10.1021/ja306947m.s004 Javier Carreras Javier Carreras Mahendra Patil Mahendra Patil Walter Thiel Walter Thiel Manuel Alcarazo Manuel Alcarazo Exploiting the π‑Acceptor Properties of Carbene-Stabilized Phosphorus Centered Trications [L<sub>3</sub>P] <sup>3+</sup>: Applications in Pt(II) Catalysis American Chemical Society 2012 nucleophilic attack ligand 3P phosphine 1 K 2PtCl acceptor Kinetic studies polycyclic homo DFT substitution patterns model transformation 2012-10-10 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Exploiting_the_Acceptor_Properties_of_Carbene_Stabilized_Phosphorus_Centered_Trications_L_sub_3_sub_P_sup_3_sup_Applications_in_Pt_II_Catalysis/2479078 Reaction of tris­(dimethylaminocyclopropenium) substituted phosphine <b>1</b> with K<sub>2</sub>PtCl<sub>4</sub> afforded the bench stable complex <b>3</b> which upon treatment with Ag­[CB<sub>11</sub>H<sub>6</sub>Cl<sub>6</sub>] turned out to be an excellent catalyst for the transformation of a variety of <i>ortho</i>-biaryl substituted alkynes into polycyclic homo- and heteroarenes of different size, shape, and curvature through a 6-<i>endo</i>-dig cyclization. This constitutes the first example ever reported of using a P<sub>1</sub>-centered trication as ligand in catalysis. The strong π-acceptor character of <b>1</b> that derives from its three positive charges substantially increases the intrinsic π-acidity of Pt in complex <b>1</b>·PtCl<sub>2</sub> and dramatically enhances its ability to activate π-systems toward nucleophilic attack. As a consequence, a remarkable acceleration of the model transformation is observed when compared with other classical π-acceptor ligands such as P­(OPh)<sub>3</sub> or P­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>. Moreover, the employment of <b>1</b> as ligand also expands the scope of this reaction to previously inaccessible substitution patterns. Kinetic studies and deuterium labeling experiments as well as density functional theory (DFT) calculations were performed in order to explain these findings.