One-Pot Construction of Indolo[2,3-<i>b</i>]quinoxalines through Ruthenium-Catalyzed <i>Ortho</i> C–H Bond Functionalization of 2-Arylquinoxalines with Sulfonyl Azides
N-substituted indolo[2,3-b]quinoxalines has been developed through a Ru(II)-catalyzed ortho C–H functionalization of 2-arylquinoxalines with sulfonyl azides and further oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in one pot. This double C–N bond formation strategy provides a new efficient route for the preparation of a series of biologically relevant 6H-indolo[2,3-b]quinoxaline derivatives in
N-取代的吲哚并[2,3- b ]喹喔啉的合成是通过Ru(II)催化的2-芳基喹喔啉与磺酰叠氮化物的邻位C-H官能化并用2,3-二氯-5进一步氧化而开发的, 6-二氰基-1,4-苯醌一锅。这种双C-N键形成策略为制备一系列生物相关的6 H-吲哚[2,3- b ]喹喔啉衍生物提供了一条新的有效途径,产率高达94%,表明底物适用范围广泛。初步的机理研究表明,连续的 C-N 键形成是通过第一步中五元钌环中间体的形成和第二步中自由基机制的形成进行的。
Quinoxaline Derivatives: Novel and Selective Butyrylcholinesterase Inhibitors
Alzheimer's disease (AD) is a progressive brain disorder which occurs due to lower levels of acetylcholine
(ACh) neurotransmitters, and results in a gradual decline in memory and other cognitive processes. Acetycholinesterase
(AChE) and butyrylcholinesterase (BChE) are considered to be primary regulators of the ACh levels in the brain. Evidence
shows that AChE activity decreases in AD, while activity of BChE does not change or even elevate in advanced
AD, which suggests a key involvement of BChE in ACh hydrolysis during AD symptoms. Therefore, inhibiting the activity
of BChE may be an effective way to control AD associated disorders. In this regard, a series of quinoxaline derivatives
1-17 was synthesized and biologically evaluated against cholinesterases (AChE and BChE) and as well as against α-
chymotrypsin and urease. The compounds 1-17 were found to be selective inhibitors for BChE, as no activity was found
against other enzymes. Among the series, compounds 6 (IC50 = 7.7 ± 1.0 µM) and 7 (IC50 = 9.7 ± 0.9 µM) were found to
be the most active inhibitors against BChE. Their IC50 values are comparable to the standard, galantamine (IC50 = 6.6 ±
0.38 µM). Their considerable BChE inhibitory activity makes them selective candidates for the development of BChE inhibitors.
Structure-activity relationship (SAR) of this new class of selective BChE inhibitors has been discussed.
Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.tetlet.2012.09.045
日期:2012.11
for the selective synthesis of 1,2-disubstitutedbenzimidazoles and quinoxalines in water–methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested
Accessing Quinoxalines by Ring-Opening/Cyclization/Detosylation/Aromatization of Activated Aziridines with 2-Bromoanilines: Synthesis of Tyrphostin AG 1296
作者:Chandan Kumar Shahi、Sajan Pradhan、Aditya Bhattacharyya、Raushan Kumar、Manas K. Ghorai
DOI:10.1002/ejoc.201700506
日期:2017.6.30
Synthesis of substituted 2-arylquinoxalines via an unprecedented Cu(I) catalyzed ring-opening-cyclization followed by detosylation-aromatization of activated aziridines with 2-bromoanilines has been accomplished. The transformation efficiently accommodates a wide range of aziridines and 2-bromoanilines to afford the desired quinoxaline frameworks in excellent yields (up to 86%) as a single regioisomer
The First General, Efficient and Highly Enantioselective Reduction of Quinoxalines and Quinoxalinones
作者:Magnus Rueping、Francisco Tato、Fenja. R. Schoepke
DOI:10.1002/chem.200902907
日期:——
Simple yet efficient: A series of diverse substituted tetrahydroquinoxalines and dihydroquinoxalinones have been synthesized for the first time in a highly enantioselective fashion (see scheme). Using this metal‐free hydrogenation it is possible to isolate these products, which are of high pharmaceutical interest, in good yields and with excellent enantioselectivities in a minimal number of reaction