Ester- and amide-terminated dendrimers with alternating amide and ether generations

Ester-terminated polyamide dendrimers up to the third generation and amide- terminated polyamide dendrimers of the first generation were synthesized by convergent growth. The Williamson ether synthesis and diphenylphosphoryl a zide (DPPA) coupling of amines to carboxylic acids were used for the constr uction of the dendrimers, having alternate ether and amide generations. The methyl ester- and N,N-diethylamide-terminated dendrimers were readily solu ble in common organic solvents while the N-methylamide- and N-benzylamide-t erminated dendrimers were soluble only in DMF and DMSO. Both the end and in ternal amide groups of the N,N-diethylamide-terminated dendrimer were reduc ed by LiAlH4 to form a polyamine dendrimer. (C) 2000 John Wiley & Sons, Inc .