2749-11-3Relevant articles and documents
Asymmetrical nonbridgehead nitrogen-IV. Chiroptical properties of the amines, N-chloroamines and cyanamides
Kostyanovsky,Gella,Markov,Samojlova
, p. 39 - 45 (1974)
The ORD and CD spectra of 2-methyl-aziridine, azetidine, pyrrolidine, piperidine, their N-Me, N-Hal, N-CN derivatives as well as those of camphidine, N-methyl- and N-cyano-camphidine have been investigated. The possibility of application of the quadrant rule for N-chloroamines is discussed. A similar rule is proposed for the N-CN chromophore.
Calothrixamides A and B from the Cultured Cyanobacterium Calothrix sp. UIC 10520
Crnkovic, Camila M.,Krunic, Aleksej,May, Daniel S.,Wilson, Tyler A.,Kao, Diana,Burdette, Joanna E.,Fuchs, James R.,Oberlies, Nicholas H.,Orjala, Jimmy
, p. 2083 - 2090 (2018)
Cyanobacteria are a source of chemically diverse metabolites with potential medicinal and biotechnological applications. Rapid identification of compounds is central to expedite the natural product discovery process. Mass spectrometry has been shown to be an important tool for dereplication of complex natural product samples. In addition, chromatographic separation and complementary spectroscopic analysis (e.g., UV) can enhance the confidence of the dereplication process. Here, we applied a droplet-liquid microjunction-surface sampling probe (droplet probe) coupled with UPLC-PDA-HRMS-MS/MS to identify two new natural products in situ from the freshwater strain Calothrix sp. UIC 10520. This allowed us to prioritize this strain for chemical investigation based on the presence of new metabolites very early in our discovery process, saving both time and resources. Subsequently, calothrixamides A (1) and B (2) were isolated from large-scale cultures, and the structures were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. The absolute configurations were determined by a combination of chemical degradation reactions, derivatization methods (Mosher's, Marfey's, and phenylglycine methyl ester), and J-based configurational analysis. Calothrixamides showed no cytotoxic activity against the MDA-MB-435, MDA-MB-231, and OVCAR3 cancer cell lines. They represent the first functionalized long-chain fatty acid amides reported from the Calothrix genus and from a freshwater cyanobacterium.
Enabling an atom-economic production of chiral amino alcohols by electrodialysis with bipolar membranes
Cao, Chang-Yan,Chen, Qing,Du, Ming-Gu,Gao, Wei-Ting,Song, Wei-Guo,Zhang, Wei-Ming
, p. 2213 - 2224 (2020)
Optically pure amino alcohols are widely used as essential building blocks of catalysts and auxiliaries in asymmetric synthesis, especially in pharmaceuticals. Catalytic hydrogenation has been regarded as the most effective route to produce chiral amino alcohols, but it is still unsatisfactory, which mainly manifests in the involvement of extra acids and bases, thus generating a large amount of inorganic salt byproducts, along with a relatively low yield. In this paper, we propose a novel approach that integrates catalytic hydrogenation and electrodialysis with bipolar membranes (EDBM) to produce pure chiral amino alcohols in a completely green way. EDBM tackles the sustainability issue by splitting the resulting salt of the hydrogenation into the corresponding acid and base (amino alcohol solutions), and the acid could be reused in the next batch directly and a closed loop forms. Here, as a model system to demonstrate the feasibility, a biorenewable chiral l-alanine solid and clean H2 gas are used as the feed stocks and finally converted into a pure l-alaninol product successfully, with no discharge of harmful substances. Furthermore, three typical mineral acids (H3PO4, H2SO4 and HCl) have been investigated systematically and achieved similar performances. The results of all tests and the cost analysis strongly suggest that this new approach is widely applicable, highly productive and sustainable. It demonstrates a true atomically economic route to produce chiral amino alcohols and entirely meets the requirements of green chemistry.
Reduction of silyl esters of amino acids.
Venkateswaran,Bardos
, p. 1256 - 1259 (1967)
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Expansion of substrate scope for nitroxyl radical/copper-catalyzed aerobic oxidation of primary alcohols: A guideline for catalyst selection
Iwabuchi, Yoshiharu,Nagasawa, Shota,Sasaki, Ryota,Sasano, Yusuke,Yamaichi, Aoto
, p. 488 - 497 (2021/05/27)
Four distinctive sets of optimum nitroxyl radical/copper salt/additive catalyst combinations have been identified for accommodating the aerobic oxidation of various types of primary alcohols to their corresponding aldehydes. Interestingly, less nucleophilic catalysts exhibited higher catalytic activities for the oxidation of particular primary allylic and propargylic alcohols to give α,β-unsaturated aldehydes that function as competent Michael acceptors. The optimum conditions identified herein were successful in the oxidation of various types of primary alcohols, including unprotected amino alcohols and divalent-sulfur-containing alcohols in good-to-high yields. Moreover, N-protected alaninol, an inefficient substrate in the nitroxyl radical/ copper-catalyzed aerobic oxidation, was oxidized in good yield. On the basis of the optimization results, a guideline for catalyst selection has been established.
Selective hydrogenation of primary amides and cyclic di-peptides under Ru-catalysis
Subaramanian, Murugan,Sivakumar, Ganesan,Babu, Jessin K.,Balaraman, Ekambaram
supporting information, p. 12411 - 12414 (2020/10/30)
A ruthenium(II)-catalyzed selective hydrogenation of challenging primary amides and cyclic di-peptides to their corresponding primary alcohols and amino alcohols, respectively, is reported. The hydrogenation reaction operates under mild and eco-benign conditions and can be scaled-up.