- PYRAZOLE-OXAZOLIDINONE COMPOUND FOR ANTI-HEPATITIS B VIRUS
-
The present invention discloses a pyrazole-oxazolidinone compound having anti-hepatitis B virus activity, which has the structure of formula (I), wherein each variable is as defined herein.
- -
-
-
- Scope and mechanism of a true organocatalytic beckmann rearrangement with a boronic acid/perfluoropinacol system under ambient conditions
-
Catalytic activation of hydroxyl functionalities is of great interest for the production of pharmaceuticals and commodity chemicals. Here, 2-alkoxycarbonyl- and 2-phenoxycarbonyl-phenylboronic acid were identified as efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. This classical organic reaction provides a unique approach to prepare functionalized amide products that may be difficult to access using traditional amide coupling between carboxylic acids and amines. Using only 5 mol % of boronic acid catalyst and perfluoropinacol as an additive in a polar solvent mixture, the operationally simple protocol features mild conditions, a broad substrate scope, and a high functional group tolerance. A wide variety of diaryl, aryl-alkyl, heteroaryl-alkyl, and dialkyl oximes react under ambient conditions to afford high yields of amide products. Free alcohols, amides, carboxyesters, and many other functionalities are compatible with the reaction conditions. Investigations of the catalytic cycle revealed a novel boron-induced oxime transesterification providing an acyl oxime intermediate involved in a fully catalytic nonself-propagating Beckmann rearrangement mechanism. The acyl oxime intermediate was prepared independently and was subjected to the reaction conditions. It was found to be self-sufficient; it reacts rapidly, unimolecularly without the need for free oxime. A series of control experiments and 18O labeling studies support a true catalytic pathway involving an ionic transition structure with an active and essential role for the boronyl moiety in both steps of transesterification and rearrangement. According to 11B NMR spectroscopic studies, the additive perfluoropinacol provides a transient, electrophilic boronic ester that is thought to serve as an internal Lewis acid to activate the ortho-carboxyester and accelerate the initial, rate-limiting step of transesterification between the precatalyst and the oxime substrate.
- Mo, Xiaobin,Morgan, Timothy D. R.,Ang, Hwee Ting,Hall, Dennis G.
-
supporting information
p. 5264 - 5271
(2018/04/24)
-
- Design and synthesis of isoquinolines and benzimidazoles as RAF kinase inhibitors
-
RAF kinase plays a critical role in the RAF-MEK-ERK signaling pathway and inhibitors of RAF could be of use for the treatment of various cancer types. We have designed potent RAF-1 inhibitors bearing novel bicyclic heterocycles as key structural elements for the interaction with the hinge region. In both series exploration of the SAR was focussed on the substitution of the phenyl ring, which binds to the induced fit pocket. Overall, it was confirmed that incorporation of lipophilic substituents was needed for potent Raf inhibition and a number of potent analogues were obtained.
- Buchstaller, Hans-Peter,Burgdorf, Lars,Finsinger, Dirk,Stieber, Frank,Sirrenberg, Christian,Amendt, Christiane,Grell, Matthias,Zenke, Frank,Krier, Mireille
-
scheme or table
p. 2264 - 2269
(2011/05/15)
-
- BENZIMIDAZOLYL DERIVATIVES
-
The present invention relates to benzimidazolyl derivatives of formula I, the use of the compounds of formula I as inhibitors of one or more kinases, the use of the compounds of formula I for the manufacture of a pharmaceutical composition and a method of treatment, comprising administering said pharmaceutical composition to a patient.
- -
-
Page/Page column 123-124
(2010/02/13)
-
- Design, synthesis and properties of several heterocyclic dopaminergic ligands
-
Two series of non-catechol dopamine (DA) bioisosteres with the hydroxyl groups on the benzene ring replaced by N-H groups were synthesized using phenethylamine as a parent molecule. Compounds from the first series (1-9) contained a primary amine group, wh
- Kostic,Soskic,Joksimovic
-
p. 697 - 702
(2007/10/02)
-