24203-50-7Relevant academic research and scientific papers
ETHER DERIVATIVES OF BICYCLIC HETEROARYLS
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Page/Page column 58, (2011/04/18)
The invention relates to compounds of formula (I), wherein the substituents are as defined in the specification; to processes for the preparation of such compounds; pharmaceutical compositions comprising such compounds; such compounds as a medicament; such compounds for the treatment of a proliferative disease
Organocatalysis in a synthetic receptor with an inwardly directed carboxylic acid
Shenoy, Siddhartha R.,Pinacho Crisostomo, Fernando R.,Iwasawa, Tetsuo,Rebek Jr., Julius
, p. 5658 - 5659 (2008/12/21)
A cavitand functionalized with a Kemp-s triacid derivative was used to catalyze the epoxide ring-opening cyclizations of 1,5-epoxyalcohols. A deep, cylindrical cavity containing electron-rich aromatic walls and an inwardly directed carboxylic acid displayed the necessary characteristics to bind different 1,5-epoxyalcohols and initiate their cyclization reactions. The reactions inside this synthetic receptor occurred in a catalytic and regioselective manner. These results highlight that the arrangement of functionality and unique solvation provided by the structured interiors of natural enzymes can be incorporated into synthetic systems having useful physical and chemical properties. Copyright
An Electron Spin Resonance Study of the Regioselectivity of the Cyclization of Protonated and Unprotonated Pent-4-en-1-oxyl and Pent-4-en-1-peroxyl Radicals
Bloodworth, A. J.,Davies, Alwyn G.,Hay-Motherwell, Robyn S.
, p. 575 - 582 (2007/10/02)
The regioselectivity of the ring closure of protonated and unprotonated pent-4-en-1-oxyl radicals has been determined by monitoring by e.s.r. spectroscopy the radicals which are formed when the corresponding pent-4-enyl peroxides (2; R = H or Me) are photolysed in solution.Under neutral conditions, the spectra of the corresponding tetrahydrofuran-2-ylmethyl radicals (6) are observed, confirming the preferential 5-exo-mode of cyclization.When trifluoroacetic acid is present, the different spectra of the protonated tetrahydrofuran-2-ylmethyl radicals (8) are observed, and it is argued that this reflects the similar regioselectivity of the intramolecular addition of the protonated alkoxyl radicals.The identity of the radicals (6) and (8) was confirmed by generating them independently by abstracting bromine atoms from the corresponding bromides (9).Similar experiments with the hydroperoxides (1) failed to show the spectra of the dioxan-3-ylmethyl radicals (17), perhaps because they rapidly undergo γ-scission to the oxygen-centred radicals (18).However, (17) could be trapped with oxygen to afford, after Ph3P reduction, 1,2-dioxanes (4).No evidence could be found for the protonation of alkylperoxyl radicals by trifluoroacetic acid.
