Novel Extensions of the <i>tert</i>-Amino Effect: Formation of Phenanthridines
and Diarene-Fused Azocines from <i>ortho</i>-<i>ortho</i>′-Functionalized Biaryls
azocines fused to two benzene rings or one benzene and one pyridazinone ring, which are otherwise difficult to access, were prepared via two new extensions of the tert- ' amino effect. The synthetic pathway includes three steps:i) Suzuki ] reaction of an ortho-functionalized phenylboronic acid with ortho- ] disubstituted benzenes or pyridazinones; ii) the Knoevenagel condensation reaction of the biaryl
ridazin-3(2H)-ones with 2-formylphenylboronic acid afforded the corresponding biaryl products which were cyclized with ammonia to yield hitherto undescribed pyridazino[4,5-c]isoquinolinones. Removal of the N-benzyl protective group in position 2 yielded the unsubstituted tricyclic pyridazinones.
2-烷基(甲基和苄基)-5-氯-4-甲氧基-和2-烷基(甲基和苄基)-4-氯-5-甲氧基吡啶并-3(2 H)-的Suzuki交叉偶联反应-甲酰基苯基硼酸得到相应的联芳基产物,将其用氨环化以产生迄今未描述的哒嗪并[4,5- c ]异喹啉酮。除去2位上的N-苄基保护基团得到未取代的三环吡啶并酮。