64987-77-5Relevant articles and documents
(±)-cis-4a-alkyl-1,3,4,4a,9,9a-hexahydro-2H-carbazol-2-ones by domino nitro reduction-aza-Michael addition to enones
Barrios-Perez, Carlos,Bunce, Richard A.,Embrey, Samuel J.
, (2022/01/11)
A domino nitro reduction-aza-Michael addition sequence has been investigated for α,β-unsaturated ketones and compared with the analogous reaction for conjugated esters. As expected, six-membered ring closures of ketones did not proceed as well as for esters (85%) due to the greater inherent reactivity of the ketones. This problem was minimized by performing the cyclization at lower temperature for a shorter time. The process has been extended to a synthesis of (±)-cis-4a-alkyl-1,3,4,4a,9,9a-hexahydro-2H-carbazol-2-ones with good yields (65%–86%). While the rigidity of the system and closure of the smaller five-membered ring created some strain in the products, yields were acceptable. The cis ring junction resulted from axial attack to give a more stable chair-like enol that tautomerized to the target heterocycle.
Photoresponsive cross-linked polymeric particles for phototriggered burst release
Wang, Zhen,Yu, Lili,Lv, Cong,Wang, Peng,Chen, Yedong,Tang, Xinjing
, p. 552 - 559 (2013/06/26)
We synthesized a series of cross-linked photoresponsive polymeric particles with photolabile monomers and cross-linkers through miniemulsion polymerization. These particles are quite stable in dark, while light irradiation caused the breakage of particles and the efficient release of encapsulated contents up to 95% based on Nile red fluorescence. Photoswitches of particle systems were confirmed by fluorescence spectroscopy, SEM and colorimetry. Particle uptake and triggered release in RAW264.7 cells were confirmed by fluorescein diacetate loaded particles.
Lipase-mediated resolution of substituted 2-aryl-propanols: Application to the enantioselective synthesis of phenolic sesquiterpenes
Serra, Stefano
, p. 619 - 628 (2011/07/08)
A comprehensive study of the lipase-mediated resolution of substituted 2-aryl-propanols is reported. The latter alcohols were submitted to the irreversible acetylation catalyzed either by PPL, CRL, or lipase PS. The enantioselectivity of these transformations was dependent on the type of lipase used. The type of substituents and particularly their position on the aromatic ring strongly affected the selectivity of the reaction. The experiments described prove that PPL is the more versatile lipase catalyzing the acetylation with an enantiomeric ratio (E) value that ranges from 1 up to 144, depending on the substrate used. Conversely, the same transformations were catalyzed by CRL and lipase PS with an enantiomeric ratio value, which is always less than 5. The remarkable behavior of PPL was exploited in the large scale resolution of some substituted 2-aryl-propanols whose enantiomeric forms are relevant building blocks in the enantioselective synthesis of phenolic sesquiterpenes. By these means, the synthesis of (S)-turmeronol B and the formal syntheses of (R)-curcumene, (R)-curcuphenol, (R)-xanthorrhizol, and (R)-curcuhydroquinone were accomplished.
