Selective metal promoted hydrolysis of nitrile groups in the side chain of tetraazamacrocyclic Cu2+-complexes.
The metal promoted hydrolysis of nitrile groups in the side chains of tetraazamacrocyclic Cu2+ complexes has been studied by stopped-flow techniques. It is shown that the reaction proceeds by an intramolecular attack of an axially coordinated OH- onto the nitrile group to give the corresponding amide. In alkaline solution the amide then deprotonates and binds to the axial position of the Cu2+ thus preventing further coordination of an OH-. This explains mechanistically that in the Cu2+ complexes of macrocycles carrying two nitrile functions only one is selectively hydrolysed. The nitrile hydrolysis has also been used on a preparative scale to synthesize tetraazamacrocycles with two different side chains. X-Ray diffractions of several products are presented to confirm the structures and the results from the kinetics and equilibria measurements.
Siegfried
Liselotte
L
Department of Chemistry, Spitalstr. 51, CH-4056 Basel, Switzerland.
Comparone
Antonio
A
Neuburger
Markus
M
Kaden
Thomas A
TA
D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006878:Hydroxides; D007700:Kinetics; D008968:Molecular Conformation; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
D001372:Aza Compounds; D006571:Heterocyclic Compounds; D006878:Hydroxides; D009570:Nitriles; D003300:Copper; C031356:hydroxide ion