Chiral Bisphosphine BINAP-Stabilized Gold and Palladium Nanoparticles with Small Size and Their Palladium Nanoparticle-Catalyzed Asymmetric Reaction

Abstract

The reduction of tetrachloroaurate or potassium tetrachloropalladate with sodium borohydride in the presence of optically active 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl [BINAP] gave the chiral (S)- or (R)-BINAP-stabilized gold or palladium nanoparticles which showed the small core (1.7 nm for BINAP-Au and 2.0 nm for BINAP-Pd) with narrow size distribution and remarkably high stability. Asymmetric hydrosilylation of styrene with trichlorosilane in the presence of chiral BINAP-Pd nanoparticles afforded an optically active 1-phenyl-1-trichlorosilylethane which was converted into an optically active 1-phenylethanol (95% enantiomeric excess) by oxidative cleavage of the carbon-silicon bond.

Chirally modified gold nanoparticles: nanostructured chiral ligands for catalysis

“…17 To our knowledge, there have been very few reports on chiral gold nanoparticles up to date. 18 We now report a new chiral nanoligand with a gold core smaller than ever before in experimental chemistry. Since the dimensions of the gold core of our novel particle match those calculated by Johansson et al, 19 it is suggestive that we have formed a 32-atom gold cluster, resembling a fullerene structure.…”

P-Stereogenic Phosphines for the Stabilisation of Metal Nanoparticles. A Surface State Study

“…The enantioselective catalysis on surfaces is commonly explained by three main mechanisms: the presence of chiral crystalline atomic structures at the surface, chiral adsorbates which modify the surface and chiral modifiers which control the approach of the substrate on the surface [11,12]. The stereoselective reactions mainly concern hydrogenations and C-C bond formation reactions based on the third mechanism [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. In this context, the optically pure ligand should be able to generate both a strong enough coordination at the metallic surface to stabilize MNPs and an asymmetric environment to efficiently lead to one of the expected stereoisomers during the organic transformation.…”

“…Ligands coordinate at the metallic surface by different ways, such as dative donor bonds between heteroatoms of the ligands and the metal surface, and also by π-interactions through aromatic fragments of the ligands and the nanoparticle. The nature of the chiral stabilisers reported in the synthesis of MNPs is wide-ranging, including dienes [15], cinchona alkaloids [16][17][18], mono or bidentate amines [19][20][21], phosphorus-based ligands (phosphites [22][23][24][25][26], diphosphines [27][28][29][30], secondary phosphine oxide [31]). P-stereogenic phosphines are well-known in catalysis using organometallic complexes as catalytic precursors, finding applications in hydrogenation, transfer hydrogenation, cyclopropanation, hydrovinylation, Diels Alder reactions and allylic substitutions [32][33][34].…”

Optically active chiral Ag nanowires

“…This is the effect of the difference in speed and absorption of the leftand right-handed circularly polarized light when passing through the chiral materials. Such chiral plasmonic nanostructures provide potential applications in asymmetric catalysts [10,11], optical devices [12] and biological sensors [13−16].…”