abstract
a-convenient diastereoselective rearrangement of the racemic (R/S)-spirolchroman-2,4'-imidazolidine]-2',4,5'-triones 3a-c into (2'R,5S)- and (2'S,5R)-5-(3-oxo-2,3-dihydrobenzofuran-2-yl)imidazolidine-2,4-diones 4a-c under alkali conditions is described. The obtained sigma bridged benzofuran-3(2H)-one-hydantoin dyads 4a-c are subsequently transformed into pi conjugated benzofuran-3(2H)-one-hydantoin dyads 5a-c by a diastereoselective dehydrogenation using I-2 (catalytic)/DMSO system to predominantly yield the (Z)-isomer. The novel single and double bonded benzofuran-3(2H)-one-hydantoin conjugate structures 4a-c and 5a-c were unambiguously elucidated by single-crystal X-ray diffraction and 2D NMR techniques allowing an in-depth stereochemical and mechanistic discussions. (C) 2013 Elsevier Ltd. All rights reserved.
keywords
CYCLIN-DEPENDENT KINASES; INDIRUBIN DERIVATIVES; INHIBITORY-ACTIVITIES; CYTOTOXIC AGENTS; HYBRIDS; DESIGN; INDOLE; POTENT
subject category
Chemistry
authors
Talhi, O; Fernandes, JA; Pinto, DCGA; Paz, FAA; Silva, ASM
our authors
Filipe Alexandre Almeida Paz
Principal Researcher
José Alberto Pires Fernandes
Post-doc Fellowshipacknowledgements
We would like to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER, COMPETE, for funding the Organic Chemistry Research Unit (QOPNA) (project PEst-C/QUI/UI0062/2011), Laboratorio Associado Centro de Investigacao em Materiais Ceramicos e Compositos - CICECO (project PEst-C/CTM/LA0011/2011) and the Portuguese National NMR Network (RNRMN). European Community's Seventh Framework Programme (FP7/2007-20139 under grant agreement no 215009) is also acknowledged for financial support. We further wish to thank FCT for the post-doctoral grant SFRH/BD/63736/2009 (to J.A.F.) and for specific funding towards the purchase of the single-crystal X-ray diffractometer.