Facile activation of the C–I bond of primary alkyl halides by Pt(II) complexes having a benzothiazole ligand

Ligand-Mediated C–Br Oxidative Addition to Cycloplatinated(II) Complexes and Benzyl-Me C–C Bond Reductive Elimination from a Cycloplatinated(IV) Complex

“…Because our interests lie in the reactivity of cycloplatinated complexes, here, we show that although the cycloplatinated­(II) complex [PtMe­(C^N)­(PPh 2 Me)] (C^N = deprotonated 2-phenylpyridinine (ppy), 1b , or deprotonated benzo­[h]­quinoline (bhq), 1c ) reacts with benzyl bromide, PhCH 2 Br, to give exclusively the trans addition product, the previously reported complex [PtMe 2 (pbt)], 1a , (pbt = 2-(2-pyridyl)­benzothiazole) reacts uniquely with PhCH 2 Br to give a mixture isomeric products. The reactivity of Pt­(II) centers in these complexes as a nucleophile toward PhCH 2 Br is compared.…”

“…54 Also, we have recently reported on homocoupling of benzene. 6 Because our interests lie in the reactivity of cycloplatinated complexes, here, we show that although the cycloplatinated(II) complex [PtMe(C^N)(PPh 2 Me)] (C^N = deprotonated 2phenylpyridinine (ppy), 1b, or deprotonated benzo[h]quinoline (bhq), 1c) reacts with benzyl bromide, PhCH 2 Br, to give exclusively the trans addition product, the previously reported complex [PtMe 2 (pbt)], 55 ; C^N = bhq) in good yields through oxidative addition of PhCH 2 Br. Both complexes were characterized using multinuclear 1 H, 31 P, and 13 C NMR spectroscopy (see Table 1) and elemental analysis.…”

“…In the 13 C NMR spectrum (see Table 1 and Figure 3), for 2a, two singlets with Pt satellites are observed for the two different methyl groups directly connected to Pt, trans to N of pyridyl and benzothiazole rings. 55 The 1 J(PtC) values (see Table 1) are smaller than the corresponding values reported for the methyl groups of complex 1a ( 1 J(PtC) = 807 Hz and 844 Hz), 55 confirming the oxidation of Pt(II) to Pt(IV) by benzyl bromide. The CH 2 of benzyl appears at δ = 22.8 and was confirmed by DEPT 13 C analysis.…”

“…Kinetic studies were carried out using a Perkin-Elmer Lambda 25 spectrophotometer with temperature control using an EYELA NCB-3100 constant-temperature bath. Benzyl bromide and 2-(2-pyridyl)­benzothiazole (abbreviated as pbt) were purchased from commercial sources, and the precursor complexes [Pt 2 Me 4 (μ-SMe 2 )], [PtMe 2 (pbt)], 1a , [PtMe­(ppy)­(PPh 2 Me)], 1b , [PtMe­(bhq)­(PPh 2 Me)], 1c , and [PtIMe 2 (ppy)­(PPh 2 Me)], 4b , were prepared as reported.…”