INFLUENCE DE LA NATURE DES SUBSTITUANTS DANS LES REACTIONS D'EXTRUSION DE SOUFRE LORS DE L'ELABORATION DE LA CHARPENTE PYRIDO[2,3-<i>b</i>[1,4]THIAZEPINE
A strategy involving the reaction between an azaallylic anion linked to a chloropyridine and different O-ethyl thiocarboxylates has shown to be effective for the synthesis of 2-aryl and 2-heteroarylpyrido[2,3-b][1,4]thiazepine However the presence of a saturated cycle fused with the thiazepine ring results in distorsion of the parent molecule, thus weakening the conjugation, and consequently induces the sulfur extrusion from the preliminary formed cycloadduct giving rise finally to 1,5-naphthyridines.
Simple Preparation of Polyhydro-6-aryl(heteroaryl)cycloalka[<i>b</i>][1,5]naphthyridines
A variety of polyhydro-6-aryl- and heteroarylcycloalka[b][1,5] naphthyridines have been efficiently prepared by thermally induced ring contraction of pyrido[2,3-b][1,5]thiazepines obtained by reacting lithiated 2-chloro-N-cycloalkylidene-3-pyridinimines with suitable O-ethyl thiocarboxylates.
Rapid and Efficient Microwave-Assisted Synthesis of 4-, 5-, 6- and 7-Azaindoles
作者:Nicolas Lachance、Myriam April、Marc-André Joly
DOI:10.1055/s-2005-872100
日期:——
imines/ enamines formed between aminopyridines and ketones are converted in moderate to good yields to the corresponding 4-, 5-, 6- or 7-azaindoles via the Hegedus-Mori-Heck reaction (intramolecular Heck reaction). A systematic examination of all isomeric azaindoles synthesis revealed this one-pot procedure to be general in scope.