scholarly journals Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

2011 ◽  
Vol 7 ◽  
pp. 555-564 ◽  
Author(s):  
Lian-jun Liu ◽  
Feijun Wang ◽  
Wenfeng Wang ◽  
Mei-xin Zhao ◽  
Min Shi
Keyword(s):  
Crystal Structure ◽  
Coupling Reactions ◽  
Gold Complexes ◽  
X Ray ◽  
Catalytic Activities ◽  
Axially Chiral

Axially chiral mono(NHC)–Pd(II) and mono(NHC)–Au(I) complexes with one side shaped 1,1'-biphenyl backbone have been prepared from chiral 6,6'-dimethoxybiphenyl-2,2'-diamine. The complexes were characterized by X-ray crystal structure diffraction. The Pd(II) complex showed good catalytic activities in the Suzuki–Miyaura and Heck–Mizoroki coupling reactions, and the (S)-Au(I) complexes also showed good catalytic activities in the asymmetric intramolecular hydroamination reaction to give the corresponding product in moderate ee.

scholarly journals Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

2013 ◽  
Vol 9 ◽  
pp. 2224-2232 ◽  
Author(s):  
Yin-wei Sun ◽  
Qin Xu ◽  
Min Shi
Keyword(s):  
Aromatic Ring ◽  
Functional Group ◽  
Phosphine Ligands ◽  
Gold Complexes ◽  
Hindered Rotation ◽  
X Ray ◽  
Catalytic Activities ◽  
Axially Chiral

Several novel chiral N-heterocyclic carbene and phosphine ligands were prepared from (S)-BINOL. Moreover, their ligated Au complexes were also successfully synthesized and characterized by X-ray crystal diffraction. A weak gold-π interaction between the Au atom and the aromatic ring in these gold complexes was identified. Furthermore, we confirmed the formation of a pair of diastereomeric isomers in NHC gold complexes bearing an axially chiral binaphthyl moiety derived from the hindered rotation around C–C and C–N bonds. In the asymmetric intramolecular hydroamination reaction most of these chiral Au(I) complexes showed good catalytic activities towards olefins tethered with a NHTs functional group to give the corresponding product in moderate yields and up to 29% ee.

scholarly journals Preparation of pyridine-3,4-diols, their crystal packing and their use as precursors for palladium-catalyzed cross-coupling reactions

2010 ◽  
Vol 6 ◽  
Author(s):  
Tilman Lechel ◽  
Irene Brüdgam ◽  
Hans-Ulrich Reissig
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Cross Coupling ◽  
Crystal Structure Analysis ◽  
Coupling Reactions ◽  
X Ray ◽  
Cross Coupling Reactions ◽  
Fluorescence Measurements ◽  
Subsequent Conversion ◽  
Palladium Catalyzed

A series of trifluoromethyl-substituted 3-alkoxypyridinol derivatives has been deprotected to furnish pyridine-3,4-diol derivatives in good yields. The X-ray crystal structure analysis proved that a 1:1 mixture of pyridine-3,4-diols and their pyridin-4-one tautomers exist in the solid state. Subsequent conversion into bis(perfluoroalkanesulfonate)s were smoothly achieved. The obtained compounds were used as substrates for palladium-catalyzed coupling reactions. Fluorescence measurements of the biscoupled products showed a maximum of emission in the violet region of the spectrum.

Geminal bis(hypersilyl) compounds — the synthesis and structure of bis[tris(trimethylsilyl)silyl]silanes

2000 ◽  
Vol 78 (11) ◽  
pp. 1399-1404
Author(s):  
Thoralf Gross ◽  
Helmut Reinke ◽  
Hartmut Oehme
Keyword(s):  
Crystal Structure ◽  
Key Words ◽  
Trifluoromethanesulfonic Acid ◽  
Molar Ratio ◽  
Coupling Reactions ◽  
Subsequent Reaction ◽  
X Ray ◽  
A Value ◽  
Spatial Demand

Protodesilylation of diphenylsilane with trifluoromethanesulfonic acid and subsequent reaction of the obtained bis(trifluoromethanesulfonyloxy)silane with tris(trimethylsilyl)silyllithium (1) (molar ratio 1:2) afforded bis[tris(trimethylsilyl)silyl]silane (8). Methyl-bis[tris(trimethylsilyl)silyl]silane (3) and phenyl-bis[tris(trimethylsilyl)silyl]silane (10) were obtained by coupling reactions of 1 with MeHSiCl2 or PhHSiCl2, respectively, (2:1). By treatment with HCBr3, the H-silanes 3, 8, and10 were converted into the bromosilanes [(Me3Si)3Si]2SiR1R2 (9: R1 = R2 = Br; 11: R1 = Me, R2 = Br; 12: R1 = Ph, R2 = Br). X-ray crystal structure analyses, performed for 3, 10 and 12, confirmed the expected distortions of the molecular skeletons of the compounds. Thus, e.g., in 10, the spatial demand of the two extended hemispherical hypersilyl groups forces a widening of the Si-Si-Si angle at the central Si atom to a value of 128.3°.Key words: silanes, sterically congested, bis(hypersilyl)silanes, hypersilylsilanes, bis(hypersilyl)germanes, tris(trimethylsilyl)silylsilanes.

Gold complexes with mono- or di-chalcogenides of bis(diphenylphosphino)methanide ligands. X-ray crystal structure of [Au(C6F5)2{(SPPh2)2C(AuAsPh3)2}]ClO4

Polyhedron ◽  
1998 ◽  
Vol 17 (11-12) ◽  
pp. 2029-2035 ◽  
Author(s):  
Beatriz Alvarez ◽  
Eduardo J. Fernández ◽  
M.Concepción Gimeno ◽  
Peter G. Jones ◽  
Antonio Laguna ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Gold Complexes ◽  
X Ray
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