Regioselective Asymmetric Allylic Alkylation Reaction of α‐Cyanoacet­ates Catalyzed by a Heterobimetallic Platina‐/Palladacycle

Abstract

Allylic substitution reactions provide a valuable tool for the functionalization of CH acidic pronucleophiles. Often, control over the stereocenter generated at the nucleophilic reactant is still a challenge. The majority of studies that address this issue employ metal complexes with a low metal oxidation state (e.g. Pd0) to form allyl complexes through oxidative addition. In this article we describe the use of heterobimetallic PtII/PdII complexes, which probably activate the olefinic substrates through an SN2′ pathway. The reaction of α‐cyanoacetates delivers linear allylation products with exclusive regioselectivity and high E/Z‐selectivity for the new C=C double bond. Although the enantioselectivities attained are moderate, they are significantly higher than with related mono‐PdII or ‐PtII catalysts or the corresponding bis‐PdII complex, which indicates cooperation of the different metals. Control experiments suggest simultaneous activation of both reaction partners.

Synthesis and hydrogenation application of Pt–Pd bimetallic nanocatalysts stabilized by macrocycle-modified dendrimer

“…In comparison to monometallic nanoparticles, bimetallic nanoparticles have unique properties, such as synergistic electric effect, high selectivity, efficient catalytic activity and cost-effectiveness [10][11][12][13]. Among these bimetallic nanoparticles, supported palladium-metal (Pd-M) bimetallic nanoparticle catalysts have attracted considerable attention because of their remarkable activity and high selectivity [14][15][16][17]. It is worth noting that the catalytic activity of Pd-M nanoparticle catalysts could be further enhanced by developing novel preparation strategies, selecting suitable support materials and introducing a second or even third ingredient to form bimetallic or multimetallic nanoparticles [15,18].…”