CpCo(I) precatalysts for [2 + 2 + 2] cycloaddition reactions: synthesis and reactivity
Sprache des Titels:
Englisch
Original Kurzfassung:
The efficient synthesis and structural characterisation of a series of novel CpCo(I)?olefin?phosphite/
phosphoramidite complexes and their evaluation in catalytic cyclotrimerisation reactions are reported. The
protocol for precatalyst synthesis is widely applicable to different P-containing ligands, especially
phosphites and phosphoramidites, as well as acyclic and cyclic olefins. A selection of the prepared
complexes was investigated towards their catalytic performance in [2 + 2 + 2] cycloaddition reactions of
diynes and nitriles, as well as triynes. While revealing significant differences in reactivity, the most reactive
precatalysts work even already at 75 °C. One of these precatalysts also proved its potential in exemplary
(co)cyclotrimerisations towards functionalised pyridines and benzenes. The energetics of complex
formation and exemplary ligand exchange with a substrate diyne were elucidated by theoretical
calculations and compared with the catalytic reactivity.