59321-65-2Relevant academic research and scientific papers
Synthesis of functionalized benzylsilanes from arylzinc compounds and (iodomethyl)trimethylsilane by means of a novel Rh catalysis
Takahashi, Hideki,Hossain, Kabir M.,Nishihara, Yasushi,Shibata, Takanori,Takagi, Kentaro
, p. 671 - 675 (2007/10/03)
The catalytic activity of a Rh complex in cross-coupling between ArZnI and TMSCH2l was examined in which the Rh complex, generated in situ from [RhCl(1,5-cyclooctadiene)]2 and 1,1′-bis(diphenylphosphino)- ferrocene, exhibited excellent catalytic activity for the production of various functionalized benzylsilanes in good yields. From 31P NMR studies of various solutions containing several of the reaction components, confirmation of the rapid and quantitative transfer of aryl groups from ArZnI to the Rh complex to form arylrhodium species was ascertained. A catalytic cycle, commencing with the transmetalation, was thus proposed for the reaction.
Cleavage of Furan-2-yl, 2-Thienyl-, Benzofuran-2-yl-, and Benzothiophen-2-yl-methyl(trimethyl)silanes (RCH2SiMe3) by Methanolic Sodium Methoxide; Acidities of the Corresponding RCH3 Species
Dembech, Pasquale,Seconi, Giancarlo,Eaborn, Colin,Rodriguez, Juan A.,Stamper, John G.
, p. 197 - 198 (2007/10/02)
Rates of cleavage of RCH2SiMe3 by 2.00M-NaOMe in MeOH or MeOD at 50 deg C have been determined for R = furan-2-yl, 2-thienyl, benzofuran-2-yl, and benzothiophen-2-yl; the values of 1E5ks in MeOH and (in parentheses) in MeOD, where ks is the specific second order rate constant, are, respectively: 0.070 (0.167), 0.26 (0.52), 165 (310), and 70 (130) dm3 mol-1 s-1.The values of the ratios of ks in MeOH to hat in MeOD are in the range 0.42-0.54, consistent with rate-determining separation of the carbanion RCH2-. s is 1.57 (1.55), the ratio is 1.01, consistent with electrophilic assistance by proton transfer from the solvent to the separating carbon centre.> The results are discussed in the light of the deprotonation energies calculated (STO-3G) for the corresponding carbon acids RCH3, and approximate pKa values are derived for the latter, viz. (R =) furan-2-yl, 40.6; 2-thienyl, 39.7; benzofuran-2-yl, 35.2; benzothiophen-2-yl, 35.8.
NICKEL-PHOSPHINE COMPLEX-CATALYZED GRIGNARD COUPLING-II; GRIGNARD COUPLING OF HETEROCYCLIC COMPOUNDS
Tamao, K.,Kodama, S.,Nakajima, I.,Kumada, M.,Minato, A.,Suzuki, K.
, p. 3347 - 3354 (2007/10/02)
A general, versatile method for alkylation and arylation of haloheterocyclic compounds is reported.In the presence of a catalytic quantity of , where dppp stands for Ph2P(CH2)3PPh2, bromothiophenes, halopyridines, haloquinoline, and haloisoquinolines reacted with alkyl and aryl Grignard reagents at room temperature or at ether refluxing temperature to give the cross-coupling products.The coupling reactions has been applied to the synthesis of isoquinoline alkaloids.Reactivities of 2-thienyl and 2-pyridyl Grignard reagents have also been examined.
