1355535-70-4Relevant academic research and scientific papers
The aerobic oxidation of a Pd(II) dimethyl complex leads to selective ethane elimination from a Pd(III) intermediate
Khusnutdinova, Julia R.,Rath, Nigam P.,Mirica, Liviu M.
, p. 2414 - 2422 (2012)
Oxidation of the PdII complex (N4)PdIIMe2 (N4 = N,N'-di-tert-butyl-2,11-diaza[3.3](2,6)pyridinophane) with O2 or ROOH (R = H, tert-butyl, cumyl) produces the PdIII species [(N4)PdIIIMe2]+, followed by selective formation of ethane and the monomethyl complex (N4)PdIIMe(OH). Cyclic voltammetry studies and use of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap suggest an inner-sphere mechanism for (N4)PdIIMe 2 oxidation by O2 to generate a PdIII- superoxide intermediate. In addition, reaction of (N4)PdIIMe 2 with cumene hydroperoxide involves a heterolytic O-O bond cleavage, implying a two-electron oxidation of the PdII precursor and formation of a transient PdIV intermediate. Mechanistic studies of the C-C bond formation steps and crossover experiments are consistent with a nonradical mechanism that involves methyl group transfer and transient formation of a PdIV species. Moreover, the (N4)PdIIMe(OH) complex formed upon ethane elimination reacts with weakly acidic C-H bonds of acetone and terminal alkynes, leading to formation of a new PdII-C bond. Overall, this study represents the first example of C-C bond formation upon aerobic oxidation of a PdII dimethyl complex, with implications in the development of Pd catalysts for aerobic oxidative coupling of C-H bonds.
