Rapid Synthesis of Aromatic Polyamide Dendrimers by an Orthogonal and a Double-Stage Convergent Approach

Aromatic polyamide dendrons (HOOC-G1 (6), Br-G2 (7), HOOC-G3 (8), and Br-G4 (9)) were synthesized by an orthogonal approach, which utilizes the direct condensation reaction and palladium-catalyzed carbon monoxide insertion reaction in an alternating fashion to form amide linkages. G1, possessing four amino groups (HOOC-G1-4NH2 (12)), and G2, possessing eight amino groups (HOOC-G2-8NH2 (14)), were also prepared independently. HOOC-G4 (15) was synthesized from 12 and 7, and HOOC-G5 (16) from 14 and 7 both with the double-stage convergent method. The aramid dendrons were soluble in amide solvents and THF. The coupling of dendrons with difunctional and trifunctional core molecules was attempted.