Construction of Pyridazine Analogues via Rhodium‐mediated C‐H Activation

Herein a rhodium (III)‐mediated catalysis was demonstrated for approaching the structurally divergent N,N‐bicyclic pyridazine analogues. The pyrazolidinone moiety was used to direct the ortho C−H activation and this led to a general synthesis of benzopyridazine analogues with satisfactory yields. The crucial effect of the base was illustrated in the sequential dehydration process. For mechanistic insight, control experiments were performed for illustration of the catalytic circle. Gram scale synthesis and several practical transformations were conducted for further applications. magnified image