874525-54-9Relevant academic research and scientific papers
Hantzsch Ester-Mediated Photochemical Transformations in the Ketone Series: Remote C(sp3)-H Arylation and Cyclopentene Synthesis through Strain Release
Paternoga, Jan,Kühlborn, Jonas,Rossdam, Nils Ole,Opatz, Till
, p. 3232 - 3248 (2021/02/27)
A metal-free Hantzsch ester-mediated synthesis of cyclopentenylketones as well as O-hetarylketones starting from ketocyclopropanes under eco-friendly conditions was developed. The versatility of the developed conditions is shown by reacting ketocyclopropanes in both a formal [3 + 2] cycloaddition with terminal alkynes (further investigated using theoretical calculations) and a radical C-C-coupling with cyanopyridines. The newly developed methodologies were later on utilized as a downstream reaction for photogenerated cyclopropanes combining UV and visible light photochemistry. Following this procedure, a UV-driven Norrish-Yang-type reaction induces the ring strain of the intermediates, which serves as activation energy for the subsequent ring transformation.
Iron-Catalysed Remote C(sp3)?H Azidation of O-Acyl Oximes and N-Acyloxy Imidates Enabled by 1,5-Hydrogen Atom Transfer of Iminyl and Imidate Radicals: Synthesis of γ-Azido Ketones and β-Azido Alcohols
Torres-Ochoa, Rubén O.,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
supporting information, p. 9477 - 9484 (2019/05/21)
In the presence of a catalytic amount of iron(III) acetylacetonate [Fe(acac)3], the reaction of structurally diverse ketoxime esters with trimethylsilyl azide (TMSN3) afforded γ-azido ketones in good to excellent yields. This unprecedented distal γ-C(sp3)?H bond azidation reaction went through a sequence of reductive generation of an iminyl radical, 1,5-hydrogen atom transfer (1,5-HAT) and iron-mediated redox azido transfer to the translocated carbon radical. TMSN3 served not only as a nitrogen source to functionalise the unactivated C(sp3)?H bond, but also as a reductant to generate the catalytically active FeII species in situ. Based on the same principle, a novel β-C(sp3)?H functionalisation of alcohols via N-acyloxy imidates was subsequently realised, leading, after hydrolysis of the resulting ester, to β-azido alcohols, which are important building blocks in organic and medicinal chemistry.
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.
