923025-63-2Relevant academic research and scientific papers
N-Heterocyclic Carbene Catalyzed (5+1) Annulations Exploiting a Vinyl Dianion Synthon Strategy
Nguyen, Xuan B.,Nakano, Yuji,Duggan, Nisharnthi M.,Scott, Lydia,Breugst, Martin,Lupton, David W.
supporting information, p. 11483 - 11490 (2019/07/18)
Direct polarity inversion of conjugate acceptors provides a valuable entry to homoenolates. N-heterocyclic carbene (NHC) catalyzed reactions, in which β-unsubstituted conjugate acceptors undergo homoenolate formation and C?C bond formation twice, have been developed. Specifically, the all-carbon (5+1) annulations give a range of mono- and bicyclic cyclohexanones (31 examples). In the first family of annulations, β-unsubstituted acrylates tethered to a divinyl ketone undergo cycloisomerization, providing hexahydroindenes and tetralins. In the second, partially untethered substrates undergo an intermolecular (5+1) annulation involving dimerization followed by cycloisomerization. While enantioselectivity was not possible with the former, the latter proved viable, allowing cyclohexanones to be produced with high levels of enantiopurity (most >95:5 e.r.) and exclusive diastereoselectivity (>20:1 d.r.). Derivatizations and mechanistic studies are also reported.
Synthesis, antifungal activity, and structure-activity relationships of coruscanone A analogues
Babu, K. Suresh,Li, Xing-Cong,Jacob, Melissa R.,Zhang, Qifeng,Khan, Shabana I.,Ferreira, Daneel,Clark, Alice M.
, p. 7877 - 7886 (2007/10/03)
Coruscanone A, a plant-derived cyclopentenedione derivative, showed potent in vitro antifungal activity against Candida albicans and Cryptococcus neoformans comparable to amphotericin B and fluconazole. A series of analogues have been synthesized by modification of the cyclopentenedione ring, the enolic methoxy functionality, and the side chain styryl moiety of this natural product lead. A structurally close 1,4-benzoquinone analogue was also prepared. All the compounds were examined for their in vitro activity against major opportunistic fungal pathogens including C. albicans, C. neoformans, and Aspergillus fumigatus and fluconazole-resistant C. albicans strains, with several analogues demonstrating potent antifungal activity. Structure-activity relationship studies indicate that the 2-methoxymethylenecyclopent-4-ene-1,3-dione structural moiety is the pharmacophore responsible for the antifungal activity of this class of compounds while the side chain styryl-like moiety plays an important complementary role, presumably contributing to target binding.
