The regioselective cleavage of aryl tosylates by electrochemical reduction
摘要:
The electrochemical reductions of eight bis(tosyloxy)benzanoid compounds were studied as a method for the regioselective cleavage of aryl tosylates. For the methyl bis(tosyloxy)benzoate isomers, a strong preference was observed for cleavage of the tosyl group in conjugation with the electron-withdrawing ester moiety. Thus it was possible to selectively cleave tosyl groups to the ortho or para positions over tosyl groups at the meta positions. The bis(tosyloxy)anisole isomers displayed the opposite regioselectivity favoring cleavage of tosyl groups that were meta to the electron-donating methoxy substituent. The general electrochemical process for the reduction of aryl tosylates has been shown to be selective, high yielding, and reproducible on gram quantities.
A novel pyridinium salt-supported [hydroxy(tosyloxy)iodo]benzene (HTIB) reagent (N-4-[hydroxy(tosyloxy)iodo]phenyl}pyridinium hexafluorophosphate) was prepared via Zincke’s reaction. The conjugate...
The Synthesis of 4-Tosyloxy-2-Substituted Phenols using New Solid Pyridinium Salt Supported [Hydroxyl(Tosyloxy)Iodo]Benzene Reagents
作者:Bing Yang、Jizhen Zhang、Dejian Zhao、Hua Kuang
DOI:10.3184/174751912x13338131755814
日期:2012.5
Two newsolid pyridinium salt supported HTIB reagents (N-4-[hydroxyl(tosyloxy)iodo]benzyl}pyridinium tetrafluoroborate and N-4-[hydroxyl(tosyloxy)iodo]phenylcarbamoylmethyl}pyridinium tetrafluoroborate) were synthesised using a pyridinium salt as a cationic support. Although the former was hygroscopic the latter was stable in air and in a highly humid atmosphere over a few weeks. The latter has an
A novel and convenient approach for tosyloxylation of aromatic ring of some ortho-substituted phenolic compounds using [hydroxy(tosyloxy)iodo]benzene
作者:Om Prakash、Manoj Kumar、Rajesh Kumar
DOI:10.1016/j.tet.2010.05.042
日期:2010.7
substituted monohydric phenols, containing electron-withdrawing substituents at the ortho position to the phenolic group, with [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser’s reagent) leads to novel tosyloxylation of aromaticring, thereby offering a convenient synthesis of hitherto unknown 4-tosyloxy-2-substituted phenols.
The present invention relates to novel compounds that inhibit LRRK2 kinase activity, processes for their preparation, to compositions containing them and to their use in the treatment of diseases characterised by LRRK2 kinase activity, particularly Parkinson's disease and Alzheimer's disease.
The present invention relates to novel compounds that inhibit LRRK2 kinase activity, processes for their preparation, to compositions containing them and to their use in the treatment of diseases characterized by LRRK2 kinase activity, particularly Parkinson's disease and Alzheimer's disease.