A new series of 20- and 25- membered polyacetylenic azamacrocy- cles have been satisfactorily prepared and completely characterised by spec- troscopic methods. Various [2+2+2] cy- clotrimerisation processes catalysed by the Wilkinson's catalyst, [RhCl- (PPh3)3], were tested in the above- mentioned macrocycles. The 25-membered azamacrocycle (like the previously synthesised 15-membered azama- crocyle) led to the expected cyclotri-merised compound in contrast to the 20-membered macrocycle, which is characterised by its lack of reactivity. The difference in reactivity of the 15-, 20- and 25-membered macrocycles has been rationalised through density functional theory calculations.
|Journal||Chemistry - A European Journal|
|Publication status||Published - 18 May 2009|
- Density functional calculations
- Reaction mechanisms