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[ASAP] Polymersomes: Soft Nanoparticles from Miktoarm Stars for Applications in Drug Delivery
Molecular PharmaceuticsDOI: 10.1021/acs.molpharmaceut.1c00928
Molecular PharmaceuticsDOI: 10.1021/acs.molpharmaceut.1c00928
Bioconjugate ChemistryDOI: 10.1021/acs.bioconjchem.2c00011
Chemical Research in ToxicologyDOI: 10.1021/acs.chemrestox.1c00366
Here we report a microfluidic system for photochemical cycloadditions fabricated using silicon micro processing technologies. The system was optimized to yield residence times of just a few minutes for a range of photochemical [2+2]-cycloaddition reactions facilitated using high power UV-LEDs at 375 nm and triplet photosensitizers, which removed the need for the low wavelengths typically required for these types of transformations. Adducts using different excitable olefins with different linear, carbocyclic, and heterocyclic coupling partners were explored to demonstrate the feasibility of performing photochemistry in microflow in an academic research environment. Finally, a reaction leading to a novel dihydrooxepin-2(3H)-one scaffold and a mechanistic proposal for its formation are reported.
Heteroarenes are important units in organic chemistry and are ubiquitous in natural products, pharmaceuticals, and numerous artificial molecules. Despite great efforts devoted to accessing heteroarenes, the development of new methods to efficiently produce heteroarenes remains a long-term interest. Recently, the strategy of radical-mediated heteroaryl migration has supplied a robust toolkit for the synthesis of a diversity of heteroaryl-containing compounds. This Account summarizes our recent achievements in this field and provides insight into the incorporation of heteroarenes into organic skeletons.1 Introduction2 Radical-Mediated Heteroarylation of Alkanes and Alkenes via Intramolecular Heteroaryl Migration2.1 C(sp3)–H Heteroarylation via Intramolecular Heteroaryl Migration2.2 Difunctionalization of Alkenes via Intramolecular Heteroaryl Migration3 Intermolecular Difunctionalization of Alkenes via ‘Docking-Migration’ Strategy3.1 Sulfone-Based Bifunctional Reagents for Difunctionalization of Alkenes by Docking Migration3.2 Sulfone-Based Reagents for the Synthesis of N-Fused Heteroarenes by Docking Migration3.3 Tertiary Alcohol Based Bifunctional Reagents for Difunctionalization of Alkenes by Docking Migration3.4 Diaryl Ether Based Bifunctional Reagents for Difunctionalization of Alkenes by Docking Migration3.5 Conclusion
A facile approach for the synthesis of benzimidazolones via a Ph3P–I2 promoted reaction of hydroxamic acids is reported. Upon Lossen-type rearrangement of the O-activated hydroxamic acids, the in situ generated isocyanates undergo an intramolecular attack by ortho N-nucleophiles producing the cyclized products in good yields under mild conditions. The method allows the direct preparation of a single regioisomer of N-monosubstituted derivatives using readily accessible starting materials and low-cost reagents with broad substrate scope.
A direct access to O-heterocycles by Bi(OTf)3-catalyzed intermolecular cyclization of phenols with diols is described. Catalytic dehydrative tandem formation of C–O and C–C bonds was achieved by using a Bi(OTf)3 catalyst without any additives. The catalytic intermolecular cyclization of phenols with various diols proceeded to give the corresponding chromanes in up to 91% yield and/or pyran derivatives in up to 66% yield.
Environmental Toxicology and Chemistry, Volume 41, Issue 7, Page 1754-1764, July 2022.