Highly selective monomethylation of primary amines through host-guest product sequestration.
This Communication reports the highly selective monomethylation of primary amines through host-guest product sequestration. Complete control of the outcome of the N-methylation reaction has been achieved by adding to the reaction medium stoichiometric amounts of a teraphosphonate phosphonate cavitand Tiiii, capable of selectively and quantitatively trapping the monomethylated ammonium salt formed. The synergistic combination of ion-dipole, H-bonding, and CH(3)-pi interactions provide the high association constants (K(ass) > 10(9)) and the specific complexation mode necessary for the exclusive sequestration of the monomethylated intermediate reaction product.
Yebeutchou
Roger M
RM
Dipartimento di Chimica Organica e Industriale, Università di Parma, and INSTM UdR Parma, 43100 Parma, Italy.
Dalcanale
Enrico
E