Abstract
The reaction of 1,2-diaminoethane with vinylphosphonate occurs as the addition of the amino group to the β -carbon atom of the unsaturated substrate to give 1:1 and 1:2 adducts. The nucleophilic addition of 2-aminoethanol at the β -position of the double bond of vinylphosphonates involves only the amino group and leads to the formation of hydroxy β -aminoethylphosphonates or zwitterions depending on conditions.
Dedicated to Professor Marian Mikołajczyk, CBMiM PAN in Łódź, Poland, on the occasion of his 70th birthday.