Sodium tetrachloroaurate .dihydrate

Che has reported the tandem hydroamination/hydroarylation of aromatic amines wirh terminal alkynes to form dihydroquinolines in which 1 equiv of aniline combines with 2 equiv of alkyne [23]. For example, reaction of 3-methoxyanilme with pheny-lacetylene (5 equiv) and a catalytic 1 1 mixture of the gold(I) N-heterocydic carbene complex (IPr)AuCl (IPr= l,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidine) and AgOTf at 150 °C under microwave irradiation led to isolation of dihydroquinoline 21 in 82 % yield (Eq. (11.15)). Alternatively, reaction of o-acetylaniline with pheny-lacetylene catalyzed by a mixture of (IPr)AuCl and AgOTf at 150 °C led to isolation of the quinoline derivative 22 in 93% yield via incorporation of a single equivalent of alkyne (Eq. (11.16)). Arcadi has reported the gold(IlI)-catalyzed hydroamination/ hydroarylation of 2-alkynylanilines with a,p-enones to form C3-alkyl indoles [24]. As an example of this transformation, treatment of 2-(phenylethynyl)aniline with 4-phenyl-3-buten-2-one and a catalytic amount of sodium tetrachloroaurate dihydrate in ethanol at 30°C formed 1,2,3-trisubstituted indole 23 in 88% yield (Eq. (11.17)). 

Sodium tetrachloroaurate(HI) dihydrate (0.397 g, 1.0 mmole) is dissolved in water (10 mL), and the solution is cooled in ice. To this solution is added the thiodiglycol (0.366 g, 3.0 mmoles), undiluted, with stirring. This addition must be made very slowly (45 minutes) and may be stopped when the yellow color of the solution is discharged. A solution of the ligand, 4-ethylbenzenethiol (0.140 g, 1.0 mmole), in chloroform (20 mL) is added dropwise with stirring over 20 minutes. The chloroform layer is separated and added dropwise to methanol (40 mL), and the pale yellow complex, 4-ethylbenzenethiolatogold(I) (0.33 g, 98%), precipitates. The product is filtered, washed with methanol, and dried... 

Sodium tetrachloroaurate(lll) dihydrate NaAuCl4-2H30 13874-02-7 397.800 oran-yel rhom cry 100 dec 160 s FtOH, eth... 

Gold(III) chloride (0.33m for gold). Dissolve 13.3 g sodium tetrachloroaurate(III) dihydrate, NaAuC -2H20, in water and dilute to 100ml. Alternatively, dissolve 6.57 g gold metal in 50 ml aqua regia, evaporate the solution to dryness, and dissolve the residue in 100 ml water. 

Utimoto has also shown that simple gold(III) salts catalyze the intramolecular hydroamination of alkynes with arylamines [4]. For example, treatment of 2-(3,3-dimethyl-l.butynyl)aniline with a catalytic amount of sodium tetrachloroaurate in refluxing TH F for 30 min led to isolation of 2-f-butylindole in 90% yield (Eq. (11.3)). Marinelli has modified and expanded the scope of Utimoto s procedure through employment of ethanol, ethanol/water [5], or ionic liquids 6] solvents. As an example of this modified protocol, treatment of 2-alkynylaniline 2 with a catalytic amount of NaAuCU dihydrate in ethanol at room temperature for 6h led to isolation of 2-(4-chlorophenyl)indole 3 in 92% yield (Eq. (11.4)). A similar hydroamination protocol employing AUCI3 as a catalyst has been recently reported by Majumdar [7]. 

Synthesis of the metallic Au cores began with the treatment of all glassware with aqua regia (3 1 HChHNOs) followed by a thorough rinse with ultrapure water (18.2 M 2 cm ) from a Millipore academic system. A 1 mM aqueous solution of hydrogen tetrachloroaurate(III) (0.2 g in 0.5 L water) was placed in a roundbottom flask equipped with a reflux condenser. After the solution was brought to a boil, 39 mM sodium citrate dihydrate (1.15 g in 100 mL water) was added through the top of the condenser and the solution was allowed to boil for 10 minutes. 

The reaction of 5,10,15,20-tetraphenyl-p-benziporphyrin, sodium tetrachloroaurate(iii) dihydrate, and potassium carbonate in dichloro-methane, carried out by Szyszko et yielded gold(in) 5,10,15,20-tet-raphenyl-21-carbaporphyrin owing to the contraction of p-phenylene to cyclopentadiene. This molecule is the very first representative of a true 5,10,15,20-tetraphenyl-21-carbaporphyrin complex where four trigonal donor atoms are involved in equatorial coordination. The NMR spectrum of this Au complex resembles the basic pattern of aromatic carbaporphyrinoids with an AB spin system at d = 8.78, H(7,18), and 8.67 ppm, H(8,17) with a coupling, /hh of 4.9 Hz, which is typical of the pyrrole ring in porphyrinoids. 

Hydrogen tetrachloroaurate (HAuCLi, 99%), trisodium citrate dihydrated (Cit), ferric chloride (FeCl3), sodium hydroxide (NaOH, 98%), hydrochloric acid (HCl, a 37%),... 

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