- Ligand controlled regiodivergent C1 insertion on arynes for construction of phenanthridinone and acridone alkaloids
-
A palladium-catalyzed regiodivergent C1 insertion multicomponent reaction involving aryne, CO, and 2-iodoaniline is established to construct the scaffolds of phenanthridinone and acridone alkaloids. Regioselective control is achieved under the guidance of selective ligands. The phenanthridinones are solely obtained under ligand-free condition. In comparison, application of the electron-abundant bidentate ligand dppm afforded the acridones with high efficiency. The release rate of the aryne from the precursor assists the regioselectivity of insertion as well, which was revealed through interval NMR tracking. A plausible mechanism was suggested based on the control experiments. Representative natural products and two types of natural product analogues were synthesized divergently through this tunable method. Divergent alkaloid synthesis: A multicomponent, regioselective approach for palladium-catalyzed C1 insertion is described. This reaction was applied in the divergent synthesis of phenanthridinone and acridone natural product core scaffolds.
- Feng, Minghao,Tang, Bingqing,Wang, Nengzhong,Xu, Hong-Xi,Jiang, Xuefeng
-
supporting information
p. 14960 - 14964
(2016/02/05)
-
- Metal-free TEMPO-catalyzed oxidative C-C bond formation from Csp 3-H bonds using molecular oxygen as the oxidant
-
An efficient TEMPO-catalyzed oxidative C-C bond formation with two Csp 3-H bonds using molecular oxygen as the oxidant has been developed. The novel transformation provides a new strategy for the TEMPO-O2 catalysis to construct C-C bonds. The advantages of this method include: (1) relatively mild and neutral conditions; (2) simplicity and safety of operation; (3) a stoichiometric amount of dangerous oxidants, any transition metals, additives, even solvent, is not required.
- Zhang, Bo,Cui, Yuxin,Jiao, Ning
-
scheme or table
p. 4498 - 4500
(2012/06/01)
-
- N-substituted phenoxazine and acridone derivatives: Structure-activity relationships of potent P2X4 receptor antagonists
-
P2X4 receptor antagonists have potential as drugs for the treatment of neuropathic pain and neurodegenerative diseases. In the present study the discovery of phenoxazine derivatives as potent P2X4 antagonists is described. N-Substituted phenoxazine and related acridone and benzoxazine derivatives were synthesized and optimized with regard to their potency to inhibit ATP-induced calcium influx in 1321N1 astrocytoma cells stably transfected with the human P2X4 receptor. In addition, species selectivity (rat, mouse, human) and receptor subtype selectivity (versus P2X1,2,3,7) were investigated. The most potent P2X4 antagonist of the present series was N-(benzyloxycarbonyl)phenoxazine (26, PSB-12054) with an IC50 of 0.189 μM and good selectivity versus the other human P2X receptor subtypes. N-(p-Methylphenylsulfonyl)phenoxazine (21, PSB-12062) was identified as a selective P2X4 antagonist that was equally potent in all three species (IC50: 0.928-1.76 μM). The compounds showed an allosteric mechanism of action. The present study represents the first structure-activity relationship analysis of P2X4 antagonists.
- Hernandez-Olmos, Victor,Abdelrahman, Aliaa,El-Tayeb, Ali,Freudendahl, Diana,Weinhausen, Stephanie,Müller, Christa E.
-
supporting information
p. 9576 - 9588
(2013/01/16)
-
- Synthesis and potent antileukemic activities of 10-benzyl-9(10H)-acridinones
-
A novel series of 10-benzyl-9(10H)-acridinones and 1-benzyl-4-piperidones were synthesized and tested for their in vitro antitumor activities against CCRF-CEM cells. Assay-based antiproliferative activity study using CCRF-CEM cell lines revealed that the acridone group and the substitution pattern on the benzene unit had significant effect on cytotoxicity of this series of compounds, among which 10-(3,5-dimethoxy)benzyl-9(10H)-acridinone (3b) was found to be the most active compound with IC50 at about 0.7 μM. Compound 3b was also found to have antiproliferative activity against two other human leukemic cell lines K562 and HL60 using the MTT assay. The antitumor effect of 3b is believed to be due to the induction of apoptosis, which is further confirmed by PI (Propidium iodide) staining and Annexin V-FITC/PI staining assay using flow cytometry analysis.
- Gao, Chunmei,Jiang, Yuyang,Tan, Chunyan,Zu, Xuyu,Liu, Huachen,Cao, Derong
-
p. 8670 - 8675
(2008/12/23)
-