We also tested the performance [5](BF4)3 in several enyne cyclization reactions carried out under the same conditions (Scheme 5b), all of which reached a full conversion within an hour. Cycloisomerization of a dimethyl-malonate substrate 14 proceeded smoothly, yielding exclusively the 5-exo product 15 (Table , entry 4). On the other hand, the tosylamide-based substrates featuring gem-disubstituted and trisubstituted alkenes, 16 and 18, respectively, formed mixtures of the corresponding 5-or 6membered cyclic dienes, 17a or 19a, with the cyclopropaneannulated products, 17b or 19b (Table , entries 5 and 6). All in all, ligand L3 demonstrated high activity in Pt(II)-catalyzed cycloisomerizations, being on par with the α-cationic phosphines and arsines studied by Alcarazo, but perhaps leaving room for improvement compared to certain Z-type antimony(V)-based ligands reported by Gabbai. In summary, the thiatriptycenium-based pincer ligand reported herein represents the first example of a cationic pincer ligand featuring a bicyclic backbone. We believe that the rigidity and stability of this novel ligand framework provides a promising platform for further structural fine-tuning, resulting in even greater catalytic activity in these and related chemical transformations. Exploration of such modifications are currently underway in our lab.