to-medium conversion using monomer 1, with a catalyst loading of either 300 or 600 ppm (Scheme 2b). The reactions were monitored until the conversion of terminal double bonds ceased to increase. While G2 showed a TON of 1030 at 300 ppm loading, the use of the "classic" cyclometalated Ru-2 catalyst only resulted in a 5.4% conversion and a TON of 180. The bulkier pivalate catalyst Ru-3 and nitrate catalyst Ru-4 exhibit higher effectiveness, achieving TONs of 830 and 1770 at the same catalyst loading, respectively. Ru-2, Ru-3, and Ru-4 were further examined with a catalyst loading of 600 ppm to minimize the potential influence of impurities in monomer 1, and the measured TONs varied similarly to those with 300 ppm of catalysts. The use of 1000 ppm of Ru-4 was sufficient in generating P1 with a molar mass of 8.9 kg mol -1 . However, to facilitate the access to higher molar masses and an impartial assessment of the catalyst-dependent relationship between molar mass and cis-percentage, a unified catalyst loading of 0.3 mol% was utilized to investigate the ADMET of 1 with various catalysts (Scheme 2c). As a benchmark, the use of Ru-1 furnished P1 with a cis-percentage of 16% and a molar mass of 18.1 kg mol -1 (entry 1). When Ru-2 was used, a remarkable cis-percentage of 99% was observed after 18 hours. However, only 93% of the terminal alkenyl group had reacted, resulting in a relatively low molar mass of P1 (8.4 kg mol -1 ). While extending the reaction time did result in higher molar masses, a significant and continuous decrease in cispercentage was observed over time. For example, only a 97% cis ratio was achieved when the molar mass of P1 reached 10.4 kg mol - 1 , which further decreased to 94% when the molar mass increased to 12.7 kg mol -1 (entries 2-4). With a bulkier NHC side arm and a faster initiation rate, Ru-3 bearing a pivalate anion catalyzed a more efficient cis-selective ADMET than Ru-2, producing P1 with a molar mass of 13.1 kg mol -1 after 18 hours and 19.5 kg mol -1 after 48 hours. However, a significant drop in cis-percentage (from 99% to 95%) was still observed during the time frame of 18 to 30 hours (entries 5-7). Finally, the use of Ru-4, a bulkier catalyst with a nitrate anion, led to optimal cis-selective ADMET polymerization of 1 that exhibited fast polymerization kinetic, satisfactory molar masses, and slow erosion of stereoselectivity. After 18 hours of reaction with Ru-4, P1 was generated with a molar mass of 13.5 kg mol -1 and a cis-percentage of 99%. The molar mass continued to increase to 16.1 kg mol -1 over the following 12 hours, and the cispercentage only slightly decreased to 98% (entries 8 and 9). It is noteworthy that the ADMET reaction based on a stereoretentive mechanism using the corresponding ethyl-capped cis-diene could only afford P1 with 94% cis selectivity and a molar mass of 15.9 kg mol -1 , which highlights the effectiveness of the current approach based on terminal dienes. The effect of a higher Ru-4 loading (1 mol%) was investigated, resulting in a similar molar mass (16.6 kg mol -1 ) but reduced stereoselectivity (92% cis) after a prolonged reaction time (entry 10).