New catalysts based on Yb(salen) complexes active for the copolymerization of cyclohexene oxide (CHO) and CO2 to give poly(cyclohexene)carbonate (PCHC) are reported. In combination with co-catalytic, nucleophilic chloride additives these new (binary) catalysts provided good conversion and selectivity for PCHC formation with average turnover frequencies of up to 35 h-1 and narrow molecular weight distributions. The best results were obtained with the binary catalyst system 1 (0.1 mol%)/NBu4Cl (0.05 mol%), and at 90 °C a conversion of 57% was reached after 18 h with a TOF of 31 h1, and the polycarbonate had an Mn of 10.2 Kg/mol and a PDI of 1.54. Comparative catalysis studies have also been performed with a series of literature systems based on transition metal/lanthanide salen complexes, and the newly presented catalysts show comparatively good activity as well as copolymerization selectivity. MALDI-ToF mass spectrometric analysis revealed that trace water contamination and/or traces of 1,2-cyclohexane- diol were responsible for chain transfer effects limiting to some extent the maximum molecular weights that can be achieved in the current reactor set up.