- Synthesis of o-Aminophenols via a Formal Insertion Reaction of Arynes into Hydroxyindolinones
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A novel approach toward the synthesis of sterically hindered o-aminophenols has been achieved by a formal aryne insertion into hydroxyindolinones. This transformation offers a rapid and efficient entry to diverse o-aminophenol scaffolds under mild transit
- Chen, Zhilong,Wang, Qiu
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- An axial-to-axial chirality transfer strategy for atroposelective construction of C–N axial chirality
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C–N axially chiral skeletons are ubiquitous in bioactive natural products, pharmaceuticals, and chiral ligands. However, their atroposelective synthesis remains a formidable challenge because of their innate low configurational stability compared with tha
- Chen, Jiangwei,Cheng, Hong-Gang,Hong, Xin,Hua, Yu,Liu, Ze-Shui,Ma, Yuanyuan,Wu, Chenggui,Xie, Pei-Pei,Zhou, Qianghui
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supporting information
p. 1917 - 1932
(2021/05/31)
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- Design, synthesis and biological evaluation of novel human monoamine oxidase B inhibitors based on a fragment in an X-ray crystal structure
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Herein we report our efforts of developing reversible selective hMAO-B inhibitors based on isatin, a fragment in an X-ray crystal structure. Five different scaffolds were designed and many compounds were synthesized. Among them, compound A3 demonstrated very high potency and isoform selectivity against hMAO-B, 11 and 13 times more potent (IC50 = 3 nM) and 23.64 and 6.8 times more selective than the marked drugs, selegiline and safinamide. However, the endeavors to modify the polar 3-one group of isatin, that is in a hydrophobic environment in the binding site of hMAO-B, to small nonpolar hydrophobic groups did not bring about improved hMAO-B inhibitors, which may challenge our understanding of molecular interactions and molecular recognition in biological systems.
- Cheng, Kai,Li, Shiyu,Lv, Xiao,Tian, Yongbin,Kong, Haiyan,Huang, Xufeng,Duan, Yajun,Han, Jihong,Xie, Zhouling,Liao, Chenzhong
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supporting information
p. 1012 - 1018
(2019/02/24)
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- The 2,2-Dimethyl-2-(ortho-nitrophenyl)acetyl (DMNPA) Group: A Novel Protecting Group in Carbohydrate Chemistry
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The 2,2-dimethyl-2-(ortho-nitrophenyl)acetyl (DMNPA) group was introduced to synthetic carbohydrate chemistry as a protecting group (PG) for the first time. Benefiting from a unique chemical structure and novel deprotection conditions, the DMNPA group can be cleaved rapidly and mutually orthogonal to other PGs. Orchestrated application of the DMNPA group with other PGs led to the highly efficient synthesis of the glycan of thornasterside A.
- Liu, Hui,Zhou, Si-Yu,Wen, Guo-En,Liu, Xu-Xue,Liu, De-Yong,Zhang, Qing-Ju,Schmidt, Richard R.,Sun, Jian-Song
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supporting information
p. 8049 - 8052
(2019/10/11)
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- Method for preparing and removing saccharide hydroxyl protecting group dimethyl phenylacetyl DMNA
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The invention relates to a method for preparing and removing saccharide hydroxyl protecting group dimethyl phenylacetyl DMNA. The method comprises the following steps: (1) efficiently introducing saccharide hydroxyl protecting group dimethyl phenylacetyl into saccharide hydroxyl; and (2) efficiently removing a hydroxyl protecting group shown in the description. The method is environmentally friendly and has the advantages that the advantages that the preparation is simple, the introduction is efficient, the operation is easy, the removal is efficient, and the application range is wide; and furthermore, a protecting group has very good stereoselectivity when being used for protecting 2-hydroxyl of a glycosyl donor, so that the development and application of the protecting group are promoted.
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Paragraph 0016; 0017; 0018; 0020
(2017/08/29)
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- Cu-Catalyzed Intramolecular Amidation of Unactivated C(sp3)-H Bonds to Synthesize N-Substituted Indolines
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A copper-catalyzed intramolecular amidation of unactivated C(sp3)-H bonds to construct indoline derivatives has been developed. Such an amidation proceeded well at primary C-H bonds preferred to secondary C-H bonds. The transformation owned a b
- Pan, Fei,Wu, Bin,Shi, Zhang-Jie
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supporting information
p. 6487 - 6490
(2016/05/02)
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- Azo-reductase activated budesodine prodrugs for colon targeting
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Budesodine is a synthetic glurocorticoid that undergoes substantial first pass metabolism, limiting systemic exposure. Its use in treatment of inflammatory bowel disease would benefit from a targeting strategy that could lead to a local topical effect, improving safety and increasing anti-inflammatory efficacy. A two-step prodrug strategy involving azoreduction/cyclization that we developed previously for prednisolone is here applied with some variations to budesonide. The budesodine prodrugs were tested using an in vitro azoreductase assay simulating human colonic microflora. The kinetics of amino steroid ester cyclization and its pH dependence was also evaluated. The stability of the prodrugs systems in simulated human duodenal and gastric fluid was evaluated to determine the likelihood of intact intestinal transit. The propionic acid derived prodrug 3 undergoes rapid activation by Clostridium perfingens and its putative reduction product cyclizes with acceptable rapidity when synthesized independently. These properties of 3 suggest that it has potential in management of ulcerative colitis.
- Marquez Ruiz, Juan F.,Kedziora, Kinga,O'Reilly, Mary,Maguire, Jacqueline,Keogh, Brian,Windle, Henry,Kelleher, Dermot P.,Gilmer, John F.
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p. 7573 - 7577
(2013/02/23)
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- PYRROLO[2,3-D]PYRIMIDINE DERIVATIVES AS CGRP RECEPTOR ANTAGONISTS
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The present invention relates to novel compounds that are CGRP receptor antagonists, processes for their preparation, to compositions containing them and to their use in the treatment of migraine, headache, and cluster headache.
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Page/Page column 51
(2009/07/25)
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- 5′-(2-Nitrophenylalkanoyl)-2′-deoxy-5-fluorouridines as potential prodrugs of FUDR for reductive activation
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Four 5′-(2-nitrophenylalkanoyl)-2′-deoxy-5-fluorouridines (1a-d) were designed and synthesized as potential prodrugs of FUDR for reductive activation. Two methyl groups were introduced α to the ester carbonyl to increase both the rate of cyclization activation and the stability of the conjugates towards serum esterases. Chemical reduction of the nitro group into an amino leads to cyclization and release of the active FUDR. Kinetic analysis of the cyclization activation process indicates that the two methyl groups α to the ester carbonyl restrict the rotational freedom of ground state molecule and promote the cyclization reaction. However, the two methyl groups also were found to render the conjugates as poor substrates of E. coli B nitroreductase. Conjugate 1c, without the two methyl groups, was reduced by E. coli B nitroreductase (t1/2=8 h) to give two products, a N-hydroxyl lactam and the drug FUDR, suggesting that the enzymatic reduction and subsequent cyclization activation proceeded through the hydroxylamine intermediate. These results indicate that cyclization activation will occur once the nitro group is reduced either to an amino or to a hydroxylamino group. The fact that the amino intermediates cyclized easily to release the incorporated drug FUDR suggests the feasibility of using peptide-linked acyl 2-aminophenylalkanoic acid esters as potential prodrugs for proteolytic activation.
- Liu, Bin,Hu, Longqin
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p. 3889 - 3899
(2007/10/03)
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- 5'-[2-(2-Nitrophenyl)-2-methylpropionyl]-2'-deoxy-5-fluorouridine as a potential bioreductively activated prodrug of FUDR: Synthesis, stability and reductive activation
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5'-[2-(2-Nitrophenyl)-2-methylpropionyl]-2'-deoxy-5-fluorouridine was synthesized as a potential bioreductively activated prodrug of 5-fluoro-2'-deoxyuridine (FUDR). The target compound was stable in both phosphate buffer and human serum and was found to
- Hu, Longqin,Liu, Bin,Hacking, Douglas R.
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p. 797 - 800
(2007/10/03)
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