Progress toward the polymerization of a fourth generation dendritic macromonomer

The g-scale synthesis of the fourth generation dendronized monomer 3d and i ts Suzuki oligomerization are reported. The monomer synthesis uses the fact that the addition of two G-3 fragments to aryldibromide 3c which already c ontains one branching unit is more practical than an alternative approach b y which a G-4 dendron is added to a respective compound. The Suzuki cross-c oupling of 3d gives oligomeric material 5, a fraction of which with a molec ular weight of (M) over bar(n) = 170000 is obtained by preparative gel perm eation chromatography. This finding shows that the Suzuki cross-coupling re action can cope with considerable steric loading of coupling components whi ch opens up new perspectives for its applicability both in organic and poly mer chemistry.