Ferrocenylphosphine-gold complexes

Ferrocenylphosphine-gold complexes, 225 Formaldehyde oligomerization, 332 Formic acid, transfer hydrogenation, 123 Formulas, chiral compounds, xiii-xvii Four-dimensional chemistty. See Asymmetric catalysis... 

Table 11 Enantioselectivity and Diastereoselectivity in the Aldol Reactions of Methyl Isocyanoacetate Under Catalysis by Chiral Ferrocenylphosphine-Gold Complexes (equation 22)...

Catalysis by Chiral Ferrocenylphosphine-Gold Complexes (equation 22)... 

Hayashi-Ito asymmetric Aldol reaction with chiral ferrocenylphosphine-gold complex. 

Asymmetric Aldol Reactions with a Chiral Ferrocenylphosphine-Gold( I) Complex... 

In 1986 Ito, Sawamura, and Hayashi [4] reported that gold(I) complexes prepared from cationic gold complex 1 and chiral ferrocenylphosphine ligands (2) bearing a tertiary amino group at the terminal position of a pendant chain are effective catalysts for asymmetric aldol reaction of... 

Soloshonok and Hayashi applied chiral ferrocenylphosphine-gold(I) complexes to asymmetric aldol-type reactions of fluorinated benzaldehydes with methyl isocyano-acetate (27) and A, A/-dimethyl-a-isocyanoacetamide (95). It is noteworthy that successive substitution of hydrogen atoms by fluorine in the phenyl ring of benzaldehyde causes gradual increase of both the cis selectivity and the ee of cw-oxazolines [53]. 

The ferrocenylphosphine-silver complex catalyzes the aldol-type reaction of tosylmethyl isocyanide 71 with aldehydes with higher stereoselectivity than the gold complex (Scheme 2-59) [84]. The reaction with several aldehydes produces trans-4-tosyloxazolines 72 in up to 86% ee, which can be converted into optically active l-alkyl-2-aminoethanols by reduction with LiAlH4. 

N-methyl-6-hydroxy-amino acids, such as the amino acid MeBmt (32). The aldol condensation of aldehydes with isocyanoacetate in the presence of a chiral ferrocenylphosphine-gold(I) complex afforded... 

It has been reported that a chiral ferrocenylphosphine-gold(I) complex catalyses the asymmetric aldol reaction of an isocyanoacetate... 

Other work involving complexation of ferrocenylphosphines include the preparation of silver complexes of diferrocenylphosphine a trinuclear dirhenium complex dppf as a spacer ligand between rhenium centres dppf in gold complexes palladium and platinum complexes from the carboxylation of [(dppf)MCl2], M = Pd, Pt complexes technetium and rhenium heterometallic complexes mixed silver/nickel complexes ... 

Catalytic asymmetric aldol reaction reaction of aldehydes with isocyanoacetate catalyzed by a chiral ferrocenylphosphine-gold(I) complex, Y. Ito, M. Sawamura, and T. Hayashi, J. Am. Chem. Soc., 1986,... 

The gold(I) complex of a chiral ferrocenylphosphine complex promotes asymmetric aldol reactions of a-isocyanocarboxylates to form chiral oxazolines in high diastereo- and enantio-selectivities (Scheme 52).225,226 In these reactions, the analogous silver(I) ferrocenylphosphine complex also works well. 

Asymmetric aldol reaction. In the presence of a gold(I) complex (1) and a chiral ferrocenylphosphine (2), various aldehydes react with methyl isocyanoacetate... 

Ferrocenyl ligands, via zinc reagents, 9, 120 Ferrocenylmethyl phosphonium salts, with gold(I), 2, 274 Ferrocenylmonophosphine, in styrene asymmetric hydrosilylation, 10, 817 Ferrocenyl oxazolines, synthesis, 6, 202 Ferrocenylphosphines with chromium carbonyls, 5, 219 in 1,3-diene asymmetric hydrosilylation, 10, 824-826 preparation, 6, 197 various complexes, 6, 201 Ferrocenylselenolates, preparation, 6, 188 Ferrocenyl-substituted anthracenes, preparation, 6, 189 Ferrocenyl terpyridyl compounds, phenyl-spaced, preparation 6, 188 Ferrocifens... 

Table 3. Diastereo- and enantioselective aldol reaction of methyl isocyanoacetate (27) with tildehydes catalyzed by chiral ferrocenylphosphine 86c gold(I) complex.

Ito and coworkers found that chiral ferrocenylphosphine-silver(I) complexes also catalyze the asymmetric aldol reaction of isocyanoacetate with aldehydes (Sch. 26) [51]. It is essential to keep the isocyanoacetate at a low concentration to obtain a product with high optical purity. They performed IR studies on the structures of gold(I) and silver(I) complexes with chiral ferrocenylphosphine 86a in the presence of methyl isocyanoacetate (27) and found significant differences between the iso-cyanoacetate-to-metal coordination numbers of these metal complexes (Sch. 27). The gold(I) complex has the tricoordinated structure 100, which results in high ee, whereas for the silver(I) complex there is an equilibrium between the tricoordinated structure 101 and the tetracoordinated structure 102, which results in low enantioselectivity. Slow addition of isocyanoacetate 27 to a solution of the silver(I) catalyst and aldehyde is effective in reducing the undesirable tetracoordinated species and results in high enantioselectivity. 

Tributylphosphine sulfide has been used as a co-catalyst with dicobalt octacarbonyl for the Pawson-Khand reaction. Thermolysis of a mixture of cadmium chloride and trioctylphosphine sulfide at 250 °C has been used as a route to the formation of nanocrystalline cadmium sulfide." A complex of triphenylphosphine sulfide with a silver-tungsten-iodine acceptor has been characterised by X-ray studies. Ferrocenylphosphine chalcogenides have attracted considerable interest as ligands. Complexes of the monophosphino-phosphine sulfide (269) with rhodium have been characterised." The disulfide (270) forms complexes with both gold(i) and gold(iii) acceptors," and a silver(i) complex of the diselenide (271) has been prepared. ... 

Gold(I) complexes prepared in situ from bis(cyclohexyl isocyanide)gold(I) tetrafluoroborate (1) [3] and chiral ferrocenylphosphine ligands (i )-(S)-2a-e [4,... 

Gold(I)/ferrocenylphosphine 2a-d complexes are applicable to asymmetric aldol reactions of a-alkyl substituted a-isocyanoacetates 12. Although the dependency of stereoselectivity on the structures of the substrates is fairly large, some combinations of 12 and aldehydes show high enantio- and diastereoselec-tivity (Scheme 3). The reaction with paraformaldehyde yields (S)-4-alkyl-2-ox-azoHne-4-carboxylates in 64 to 81% ee, which can be readily transformed to the... 

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