110320-16-6Relevant academic research and scientific papers
The course of oxidative addition reactions of haloalkynes and haloalkenes to dimethyl- and dialkynylaurate(I) anions [RAuR]-
Schuster, Oliver,Schmidbaur, Hubert
, p. 3769 - 3775 (2008/10/09)
The reactions of halo-alkynes Cl-C{triple bond, long}CH, C-lC{triple bond, long}C-Cl or PhC{triple bond, long}C-I with solutions of Li+[MeAuMe]- in diethylether containing Ph3P do not give the expected oxidative addition products Me2(RC{triple bond, long}C)Au(PPh3) with R = H, Cl, Ph. A mixture of other complexes is obtained instead which are generated in secondary reactions involving reductive elimination of ethane and/or dialkyne. However, addition of the halo-alkene H(Cl)C{double bond, long}CCl2 to the same substrate solution affords trans-Me2[trans-H(Cl)C{double bond, long}C(Cl)]Au(PPh3) in good yield. Its molecular structure with pseudo-Cs symmetry has been determined by the solution NMR spectra and a single-crystal X-ray diffraction study. The reaction of methyl iodide with solutions of Li+[RC{triple bond, long}CAuC{triple bond, long}CR]- in diethylether containing PPh3 give the quaternary salts Ph3PMe+ [RC{triple bond, long}CAuC{triple bond, long}CR]- as the main products and only small amounts of cis-Me2(RC{triple bond, long}C)Au(PPh3) complexes probably formed in a series of oxidative addition, reductive elimination, and substitution reactions. The structure of Ph3PMe+ [PhC{triple bond, long}CAuC{triple bond, long}CPh]- has been determined.
Preparation, structure and decomposition of gold(I) and gold(III) acetylide complexes
Schuster, Oliver,Liau, Ruei-Yang,Schier, Annette,Schmidbaur, Hubert
, p. 1429 - 1441 (2008/10/09)
1-Alkynyl-dimethyl(triorganophosphine)gold(III) complexes of the type cis-Me2(Ph3P)Au-C≡C-R with R = H, Me, Ph (1-3) have been prepared from the cis-Me2(Ph3P)AuX (X = Cl, I) complexes and lithium alkynyls. The crystal structures of 1 and 2 have been determined together with those of the reference compounds cis-Me 2(Ph3P)AuX (X = Cl, I) and cis-Me2(Me 3P)AuI. The molecules have a standard square planar geometry and are not associated into oligomers. Due to the different hybridization of the carbon orbitals, the Au-C(≡CR) bonds are found significantly shorter than the Au-CH3 bonds. Compounds 1-3 are stable colourless, crystalline solids at 20°C but decompose on heating with selective (cis) reductive elimination of ethane and formation of the gold(I) alkynyls (Ph3P)Au-C≡C-R thus retaining the stronger gold-alkynyl bonds. Two complexes of this type have also been prepared by conventional routes from (R3P)AuX complexes and the crystal structures of (Me3P)Au-C≡C-Ph and [(p-Tol) 3P]Au-C≡C-H have been determined. The former with the small Me3P ligand is associated into two different trimers via aurophilic bonding and further aggregated into chains via weak inter-trimer contacts, while the latter is a monomer owing to the steric bulk of the (p-Tol)3P ligand.
Synthesis, Structure, and Reactivities of cis-Dimethyl(η1-allyl)gold(III) Complex. Diastereoselective Allylation of Aromatic Aldehyde
Sone, Takuo,Ozaki, Satoshi,Kasuga, Noriko C.,Fukuoka, Atsushi,Komiya, Sanshiro
, p. 1523 - 1534 (2007/10/03)
cis-Dimethyl(η1-allyl)(triphenylphosphine)gold(III), cis-1-allyl)(PPh3)> (η1-allyl = allyl (1), crotyl (2), methallyl (3)) has been synthesized by reaction of cis- (X = I, NO3) with corresponding Grignard reagents.X-Ray structure analysis of 2 shows that 2 has a typical square planar cis configuration and the crotyl ligand binds to Au by η1-mode: orthorhombic, space group P212121, a = 9.816(2), b = 23.208(4), c = 9.5290(9) Angstroem, Z = 4, R(Rw) = 0.037(0.041) with use of 2551 reflections.Reactions of 2 with HCl and Br2 selectively give 1-butene and 3-bromo-1-butene, respectively, indicating γ-regioselectivity of the reactions.Compounds 1-3 react with aldehydes and ketones to give the corresponding homoallyl alcohols.C-C bond formation also takes place at the γ-position of η1-allyl moiety selectively.The rate of the allylation reaction of carbonyl compounds decreases in the order of methallyl (3) > allyl (1) > crotyl (2) gold(III) complexes.The homoallyl alcohol formed by the reaction of 2 with benzaldehyde is a diastereoisomeric mixture of 2-methyl-1-phenyl-3-buten-1-ol, with high anti selectivity.Both the reaction rate and anti selectivity in the allylation reaction were reduced by addition of tertiary phosphines such as PPh3 and PCy3, and a 6-membered transition state has been proposed, which indicates coordination of the carbonyl group to a T-shape Au intermediate produced by dissociation of the PPh3 ligand.
