Original 1,4-benzoxazine analogues of ellipticine were prepared using a general synthetic route that relied on an anionic ring annulation as the key transformation. The interest of this approach lies on the possibility of an easy entrance to a wide range of derivatives from the phenol intermediate. In addition, this synthetic strategy offers a smart access to diverse structurally related heteroaryl annulated carbazole analogues of ellipticine just by replacing the starting heterocyclic core. Antiproliferative activities of newly synthesized derivatives were evaluated toward tumor cell lines.

Sigma-1 receptors are involved in numerous pathological dysfunctions and the synthesis of selective ligands is of interest. We identified a fused tetrahydroisoquinoline-hydantoin (Tic-hydantoin) structure with high affinity and selectivity for these receptors. We report here our efforts towards the pharmacomodulation of this substructure, the synthesis of 9 analogs with stereochemistry inversion, opening of isoquinoline ring, removal of isoquinoline nitrogen, replacement of isoquinoline by pyridine, of Tic-hydantoin moiety by quinazolinedione heterocycle. All these analogs provided a loss in the affinity for the sigma-1 receptor. The present work underlines the real importance of the Tic-hydantoin moiety for the obtainment of high affinity ligands.

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Symmetrical and unsymmetrical 2,6-disubstituted dihydropyridines were prepared in high yields under mild conditions using the Suzuki and Stille Pd-catalyzed coupling reactions of imide-derived bisvinyl phosphates with a range of aryl, heteroaryl, and alkenyl moieties. The alkylation reaction at C-4 easily afforded original tri- and tetrasubstituted dihydropyridines. Hydrolysis of the latter under acidic condition provided efficiently either open-chain 1,5-diketones or di- or trisubstituted pyridines.

The Pd-catalyzed functionalization of lactam-derived vinyl phosphates has become an important tool in the last decade for the synthesis of nitrogen-containing heterocycles. By using this method, we were able to introduce alkenyl, aryl and heteroaryl groups on bis-vinylphosphate derivatives to provide efficient access to 2,6-disubstituted 1,4-dihydropyridines.

A simple and efficient protocol for the synthesis of 2,3-disubstituted seven-membered ring ene-carbamates has been developed, based on the first reported carbolithiation of ene-carbamates. (C) 2003 Elsevier Ltd. All rights reserved.