Influence of Impurities on the Productivity in Homogeneous Catalytic Reactions: Trimerization of 1,4‐Dimethoxy‐but‐2‐yne and Tetramerization of Propargyl Alcohol

Abstract

AbstractThe productivity of homogeneous catalytic reactions is often described by the yield. This is misleading, and also the TON (turnover number) as well as the TOF (turnover frequency) which better describe it, give no objective informations. These data strongly depend on the substrate to catalyst ratio and also on impurities in the substrate which poison the effective catalyst and reduce the described yield as well as the turnover numbers and the turnover frequencies. In this concept a model is presented, how by changing the amounts of catalyst and the substrate it is possible with several restrictions to calculate the possible maximum for the TON. For the example of trimerization of 1,4‐dimethoxy‐but‐2‐yne to hexakis‐methoxymethyl‐benzene and for tetramerization of propargyl alcohol to 1,3,5,7‐ and 1,3,6,8‐hydroxymethyl‐1,3,5,7‐cyclooctatetraene by previous purification of the substrate or by certain additives as scavengers the access to these compounds is described in detail. By using both methods, extremely high turnover numbers a million were realized.