作者:A.E. Frissen、G. Geurtsen、A.T.M. Marcelis、H.C. van der Plas
DOI:10.1016/s0040-4020(01)85440-5
日期:1990.1
undergo intramolecular inverse electron demand Diels-Alder reactions into the corresponding annelated pyridine derivatives under considerably milder conditions than the corresponding neutral pyrimidines. Protonation of the pyrimidine ring also facilitates the intramolecular Diels-Alder reaction. Protonation of less activated pyrimidines leads, however, to products resulting from an intramolecular coplanar
在2-或5-位带有双亲性侧链的N-烷基嘧啶阳离子在比相应的中性嘧啶温和得多的条件下经历分子内逆电子需求Diels-Alder反应成相应的退火的吡啶衍生物。嘧啶环的质子化也促进了分子内Diels-Alder反应。然而,较少活化的嘧啶的质子化导致由分子内共平面环胺化反应产生的产物。