5371-52-8Relevant articles and documents
Dioxygen activation by siloxide complexes of chromium(II) and chromium(IV)
Schax, Fabian,Bill, Eckhard,Herwig, Christian,Limberg, Christian
, p. 12741 - 12745 (2014)
The reaction of a tripodal trisilanol with n-butyllithium and CrCl2 results in a dinuclear CrII complex (1), which is capable of cleaving O2 to yield in a unique complex (2) with an asymmetric diamond core composed of two CrIV=O units. Magnetic susceptibility data reveal significant exchange coupling of CrII (S=2) in 1 and large zero-field splitting for CrIV (S=1) in 2 owing to strong spin-orbit coupling of the ground state. The CrIV=O compound can also be generated using PhIO, and evidence was gathered that although it is the stable product isolated after excessive O2 treatment, it further activates O2 to yield an intermediate species that oxidizes THF or Me-THF. By extensive 18O labeling studies we were able to show, that in the course of this process 18O2 exchanges its label with siloxide O atoms of the ligand via terminal oxido ligands.
Synthesis of functionalized bicyclic imines via intramolecular azide-alkene 1,3-dipolar cycloaddition/intramolecular stork alkylation cascade reaction
De Miguel, Irene,Velado, Marina,Herradon, Bernardo,Mann, Enrique
, p. 1237 - 1242 (2013)
A cascade intramolecular azide-alkene 1,3-dipolar cycloaddition/Stork alkylation reaction has been developed for the synthesis of functionalized cyclic imines with a pyrroline and piperideine structures, employing readily available ω-azidodienes. Copyright
Genotoxicity screening for N-nitroso compounds. Electrochemical and electrochemiluminescent detection of human enzyme-generated DNA damage from N-nitrosopyrrolidine
Krishnan, Sadagopan,Hvastkovs, Eli G.,Bajrami, Besnik,Jansson, Ingela,Schenkman, John B.,Rusling, James F.
, p. 1713 - 1715 (2007)
We report for the first time voltammetric/electrochemiluminescent sensors applied to predict genotoxicity of N-nitroso compounds bioactivated by human cytochrome P450 enzymes. The Royal Society of Chemistry.
Free-radical approaches to stemoamide and analogues
Bogliotti, Nicolas,Dalko, Peter I.,Cossy, Janine
, p. 9528 - 9531 (2006)
(Chemical Equation Presented) Two approaches allowing access to the tricyclic stemona backbone are presented. Both approaches rely on a free-radical cyclization reaction as the key step. In the formal synthesis of (±)-stemoamide, the construction of the A ring of the natural product was achieved via a 5-exo-trig radical cyclization with atom transfer. The two diastereoisomers issuing from this cyclization showed different reactivity while forming the seven-membered ring of the final product. In the second part of this study, a 1-exo-trig free radical cyclization was realized allowing access to the (±)-9,10-bis-epi-stemoamide. This reaction was highly stereoselective and allowed the control of three of the four contiguous stereocenters present in the molecule.
Dual C(sp3)-H Functionalization of Cyclic Ethers via Singlet Oxygen-Mediated Ring Opening and Ring Closing
Yuan, Xu,Yu, Xianglin,He, Kun,Zhang, Ruihan,Xiao, Weilie,Lin, Jun,Zhan, Zhajun,Cheng, Xiaohong,Shao, Zhihui,Jin, Yi
supporting information, p. 8267 - 8272 (2021/10/25)
A metal-free dual C(sp3)-H bond functionalization of saturated cyclic ethers via photooxidative singlet oxygen-mediated ring opening and ring closing has been developed, providing a method for generating hydrobenzofurans/pyrans/dioxins. Mechanistic studies have confirmed that ring-opening intermediates were effectively generated by singlet oxygen-mediated C(sp3)-H activation and efficiently reacted with aldehydes and activated methylene compounds to form a wide array of products with high diastereoselectivities (up to >95:5 dr). This study is a rare example of α,β-dual C(sp3)-H bond functionalization of ethers.
Oxidative Cleavage of Indoles Mediated by Urea Hydrogen Peroxide or H2O2 in Polar Solvents
Llopis, Natalia,Gisbert, Patricia,Baeza, Alejandro
supporting information, p. 3245 - 3249 (2021/06/08)
The oxidative cleavage of indoles (Witkop oxidation) involving the use of H2O2 or urea hydrogen peroxide in combination with a polar solvent has been described. Among these solvents, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) stands out as the one affording the corresponding 2-ketoacetanilides generally in higher yields The protocol described has also enabled the oxidation of different pyrroles and furans derivatives. Furthermore, the procedure was implemented in a larger-scale and HFIP was distilled from the reaction mixture and reused (up to 4 cycles) without a significant detriment in the reaction outcome, which remarks its sustainability and applicability. (Figure presented.).