The reaction of 1-nitrobicyclo[n.3.1]alkane-(6 + n)ones with sodium borohydride followed by acidic workup led to ring opening via a one-pot sequence comprising the retro-Dieckmann-type opening of the α-nitroketone structural fragment, followed by aldehyde reduction and a final Nef reaction, leading to highly functionalized 12 to 14-membered carbocyclic ketones bearing three stereocenters, which are adjacent in some of the compounds. The reactions starting from 1-nitrobicyclo[9.3.1]pentadecan-15-ones could be adjusted to give macrocyclic 2,8-dioxabicyclo[3.2.1]octanes containing an additional bridge by diastereoselective formation of a third ring and a fourth stereocenter through acid-promoted intramolecular ketal formation. This is a very interesting ring system related to the core of the zaragozic acid family of natural products.
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http://dx.doi.org/10.1039/c2ob25274k | DOI Listing |
Chem Sci
January 2025
Institute of Chemistry, Academia Sinica 128 Academia Road, Section 2, Nankang Taipei 115201 Taiwan
Nanographenes and polycyclic aromatic hydrocarbons exhibit many intriguing physical properties and have potential applications across a range of scientific fields, including electronics, catalysis, and biomedicine. To accelerate the development of such applications, efficient and reliable methods for accessing functionalized analogs are required. Herein, we report the efficient synthesis of functionalized small nanographenes from readily available iodobiaryl and diarylacetylene derivatives a one-pot, multi-annulation sequence catalyzed by a single palladium catalyst.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8412, Japan.
A one-pot, telescoped transformation of silyl ethers into cyanides that proceeds via silyl-ether oxidation mediated by nitroxyl-radical catalyst and [bis(trifluoroacetoxy)iodo]benzene followed by an imine formation-oxidation sequence using iodine and aqueous ammonia is reported. This transformation is effective for the site-selective transformation of benzylic and allylic silyl ethers in the presence of other silyl ethers. Using an -protected oxime and a catalytic amount of triflic acid instead of iodine/aqueous ammonia is also effective for cyanation.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
A novel PLGA-inspired NP polymerization technique is presented, which allows the formation of NPs via the cross-linking of precisely sequenced short oligolactoglycolic acid dimethacrylates (OLGADMAs). Following the synthesis of a range of OLGADMAs, a library of NPs via this rapid and surfactant-free nanopolymerization method is successfully generated, which permits the simultaneous NP formation and encapsulation of drugs such as dexamethasone. The results indicate that NPs produced through this nanopolymerization technique with precisely controlled sequences exhibit heightened stability compared to conventionally sequenced and non-sequence controlled PLGA, as evidenced by minimal pH changes over five weeks.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, PR China.
D-Allose, a rare sugar, has gained significant attention not only as a low-calorie sweetener but also for its anticancer, antitumor, anti-inflammatory, antioxidant, and other pharmaceutical properties. Despite its potential, achieving high-level biosynthesis of D-allose remains challenging due to inefficient biocatalysts, low conversion rates, and the high cost of substrates. Here, we explored the food-grade coexpression of D-allulose 3-epimerase (Bp-DAE) and L-rhamnose isomerase (BsL-RI) within a single cell using WB800N as the host.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, People's Republic of China; Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, People's Republic of China; Hubei Engineering Center for Infectious Disease Prevention, Control and Treatment, Wuhan, People's Republic of China. Electronic address:
Background: In current years, the CRISPR (clustered regularly interspaced short palindromic repeats) based strategies have emerged as the most promising molecular tool in the field of gene editing, intracellular imaging, transcriptional regulation and biosensing. However, the recent CRISPR-based diagnostic technologies still require the incorporation of other amplification strategies (such as polymerase chain reaction) to improve the cis/trans cleavage activity of Cas12a, which complicates the detection workflow and lack of a uniform compatible system to respond to the target in one pot.
Results: To better fully-functioning CRISPR/Cas12a, we reported a novel technique for straightforward nucleic acid detection by incorporating enzyme-responsive steric hindrance-based branched inhibitors with CRISPR/AsCas12a methodology.
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