58718-53-9Relevant articles and documents
Fungal Dioxygenase AsqJ Is Promiscuous and Bimodal: Substrate-Directed Formation of Quinolones versus Quinazolinones
Einsiedler, Manuel,Jamieson, Cooper S.,Maskeri, Mark A.,Houk, Kendall N.,Gulder, Tobias A. M.
, p. 8297 - 8302 (2021/03/01)
Previous studies showed that the FeII/α-ketoglutarate dependent dioxygenase AsqJ induces a skeletal rearrangement in viridicatin biosynthesis in Aspergillus nidulans, generating a quinolone scaffold from benzo[1,4]diazepine-2,5-dione substrates. We report that AsqJ catalyzes an additional, entirely different reaction, simply by a change in substituent in the benzodiazepinedione substrate. This new mechanism is established by substrate screening, application of functional probes, and computational analysis. AsqJ excises H2CO from the heterocyclic ring structure of suitable benzo[1,4]diazepine-2,5-dione substrates to generate quinazolinones. This novel AsqJ catalysis pathway is governed by a single substituent within the complex substrate. This unique substrate-directed reactivity of AsqJ enables the targeted biocatalytic generation of either quinolones or quinazolinones, two alkaloid frameworks of exceptional biomedical relevance.
Rapid synthesis of 2,3-disubstituted-quinazolin-4-ones enhanced by microwave-assisted decomposition of formamide
Kostakis, Ioannis K.,Elomri, Abdelhakim,Seguin, Elisabeth,Iannelli, Mauro,Besson, Thierry
, p. 6609 - 6613 (2008/03/12)
An efficient methodology for the preparation of a series of 2,3-disubstituted-quinazolin-4(3H)-ones is described via a three step reaction from anthranilic acid. The obtained results also reveal that microwave-assisted rapid decomposition of formamide under controlled conditions of power, temperature and time is a very convenient source of ammonia for the synthesis of 2-substituted-quinazolin-4(3H)-ones and other rings.
Reactions of cyclic β-keto esters and other enol derivatives with 3-acetoxyamino-2-isopropylquinazolin-4(3H)-one: further oxidation of the cyclic α-(3,4-dihydro-2-isopropyl-4-oxoquinazolin-3-yl)amino ketones with lrad tetraacetate leading to ring-expansion (in dichloromethane) and r...
Atkinson, Robert S.,Barker, Emma,Edwards, Paul J.,Thompson, Gordon
, p. 1533 - 1542 (2007/10/02)
The cyclic β-keto esters 12, 20, 22, 26, the β-diketone 28 and enol silyl ethers 24 and 30 have been converted in 60-77percent yields into the corresponding α-(oxoquinazolinyl)amino cyclic ketone derivatives 16, 21, 23, 29, 27, 25 and 31, respectively, by reaction with 3-acetoxyamino-2-isopropylquinatolin-4(3H)-one 11.Further oxidation of some of these products with lead tetraacetate gives products whose nature depends on the solvent used; in dichloromethane, 16, 21 and 25, which contains 5-membered ring ketones, give ring-expanded products 32, 38 and 39, respectively, whereas, in methanol, ring-cleavage of 16, 25 and 27 occurs to give iminoesters 41, 44 and 42/43, respectively.Ring-expansion of 23, 27 and 31, which contain 6-membered ring ketones, does not occur and the only isolated product in each case is the benzoxazinone 40.A mechanism which accounts for this dependence on the solvent is presented: radical intermediates do not appear to be implicated.
