Kinetico-mechanistic studies on C X (X = H, F, Cl, Br, I) bond activation reactions on organoplatinum(II) complexes

A kinetic approach to carbon–iodide bond activation by rollover cycloplatinated(II) complexes containing monodentate phosphine ligands

“…The data are collected in Table 1. These observations suggest an S N 2 mechanism of oxidative addition of MeI to the rollover cycloplatinated(II) complexes [6,64]. It is interesting to note that the observed rate constants for the reaction of rollover 2,2 0 -bipyridine complexes, [PtMe(bpy-H) (L)], with MeI are lower than the related rate constants reported for [PtMe(ppy) (L)] (ppy ¼ 2-phenylpyridinate) complexes [41] (see Table 1).…”

Secondary kinetic deuterium isotope effect in oxidative addition reaction of cycloplatinated(II) complexes with MeI

“…The cyclometalated platinum(II) complexes with a rather electron rich Pt(II) centers were the substrates of choice because they are potentially capable of reacting by different mechanisms such as S N 2 (producing the kinetically trans addition product) or concerted three-center one (directly producing the cis addition product) [9,10]. Thus, we studied secondary a-deuterium KIEs in oxidative addition reaction of the cycloplatinated(II) complexes [PtMe(C^N) (L)], in which C^N ¼ 2-phenylpyridinate (ppy) or benzo[h]quinolinate (bhq) and L ¼ PPh 3 , PMePh 2 or P(OPh) 3 , with CH 3 I/CD 3 I.…”

Reaction of dimethylplatinum(II) complexes with PhCH2CH2Br: Comparative reactivity with CH3CH2Br and PhCH2Br and synthesis of Pt(IV) complexes

“…[2] SCHEME 2 S N 2 mechanism for oxidative addition of alkyl halides RCH 2 Br (R = CH 3 , Ph and PhCH 2 ) to complex 1a FIGURE 4 Activation energy profile for the oxidative addition reactions of complex 1a with RCH 2 Br (R = CH 3 , Ph and PhCH 2 ) (see Scheme 2) in acetone solvent For a discussion of the influence of alkyl halides on the rate of the oxidative addition reactions of complex 1a with RCH 2 Br (R = CH 3 , Ph and PhCH 2 ), their calculated activation energies are plotted in Figure 4. According to Figure 4, the calculated data indicate that the order of reactivity of RCH 2 Br with complex 1a is R = Ph > CH 3 > PhCH 2 .…”

“…[1][2][3] These oxidative addition reactions to square planar transition metal complexes play fundamental roles in many industrially important catalytic processes, producing high-value-added organic compounds. [4] The reactions generally proceed through an S N 2 mechanism, involving a second-order rate law such as v = k 2 [complex][halide], [5][6][7] although radical or concerted (via a three-centre transition state) mechanisms are also a possibility.…”

“…The crystal structure of 2a was further determined using X-ray crystallography indicating an octahedral geometry around the platinum centre. A comparison of reactivity of RCH 2 Br reagents (R = CH 3 , Ph or PhCH 2 ) in their oxidative addition reactions with complex 1a, with an emphasis on the effects of the R groups of alkyl halides, was also conducted using density functional theory. KEYWORDS alkyl halide, DFT calculation, mechanism, oxidative addition, platinum…”