A new family of poly (phenylene-pyridyl) dendrimers (up to the fourth generation) with different periphery was synthesized via a divergent route by using a cascade of Diels-Alder cycloadditions. Tetra (4-ethynylphen-1-yl) methane served as a core. A new A2B cyclopentadienone building block, namely, pyridine-containing cyclopentadienone with protected dienophile functions was prepared. By varying the building blocks at the last ...