Reactivity of the Nitrogen-Silicon Bond. Pyridines and Furo[2,3-b][1,4]diazepines from 4-Amino-1-azabutadienes via 1,2-Dihydro-1,3,2-diazasilines

José Barluenga; Miguel Tomás; Alfredo Ballesteros; Jian-She Kong

doi:10.1055/s-1992-34176

Synthesis 1992; 1992(1/2): 106-112
DOI: 10.1055/s-1992-34176

paper

© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Reactivity of the Nitrogen-Silicon Bond. Pyridines and Furo[2,3-b][1,4]diazepines from 4-Amino-1-azabutadienes via 1,2-Dihydro-1,3,2-diazasilines

José Barluenga^* , Miguel Tomás, Alfredo Ballesteros, Jian-She Kong

^*Departamento de Química Organometálica, Facultad de Química, Universidad de Oviedo, E-33071-Oviedo, Spain

Abstract

PDF Download All articles of this category

1,2-Dihydro-1,3,2-diazasilines 2 are prepared from 4-amino-1-azadienes 1 and react with dialkyl acetylenedicarboxylates to produce six- and seven-membered heterocycles depending on the substitution pattern of 1. Highly functionalized pyridine-2-carboxylates 5 and 8,8a-dihydro-2H-furo [2,3-b][1,4]diazepin-2-ones 11 are formed starting from azadienes 1 with R³ = H and R² = R³ = H, respectively. On heating diazepines 11 undergo ring-contraction to alkyl 4-hydroxy-5-(iminomethyl) pyridine-2-carboxylates 13 which can be hydrolyzed to the corresponding 5-formyl-4-hydroxypyridine-2-carboxylates 14.

PDF (580 kb)