Stable catalyst for intermolecular Pauson–Khand reaction

Abstract

The catalytic activity of previously formed Co 2(CO) 6[P(Ph) 3] 2 ( 1) was compared with Co 2(CO) 8 and the system formed by Co 2(CO) 8 plus PPh 3 in the intermolecular Pauson–Khand (PK) reaction between norbornadiene and phenylacetylene. The effects of pressure, catalyst concentration and temperature were also studied. Additionally, the catalytic activity of complex 1 was compared with Co 2(CO) 6[P(OPh) 3] 2 ( 2) in the intermolecular PK reaction between strained alkenes and terminal and non-terminal alkynes. Both catalysts are very stable, quite efficient and interestingly complex 2 leads to double PK reaction. The results indicate that these complexes are attractive alternatives to Co 2(CO) 8 as catalyst and in addition, complex 2 is an alternative catalyst for double cyclocarbonylation reaction.