Characterization of a Poly‐4‐Vinylpyridine‐Supported CuPd Bimetallic Catalyst for Sonogashira Coupling Reactions

Abstract

CuPd bimetallic solvated metal atoms (SMA) synthesized by metal vapor synthesis (MVS) technique and supported on poly-4-vinylpyridine (PVPy) resin, showed significantly higher catalytic activity in Sonogashira-type carbon-carbon coupling reactions than the corresponding monometallic Cu and Pd systems as well as their physical mixture. The analysis of the bimetallic catalyst combining transmission electron microscopy techniques and X-ray absorption fine structure (XAFS) spectroscopy revealed the presence of small Pd nanoparticles (d =2.5 nm) while the analysis of the X-ray absorption data, at the Cu K-edge suggests the formation of thin and incomplete Cu oxide layers around the Pd-rich cores.

Total Synthesis of Asparenydiol by Two Sonogashira Cross-Coupling Reactions Promoted by Supported Pd and Cu Catalysts

“…For the first Sonogashira cross-coupling, we tested a range of commercially available supported palladium catalysts [Pd EnCat™40, FibreCat 1007, Pd(PPh 3 ) 4 PS, and PdCl 2 (PPh 3 ) 2 /PS] and two polyvinylpyridine(PVPy)-supported catalysts recently developed by our research group (Cu/PVPy and Pd-Cu/PVPy). 26,27 The ability of the PVPy resin to promote M-H-type alkenylations, ensuring also very low metal leaching, was previously reported. 28,29 The reaction conditions were initially optimized using Pd EnCat TM 40 as a catalyst (Table 1), because this was already successfully tested for the synthesis of some natural compounds.…”

“…Pd-Cu/PVPy is not a simple mixture of segregated Pd and Cu nanoparticles dispersed on PVPy. 26 In this catalyst, an oxidized Cu(II) phase is…”

Green synthesis of graphene oxide (GO)-anchored Pd/Cu bimetallic nanoparticles usingOcimum sanctumas bio-reductant: an efficient heterogeneous catalyst for the Sonogashira cross-coupling reaction

“…There are several methods for the synthesis of metal nanoparticles using toxic and expensive chemicals. In the recent past, Sonogashira cross-coupling reaction with various heterogeneous bimetallic nanoparticles have been reported, such as Pd-Ni on ZIF-8, 22 Pd-Cu nanoparticles on magnesium oxide, 23 hollow Pd-Fe nanospheric catalyst, 24 Cu-Pd on poly-4-vinylpyridine, 25 gold-copper ferrite nanoparticles on silica microparticles, 26 Pd-Cu on graphene quantum dots modied Fe 3 O 4 nanoparticles, 27 hollow Pd-Co nanospheres, 6 Pd-Co nanoparticles on graphene, 28,29 Pd-Cu nanoparticles on macroporous ion-exchange resin, 7 Pd-Cu nano alloys on montmorillonite, 30 Pd-Co nanoparticles on polypropylenimine graed graphene, 31 Pd-Au on carbon, 32 CuPd nanoparticles on reduced graphene oxide, 2 etc. However, most of the above mentioned protocols suffered from serious disadvantages, viz.…”

Highly Crystallized Pd/Cu Nanoparticles on Activated Carbon: An Efficient Heterogeneous Catalyst for Sonogashira Cross-Coupling Reaction

“…The "Cu effect" represents an adjustment or modification of the catalytic ability in Pd-catalyzed Sonogashira coupling reactions [19][20][21]. Recently, several Pd/Cu bimetallic nanoparticles (NPs) were loaded on commercially available insoluble organic or inorganic supports as heterogeneous catalysts, and were successfully used in cross-coupling reactions and other chemical reactions [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. Supported bimetallic NP catalysts with minimal or no leaching are necessary for both environmental protection and cost reduction.…”