactions of 5-aryl-4-phenyl-2,3-dihydrofuran-2,3-diones with activated Schiff bases at a temperature below the thermolysis temperature lead to 4-aroyl-4-phenyltetrahydropyrrole-2,3-diones. 相似文献
E?Si transfer : Anionic compounds capable of transferring a silicon‐containing double bond are reviewed (see figure), particularly reagents with Si?Si moieties (Tip=2,4,6‐iPr3C6H2, M=Li, Na, K) and their applications towards main‐group and transition‐metal electrophiles, as well as their reactivity towards organic compounds. A few recently reported derivatives with Si?C (Ad=1‐adamantyl) and Si?P moieties are included for completeness.