Cooperation of Cis Vicinal Acceptors for Donor–Acceptor Cyclopropane Activation: TfOH-Promoted Ring-Opening/Aryl Shift Rearrangement to 3- and 5-Ylidenebutenolides
Activation of anti-oxidant Nrf2 signaling by enone analogues of curcumin
摘要:
Inflammation and oxidative stress are common in many chronic diseases. Targeting signaling pathways that contribute to these conditions may have therapeutic potential. The transcription factor Nrf2 is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. Nrf2 is widespread in the CNS and is recognized as an important regulator of brain inflammation. The natural product curcumin exhibits numerous biological activities including ability, to induce the expression of Nrf2-dependent phase II and anti-oxidant enzymes. Curcumin has been examined in a number of clinical studies with limited success, mainly owing to limited bioavailability and rapid metabolism. Enone analogues of curcumin were examined with an Nrf2 reporter assay to identify Nrf2 activators. Analogues were separated into groups with a 7-carbon dienone spacer, as found in curcumin; a 5-carbon enone spacer with and without a ring; and a 3-carbon enone spacer. Activators of Nrf2 were found in all three groups, many of which were more active than curcumin. Dose response studies demonstrated that a range of substituents on the aromatic rings of these enones influenced not only the sensitivity to activation, reflected in EC50 values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2 by these analogues. (C) 2017 Published by Elsevier Masson SAS.
An iridium-catalyzed annulation of chalcones with sulfonylazides via cascade C–H amidation and intramolecular aza-Michael addition was developed, affording a variety of 2-aryl-2,3-dihydro-4-quinolones in moderate to good yields. This reaction features easy operation, readily available starting materials, and the cascade formation of two C–N bonds in one pot.
Trichloroisocyanuric acid mediated one-pot synthesis of 3,5-diarylisoxazoles from <i>α,β</i>-unsaturated ketones
作者:Ashish Bhatt、Rajesh K. Singh、Ravi Kant
DOI:10.1080/00397911.2019.1590848
日期:2019.4.18
Abstract A facile one-pot synthesis of 3,5-diarylisoxazoles from α,β-unsaturatedketones and hydroxylamine hydrochloride is reported. The reaction is efficiently promoted by trichloroisocyanuric acid (TCCA) to afford the desired products, mostly in high yields and in relatively short time. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This
palladium-catalyzed carbonylative Heck reaction of aryl thianthrenium salts with carbon monoxide and alkenes has been developed. This protocol can greatly reduce the quantity of olefins used in the carbonylative Heck reaction. In addition, the reaction can also proceed when the coupling partner is a non-activated olefin which is not common in such carbonylative Heck reactions. Combined with C–H thianthrenation
A metal-free and mild approach for constructing 5-amino-1,2-selenazole skeletons by NBS/KSeCN-mediated N-selenocyanation and nucleophilic cyclization of β-enaminones has been developed. Various isoselenazole compounds and the isoselenazolyl derivatives of anti-inflammatory medicines, including isosepac, oxaprozin, and ibuprofen, have been obtained with good yields. This efficient, “one-pot”, and atomic