Showing papers by "J. Carlos Menéndez published in 2004"
TL;DR: A new versatile methodology, resulting in a formal three-carbon ring expansion of cyclopentanones, for the efficient assembly of functionalized cyclooctanoids is described.
19 citations
TL;DR: 1,5-Diazaanthraquinone derivatives were synthesized employing single and double hetero Diels-Alder strategies and showed IC(50) values in the 10(-8)M range for human lung carcinoma and human melanoma, which makes them attractive candidates for further development as anticancer agents.
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TL;DR: Microwave irradiation greatly improves the results of cyclocondensation between anthranilic acid and lactim ethers derived from 2,5-piperazinediones in terms of reaction times, yields and stereocenter integrity, leading to pyrazino[2,1-b]quinazoline-3,6-diones as discussed by the authors.
Abstract: Microwave irradiation greatly improves the results of the cyclocondensation between anthranilic acid and lactim ethers derived from 2,5-piperazinediones in terms of reaction times, yields and stereocenter integrity, leading to pyrazino[2,1-b]quinazoline-3,6-diones. The microwave-assisted reaction was also much better than the thermal one when applied to a bis-lactim ether, leading to the corresponding pentacyclic pyrazino [2,1-b:5,4-b']diquinazoline-5,13-dione in excellent yield, and it also improved the preparation of compounds containing the ring system of the anti-MDR natural product N-acetylardeemin.
1 citations
TL;DR: In this article, the treatment of various substituted indoles with 2 equivalents of LDA at 40-45 °C led to their fast and efficient deprotection, and this method was also extended to N-pivaloyl carbazoles and p-carbolines.
Abstract: Treatment of variously substituted indoles with 2 equivalents of LDA at 40-45 °C led to their fast and efficient deprotection. This method was also extended to N-pivaloylcarbazoles and p-carbolines.
1 citations
TL;DR: In this paper, a ring expansion of cyclopentanones for the efficient assembly of functionalized cyclooctanoids is described, based on the chemo-, regio-, and stereoselective alpha,gamma-difunctionalization of beta-ketoesters followed by ring-closing metathesis.
Abstract: [reaction: see text] A new versatile methodology, resulting in a formal three-carbon ring expansion of cyclopentanones, for the efficient assembly of functionalized cyclooctanoids is described. The approach is based on the chemo-, regio-, and stereoselective alpha,gamma-difunctionalization of beta-ketoesters followed by ring-closing metathesis to form functionalized bicyclo[4.2.1]nonanes, precursors of the corresponding cyclooctanes, by selective ring cleavage of the one-carbon-atom bridge.