Ruthenium catalyzed reactions of ethylene glycol with primary amines: steric factors and selectivity control

Article abstract of DOI:10.1016/0022-328X(91)83143-R

The selectivity of reactions of ethylene glycol with primary amines in the presence of RuCl2(PPh3)3 at 120 deg C is highly dependent on the steric nature of the amine.Selectivity to di-amination is favored by smaller alkyl groups on the amine while large amines cleanly yield ethanolamines.This contrasts with the results obtained with secondary amines at this temperature, in which ruthenium-triphenylphosphine catalyst systems always favor mono-amination.In the case of sec-butyl amine, where almost equal amounts of mono- and di-aminated product are obtained, the selecti vity can be shifted to mono-amination by the addition of excess triphenylphosphine.The steric effects seen in these reactions are consistent with standard steric parameters availble from the literature.