28540-70-7Relevant articles and documents
Chemoselective Hydrogenation of Alkynes to (Z) -Alkenes Using an Air-Stable Base Metal Catalyst
Zubar, Viktoriia,Sklyaruk, Jan,Brzozowska, Aleksandra,Rueping, Magnus
supporting information, p. 5423 - 5428 (2020/07/24)
A highly selective hydrogenation of alkynes using an air-stable and readily available manganese catalyst has been achieved. The reaction proceeds under mild reaction conditions and tolerates various functional groups, resulting in (Z)-alkenes and allylic alcohols in high yields. Mechanistic experiments suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperativity.
Functional group tolerant Kumada-Corriu-Tamao coupling of nonactivated alkyl halides with aryl and heteroaryl nucleophiles: Catalysis by a nickel pincer complex permits the coupling of functionalized Grignard reagents
Vechorkin, Oleg,Proust, Valerie,Hu, Xile
supporting information; experimental part, p. 9756 - 9766 (2011/03/19)
A nickel(II) pincer complex [(MeNN2)NiCl] (1) catalyzes Kumada-Corriu-Tamao cross coupling of nonactivated alkyl halides with aryl and heteroaryl Grignard reagents. The coupling of octyl bromide with phenylmagnesium chloride was used as a test reaction. Using 3 mol % of 1 as the precatalyst and THF as the solvent, and in the presence of a catalytic amount of TMEDA, the coupling product was obtained in a high yield. The reaction conditions could be applied to cross coupling of other primary and secondary alkyl bromides and iodides. The coupling is tolerant to a wide range of functional groups. Therefore, alkyl halides containing ester, amide, ether, thioether, alcohol, pyrrole, indole, furan, nitrile, conjugated enone, and aryl halide moieties were coupled to give high isolated yields of products in which these units stay intact. For the coupling of ester-containing substrates, O-TMEDA is a better additive than TMEDA. The reaction protocol proves to be efficient for the coupling of Knochel-type functionalized Grignard reagents. Thus aryl Grignard reagents containing electron-deficient and/or sensitive ester, nitrile, amide, and CF3 substituents could be successfully coupled to nonactivated and functionalized alkyl iodides. The catalysis is also efficient for the coupling of alkyl iodides with functionalized heteroaryl Grignard reagents, giving rise to pyridine-, thiophene-, pyrazole-, furan-containing molecules with additional functionalities. Concerning the mechanism of the catalysis, [(MeNN2)Ni-(hetero)Ar] was identified as an intermediate, and the activation of alkyl halides was found to take place through a radical-rebound process.
Amino derivatives of phenyl alkyl thiophene as inhibitors of bone resorption. Structure-activity relationship
Wierzbicki, Michel,Boussard, Marie-Francoise,Sauveur, Frederic,Kirsch, Gilbert,Sabatini, Massimo,Lesur, Christophe,Trodjman, Charles,Bonnet, Jacqueline
, p. 840 - 849 (2007/10/03)
Metabolism of arachidonic acid through the 5-lipoxygenase (LO) pathway generates compounds that stimulate osteoclastic bone resorption; since LO metabolites might play a role in bone loss due to excessive resorption it was tried to develop a series of antiresorptive agents starting from an already known LO inhibitor. Of the 35 compounds synthesized, 11 strongly inhibited (10 μmol/l) retinoic acid-induced bone resorption in cultured mouse calvariae; they were also tested for their effect on LO activity using rat peritoneal neutrophils, but no correlation could be drawn between inhibition of LO and bone resorption. Other pathways, still to be identified, must therefore be targeted by these compounds even though LO inhibition might contribute to their effects on bone. Two compounds selected for further studies were found active on parathyroid hormone-induced osteolysis, while they had no effect on basal resorption; they must, therefore, act at some key point in the process of activation of osteoclastic resorption. This series of compounds may represent a new way for the treatment of bone loss due to excessive resorption.
