Reactivity and synthetic applications of bis(iminophosphoranes). One-pot preparation of pyrido[2,3,4-de]quinazolines and benzo[de][1,6]naphthyridines
摘要:
Aza-Wittig reaction of bis(iminophosphorane) 4 with 2 equiv of isocyanate leads directly to pyrido[2,3,4-de]quinazolines 5. Iminophosphoranes 8, available from 4 and 1 equiv of the appropriate isocyanate, react either with 1 equiv of isocyanate or ketene to give pyrido[2,3,4-de]quinazolines 9 or benzo[de][1,6]naphthyridines 10, respectively. Bis(iminophosphorane) 4 by sequential treatment with aldehydes and isocyanates yielded 2,3-dihydropyrido[2,3,4-de]quinazolines 17.
One pot preparation of pyrido[2,3,4-de]quinazolines and benzo[de][1,6]naphthyridines by a consecutive process involving an aza-Wittig/electrocyclic ring-closure/heterocumulene-mediated annelation or intramolecular Diels-Alder cycloaddition sequence.
作者:Pedro Molina、Mateo Alajarín、Angel Vidal
DOI:10.1016/s0040-4039(00)92391-8
日期:1991.9
Wittig-type reaction of bis(iminophosphorane)1 with one mole of isocyanate leads to the iminophosphoranes 5 which by treatment with a second mole of isocyanate afforded pyrido[2,3,4-de]quinazolines 6. Similarly, reaction with ketenes leads to the formation of benzo[de][1,6]naphthyridines 9. Directconversion 1→6 and 1→9 were achieved using two moles of isocyanate or ketene respectively.
Reactivity and synthetic applications of bis(iminophosphoranes). One-pot preparation of pyrido[2,3,4-de]quinazolines and benzo[de][1,6]naphthyridines
作者:Pedro Molina、Mateo Alajarin、Angel Vidal
DOI:10.1021/jo00051a007
日期:1992.12
Aza-Wittig reaction of bis(iminophosphorane) 4 with 2 equiv of isocyanate leads directly to pyrido[2,3,4-de]quinazolines 5. Iminophosphoranes 8, available from 4 and 1 equiv of the appropriate isocyanate, react either with 1 equiv of isocyanate or ketene to give pyrido[2,3,4-de]quinazolines 9 or benzo[de][1,6]naphthyridines 10, respectively. Bis(iminophosphorane) 4 by sequential treatment with aldehydes and isocyanates yielded 2,3-dihydropyrido[2,3,4-de]quinazolines 17.