Polypropylenimine dendrimers: Improved synthesis and characterization

Both the Michael addition and the hydrogenation steps in the large scale synthesis of polypropylenimine dendrimers have been improved: by adding ammonia during the hydrogenations the substrate concentrations can be increased 8 times, the catalyst concentration can be lowered 10 times and the average selectivity remains > 99.5% per conversion. The dimensions of the dendrimers have been studied with SANS and with molecular calculations.