Carbon‐iodide bond activation by cyclometalated Pt (II) complexes bearing tricyclohexylphosphine ligand: A comparative kinetic study and theoretical elucidation

Abstract

Yield: 76%. Elem. anal. Calcd for C 30 H 44 NPPt (644.73); C, 55.89; H, 6.88; N, 2.17. Found: C, 55.76; H, 6.82; N, 2.26. 1 H NMR (400 MHz, CDCl 3 ): δ = 1.07 (d, 3 J PH = 5.3 Hz, 2 J PtH = 84.5 Hz, 3H, PtMe), 1.20-1.40 (m, 9H, Cy), 1.65 (m, 6H, Cy), 1.70-1.90 (m, 9H, Cy), 1.97-2.14 (m, 6H, Cy), 2.36 (m, 3H, Cy), 7.09 (m, 1H, H 4′ ), 7.16 (t, 1H, 3 J HH = 7.3 Hz, H 5′ ), 7.35 (td, 1H, 3 J HH = 7.3 Hz, 4 J HH = 2.9 Hz, 4 J PtH = 29.7 Hz, H 5 ), 7.70 (bd, 1H, 3 J HH = 7.8, H 4 ), 7.85 (m, 2H, H 3 and H 6′ ), 7.95 (dd, 1H, 3 J HH = 6.3 Hz, 4 J HH = 1.1 Hz, 3 J PtH = 46.8 Hz, H 3′ ), 8.84 (d, 1H, 3 J HH = 5.6 Hz, 3 J PtH = 18.3 Hz, H 6 ); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ): δ = −15.3 (d, 2 Yield: 81%. Elem. anal. Calcd for C 32 H 44 NPPt (668.75); C, 57.47; H, 6.63; N, 2.09. Found: C, 57.31; H, 6.69; N, 2.21. 1 H NMR (400 MHz, CDCl 3 ): δ = 0.83-2.61 (3H of Me and 33H of Cy), 7.46 (dd, 1H, 3 J HH = 7.9 Hz, 3 J HH = 7.8 Hz, H 8 ), 7.56 (d, 1H, 3 J HH = 8.1 Hz, H 6 ), 7.67 (d, 1H, 3 J HH = 8.1 Hz, H 5 ), 7.74 (m, 1H, H 3 ), 7.82 (d, 1H, 3 J HH = 8.7 Hz, H 7 ), 8.23 (dd, 1H, 3 J HH = 7.1 Hz, 3 J PtH = 45.5 Hz, H 9 ), 8.34 (d, 1H, 3 J HH = 8.3 Hz, H 4 ), 9.15 (d, 1H, 3 J HH = 5.3 Hz, 4 J HH = 1.1 Hz, 3 J PtH = 17.2 Hz, H 2 ); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ): δ = −16.0 (d, 2 J PC = 7 Hz, 1 J PtC = 754 Hz, PtMe), 26.6 (s, C of PCy 3 ), 1 H NMR (400 MHz) in CDCl 3 : δ = 0.86-2.11 (39H, aliphatic region, overlapping multiplets of 2Me and 3Cy), 7.21 (m, 1H, 3 J HH = 6.6 Hz, H 4′ ), 7.50 (dd, 2H, 3 J HH = 6.5 Hz, 4 J HH = 2.1 Hz, 4 J PtH = 53.1 Hz, H 5 and H 3′ ), 8.03 (m, 1H, 3 J HH = 7.9 Hz, 3 J HH = 7.8 Hz, H 4 ), 8.22 (d, 1H, 3 J HH = 6.5 Hz, H 5′ ), 10.09 (d, 3 J HH = 5.5 Hz, 4 J PtH = 16.1 Hz, 1H, H 3 ), 10.26 (d, 1H, 3 J HH = 7.83 Hz, 1H, H 6 ); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ): δ = −7.3 (d, 2 J PC = 4 Hz, 1 J PtC = 624 Hz, PtMe (Me trans to N)), 10.7 (d, 2 J PC = 106 Hz, 1 J PtC = 461 Hz, PtMe (Me trans J PtP = 955 Hz, 1P of PCy 3 ); 195 Pt{ 1 H} NMR (86 MHz, CDCl 3 ): δ = −3215.1 (s, 1 J PtP = 957 Hz, 1Pt). 4.3.2 | cis-[PtMe 2 I(k 2 N,C-ppy)(PCy 3 )] (2a) 1 H NMR (400 MHz) in CDCl 3 : δ = 0.85-2.12 (39H, aliphatic region, overlapping multiplets of 2Me and 3Cy), 7.22 (dd, 3 J HH = 7.8 Hz, 3 J HH = 7.3 Hz, 1H, H 4′ ), 7.33 (m, 2H, H 5′ and H 6′ ), 7.50 (d, 2H, 3 J HH = 7.8 Hz, 4 J PtH = 48.9 Hz, H 3′ ), 7.71 (m, 1H, H 4 ), 7.87 (ddd, 3 J HH = 7.5 Hz, 3 J HH = 8.0 Hz, 4 J HH = 1.3 Hz, 1H, H 5 ), 7.96 (d, 1H, 3 J HH = 8.1 Hz, H 3 ), 10.12 (d, 1H, 3 J HH = 14.8 Hz, H 6 ); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ): δ = −7.3 (d, 2 J PC = 3 Hz, 1 J PtC = 670 Hz, PtMe (Me trans to N)), 10.4 (d, 2 J PC = 109 Hz, 1 J PtC = 469 Hz, PtMe (Me trans to P)), 26.4 (s, C of PCy 3 ), 27.9 (d, 3 J PC = 10 Hz, C of

Oxidative Addition of a Hypervalent Iodine Compound to Cycloplatinated(II) Complexes for the C–O Bond Construction: Effect of Cyclometalated Ligands

“…According to the literature, a substantial number of studies have asserted that in the S N 2-type OA mechanism, , the metal center can act as a nucleophile in which increasing positive charge density leads to the retardation of the rate of reaction. , Hence, several research groups − have addressed this problem with the aid of computational studies based on the experimental data to not only calculate the Pt charge but also to determine and justify the mechanism of OA reaction. On the basis of this strategy, we have employed density functional theory (DFT) calculations for the reaction of 1a and diacetate reagent (PhI­(OAc) 2 ).…”

DFT Study on the Gold(I)‐Catalyzed Dehydrogenative Heterocyclization of 2‐(1‐Alkynyl)‐2‐alken‐1‐ones to form 2,3‐Furan‐Fused Carbocycles: Effects of Additives C5H5NO vs. PhNO

“…The double‐ζ basis set (6‐31G*) is employed for N, C, O, Cl, P and H elements, while Au element is described using the effective core potential double‐ζ basis set (LanL2DZ) . This combination of basis sets (6‐31G* and LanL2DZ) has also been proven to be reliable in numerous theoretical simulations of mechanisms of metal‐catalyzed reactions . As a further test, other basis sets 6‐31G**, 6–31 + G* and 6‐311G* (triple‐zeta) are employed for comparison to avoid the shortcomings of basis sets (see Table S2 in Supporting Information).…”

“…[47] This combination of basis sets (6-31G* and LanL2DZ) has also been proven to be reliable in numerous theoretical simulations of mechanisms of metal-catalyzed reactions. [37,[40][41][42][48][49][50] As a further test, other basis sets 6-31G**, 6-31 + G* and 6-311G* (triple-zeta) are employed for comparison to avoid the shortcomings of basis sets (see Table S2 in Supporting Information). All stationary points are verified by frequency calculations at the same level of theory to obtain zero-point energy (no imaginary frequency for an equilibrium structure and one imaginary frequency for a transition state structure).…”

Rollover Cyclometalation as a Valuable Tool for Regioselective C–H Bond Activation and Functionalization

“…In a successive paper, the same group studied the influence of the rollover cyclometalated ligand, comparing the cyclometalated N-O bipyridyl ligand with the classical deprotonated phenylpyridine and benzo[h]quinoline ligands [ 117 ]. The study showed that the reaction rate in the oxidative addition of MeI is significantly slower with the bipy- N -oxide ligands, showing the effect of the N-O group on the Pt(II) reactivity.…”