5267-65-2Relevant articles and documents
Phosphorus-Based Organocatalysis for the Dehydrative Cyclization of N-(2-Hydroxyethyl)amides into 2-Oxazolines
Soleymani Movahed, Farzaneh,Foo, Siong Wan,Mori, Shogo,Ogawa, Saeko,Saito, Susumu
, p. 243 - 257 (2021/12/17)
A metal-free, biomimetic catalytic protocol for the cyclization of N-(2-hydroxyethyl)amides to the corresponding 2-oxazolines (4,5-dihydrooxazoles), promoted by the 1,3,5,2,4,6-triazatriphosphorine (TAP)-derived organocatalyst tris(o-phenylenedioxy)cyclotriphosphazene (TAP-1) has been developed. This approach requires less precatalyst compared to the reported relevant systems, with respect to the phosphorus atom (the maximum turnover number (TON) ～30), and exhibits a broader substrate scope and higher functional-group tolerance, providing the functionalized 2-oxazolines with retention of the configuration at the C(4) stereogenic center of the 2-oxazolines. Widely accessible β-amino alcohols can be used in this approach, and the cyclization of N-(2-hydroxyethyl)amides provides the desired 2-oxazolines in up to 99% yield. The mechanism of the reaction was studied by monitoring the reaction using spectral and analytical methods, whereby an 18O-labeling experiment furnished valuable insights. The initial step involves a stoichiometric reaction between the substrate and TAP-1, which leads to the in situ generation of the catalyst, a catechol cyclic phosphate, as well as to a pyrocatechol phosphate and two possible active intermediates. The dehydrative cyclization was also successfully conducted on the gram scale.
Discovery of a novel cathepsin inhibitor with dual autophagy-inducing and metastasis-inhibiting effects on breast cancer cells
Yuan, Lei,Liu, Jun,He, Wenhui,Bao, Youmei,Sheng, Lei,Zou, Chunyang,Hu, Baichun,Ge, Wentao,Liu, Yang,Wang, Jian,Lin, Bin,Li, Yanchun,Ma, Enlong
, p. 239 - 253 (2018/12/04)
Drug resistance and cancer cells metastasis have been the leading causes of chemotherapy failure and cancer-associated death in breast cancer patients. In present, various active molecules either exhibiting novel mechanism of action such as inducing autophagy or inhibiting metastasis have been developed to address these problems. However, the compounds exhibiting such dual functions have rarely been described. Previous work in our group showed that TSA, as a synthetic analog of asperphenamate, induced autophagic cell death in breast cancer cells instead of apoptosis. Furthermore, the target enzyme of TSA was predicted to be cathepin L (Cat L) by natural product consensus pharmacophore strategy. Accumulated evidences have shown that cathepsins are closely associated with migration and invasion of breast cancer cells. It seemed likely that TSA-like molecules may possess the dual functions of inducing autophagy and inhibiting metastasis. Therefore, sixty optically active derivatives were firstly designed and synthesized by replacing the A-ring moiety of TSA with other substituted-phenyl sulfonyl groups. Further cathepsin inhibitory activity assay showed that (S, S) and (S, R) isomers displayed no activity against four kinds of cathepsins (L, S, K, B), while all derivatives tested were inactive toward K and B subtypes. Compound 6a with meta-bromo substituent displayed the greatest inhibitory activity, and its inhibitory capability against Cat L and S was 3.9 and 11.5-fold more potent than that of TSA, respectively. Molecular docking also exhibited that 6a formed more hydrogen bonds or π-π contacts with Cat L or S than TSA. In order to determine whether 6a could play dual roles, its anti-cancer mechanism was further investigated. On the one hand, MDC staining experiment and western blotting analysis validated that 6a can induce autophagy in MDA-MB-231 cells. On the other hand, its metastatic inhibitory ability was also confirmed by wound healing and transwell chamber experiment.
Synthesis of benzamides through direct condensation of carboxylic acids and amines in the presence of diatomite earth@IL/ZrCl4 under ultrasonic irradiation
Ahmadi, Masoumeh,Moradi, Leila,Sadeghzadeh, Masoud
, p. 7873 - 7889 (2018/09/27)
A green, rapid, mild and highly efficient pathway for the preparation of benzamide derivatives is reported. The reaction was performed through direct condensation of benzoic acids and amines under ultrasonic irradiation in the presence of Lewis acidic ionic liquid immobilized on diatomite earth (diatomite earth@IL/ZrCl4). A new, highly efficient and green solid acid catalyst was easily prepared via a two-step procedure and used as an effective reusable catalyst. The prepared catalyst provides active sites for the synthesis of benzamides. The advantages of this method are the use of a superior and recoverable catalyst, low reaction times, simple procedure, high-yielding and eco-friendly process and use of ultrasonic irradiation as a green and powerful technology. Since benzamides are used widely in the pharmaceutical, paper and plastic industries, and also as an intermediate product in the synthesis of therapeutic agents, the presented new synthetic methods for this type of compounds can be of considerable importance.
Asperphenamate biosynthesis reveals a novel two-module NRPS system to synthesize amino acid esters in fungi
Li, Wei,Fan, Aili,Wang, Long,Zhang, Peng,Liu, Zhiguo,An, Zhiqiang,Yin, Wen-Bing
, p. 2589 - 2594 (2018/03/08)
Amino acid esters are a group of structurally diverse natural products with distinct activities. Some are synthesized through an inter-molecular esterification step catalysed by nonribosomal peptide synthetase (NRPS). In bacteria, the formation of the intra-molecular ester bond is usually catalysed by a thioesterase domain of NRPS. However, the mechanism by which fungal NRPSs perform this process remains unclear. Herein, by targeted gene disruption in Penicillium brevicompactum and heterologous expression in Aspergillus nidulans, we show that two NRPSs, ApmA and ApmB, are sufficient for the synthesis of an amino acid ester, asperphenamate. Using the heterologous expression system, we identified that ApmA, with a reductase domain, rarely generates dipeptidyl alcohol. In contrast, ApmB was determined to not only catalyse inter-molecular ester bond formation but also accept the linear dipeptidyl precursor into the NRPS chain. The mechanism described here provides an approach for the synthesis of new small molecules with NRPS as the catalyst. Our study reveals for the first time a two-module NRPS system for the formation of amino acid esters in nature.
Design, synthesis and biological evaluation of novel asperphenamate derivatives
Liu, Qingyin,Li, Wei,Sheng, Lei,Zou, Chunyang,Sun, Hongxin,Zhang, Chunfeng,Liu, Yang,Shi, Jiyue,Ma, Enlong,Yuan, Lei
, p. 76 - 86 (2016/01/30)
A series of novel asperphenamate derivatives were designed and synthesized, including series I (the A-phenyl group replaced with various aromatic heterocycles) and series II (the acyl group substituted by sulfonyl group). All compounds have been screened for their antiproliferative activity in vitro against MCF-7, HeLa, and BEL-7402 cell lines by the standard MTT method. Structure-activity relationship studies displayed the heterocycle type played an important role in activity. Six-membered ring derivatives displayed more potency than five-membered ring and the sulfonyl group in A-ring region made an important contribution to activity. Among all derivatives, tosyl derivative 8c exhibited the greatest potency in three human cancer cell lines. Especially in MCF-7 cells, the cellular potency of 8c was approximately 3.0-fold more potent than that of cisplatin. Firstly, the mechanism of cell death induced by 8c in MCF-7 cells was investigated. The results showed that the cell death was induced by autophagy instead of apoptosis or cell cycle arrest. Further studies indicated that 8c might induce autophagic cell death in HeLa and BEL-7402 cell lines.
Asymmetric hydroformylation of Z -Enamides and enol esters with rhodium-bisdiazaphos catalysts
Abrams, M. Leigh,Foarta, Floriana,Landis, Clark R.
supporting information, p. 14583 - 14588 (2015/01/08)
Asymmetric hydroformylation (AHF) of Z-enamides and Z-enol esters provides chiral, alpha-functionalized aldehydes with high selectivity and atom economy. Rh-bisdiazaphospholane catalysts enable hydroformylation of these challenging disubstituted substrates under mild reaction conditions and low catalyst loadings. The synthesis of a protected analog of l-DOPA demonstrates the utility of AHF for enantioselective, atom-efficient synthesis of peptide precursors.
Identification, synthesis, and strategy for minimization of potential impurities in the preclinical anti-HBV drug Y101
Hu, Zhanxing,An, Qiao,Li, Kunfeng,Zhang, Yangong,Qiu, Jingying,Xu, Bixue,Pan, Weidong,Cao, Peixue,Liu, Changxiao,Huang, Zhengming,Xia, Wen,Liang, Guangyi
, p. 1156 - 1167 (2013/10/08)
The identification of actual, potential, and theoretical impurities of N-[N-benzoyl-O-(2-dimethylaminoethyl)-l-tyrosyl]-l-phenylalaninol (Y101), a preclinical anti-HBV drug, is described in this article. The impurities were monitored by HPLC, and their structures were established on the basis of NMR, IR, and MS. Most of the impurities were synthesized, and their assigned constitutions were confirmed by HPLC co-injection with an ordinary column (Phenomenex Gemini, 250 mm × 4.6 mm, 5 μm) or a chiral column (DAICEL Chiralcel OD-H). According to the synthetic route, the origins of all of these related impurities were analyzed, and some practical strategies were applied for minimizing these impurities to the level accepted by the International Conference on Harmonization (ICH), and therefore, these strategies can be well applied to the quality control in Y101 clinical sample manufacture.
Synthesis and in vitro antitumor activity of asperphenamate derivatives as autophagy inducer
Yuan, Lei,Li, Yanchun,Zou, Chunyang,Wang, Chao,Gao, Jian,Miao, Caixia,Ma, Enlong,Sun, Tiemin
scheme or table, p. 2216 - 2220 (2012/04/18)
In an effort to improve the aqueous solubility and the antitumor activity of natural product asperphenamate, we have designed and synthesized three series of asperphenamate derivatives, including series I (simplifying molecular skeleton series), series II (introducing a hydroxyl group to A-phenyl ring series) and series III (disrupting molecular planarity series). All derivatives have displayed a significantly increased solubility compared with asperphenamate. Their growth inhibitory activities in vitro were screened by the standard MTT method in MCF-7, HeLa, and BEL-7402 cell lines. With the exception of the derivatives in series I, most of derivatives in series II and series III showed growth inhibitory activity. Among all derivatives, IM23b in series III showed the greatest potency in human breast cancer MCF-7 cells. The cellular potency of IM23b was approximately 1.5-fold more potent than that of cisplatin. The mechanism of cell death induced by IM23b in human breast cancer MCF-7 cells was further investigated. We concluded that the cell death was induced by autophagy instead of apoptosis or cell cycle arrest.
A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: A formal synthesis of (S)-coniine from l-norvaline
Karanfil, Abdullah,Balta, Berrin,Eskici, Mustafa
, p. 10218 - 10229,12 (2020/09/02)
Regioselective ring-opening reactions of a set of representative 1,2-cyclic sulfamidates with lithium triethylorthopropiolate proceeded efficiently to deliver the corresponding δ-amino-α,β-unsaturated esters after acidic hydrolysis. Hydrogenation of the unsaturated esters and subsequent thermal cyclization afforded the related alkyl substituted piperidine-2-ones. This approach represents a novel [3+3] cyclization strategy for the asymmetric synthesis of alkyl substituted piperidin-2-ones. Efficiency of the cyclization process is illustrated by a formal asymmetric synthesis of (S)-coniine from l-norvaline.
Imidazol(in)ium-2-carboxylates as latent, thermally activated organocatalysts for transesterification reactions
Wang, Yanqin,Li, Zhenjiang
experimental part, p. 502 - 507 (2012/07/17)
1,3-Disubstituted imidazol(in)ium-2-carboxylates (ImCO2) were used as precatalysts for transesterification reactions of unactivated ethyl benzoate with monohydric alcohols, dihydric alcohols, and amino alcohols. Highly active N-heterocyclic carbenes (NHCs) are usually not used directly as catalysts because of their air and moisture sensitivity. Here they were liberated in situ by thermal decarboxylation of ImCO2 at designated temperatures. The results showed that the yield of the reactions reached up to 95 within 3 h using only 0.5 mol catalyst. No active enol esters, molecular sieves, or a 20-fold excess of alcohol were used to drive the reaction to completion. It was proved that unsaturated imidazolium-2-carboxylates have a better activity than saturated species in this type of reaction. Different types of substituting groups of ImCO2 exhibited varied transesterification activity.
