Indium methyl

An X-ray diffraction study indicates that [Me2AsInMe2]3 contains two independent molecules per asymmetric unit in the solid state, one with a planar (Asln)3 ring while the other is puckered. However, a dynamic H NMR study indicates equivalence of the indium methyls and of the arsenic methyls in solution down to -80 °C. [(t-Bu)2AsInMe2]2 is dimeric by X-ray and mass spectral studies and the (Asln)2 core is planar. 

The conventional electrochemical reduction of carbon dioxide tends to give formic acid as the major product, which can be obtained with a 90% current efficiency using, for example, indium, tin, or mercury cathodes. Being able to convert CO2 initially to formates or formaldehyde is in itself significant. In our direct oxidation liquid feed fuel cell, varied oxygenates such as formaldehyde, formic acid and methyl formate, dimethoxymethane, trimethoxymethane, trioxane, and dimethyl carbonate are all useful fuels. At the same time, they can also be readily reduced further to methyl alcohol by varied chemical or enzymatic processes. 

Indium trichloride [30] and methylrhenium trioxide [31] catalyze the aqueous Diels-Alder reaction of acrolein and acrylates with cyclic and open-chain dienes. Some examples of the cycloaddition of methyl vinyl ketone with 1,3-cyclohexadiene are reported in Scheme 6.18. MeReOs does not give satisfactory yields for acroleins and methyl vinyl ketones with substituents at the jS-position and favors the self-Diels-Alder reaction of diene. 

Although not formally the enamine synthesis, reaction of an enamine with methyl hromoacetate in the presence of indium metal leads to a-aUcylation R2N-CH=CHR R2N-CH(R )CHR. ... 

Recently, on the basis of the Markovnikov addition of water to alkynes, Trost et al. developed a three-component addition reaction of terminal alkynes, water, and methyl vinyl ketone, affording 1,5-diketones in DMF/water in the presence of ruthenium and indium catalysts (Eq. 4.38). 

In 1991, Li and Chan reported the use of indium to mediate Barbier-Grignard-type reactions in water (Eq. 8.49).108 When the allylation was mediated by indium in water, the reaction went smoothly at room temperature without any promoter, whereas the use of zinc and tin usually requires acid catalysis, heat, or sonication. The mildness of the reaction conditions makes it possible to use the indium method to allylate a methyl ketone in the presence of an acid-sensitive acetal functional group (Eq. 8.50). Furthermore, the coupling of ethyl 2-(bromomethyl)acrylate with carbonyl compounds proceeds equally well under the same reaction conditions, giving ready access to various hydroxyl acids including, for example, sialic acids. 

Indium-mediated allylation of an unreactive halide with an aldehyde132 was used to synthesize an advanced intermediate in the synthesis of antillatoxin,133 a marine cyanobacteria (Lyngbya majus-cula) that is one of the most ichthyotoxic compounds isolated from a marine plant to date. In the presence of a lanthanide triflate, the indium-mediated allylation of Z-2-bromocrotyl chloride and aldehyde in saturated NH4C1 under sonication yielded the desired advanced intermediate as a 1 1 mixture of diastereomers in 70% yield. Loh et al.134 then changed the halide compound to methyl (Z)-2-(bromomethyl)-2-butenoate and coupled it with aldehyde under the same conditions to yield the desired homoallylic alcohol in 80% yield with a high 93 7 syn anti selectivity (Eq. 8.55). 

A new method has been developed for the synthesis of ( )-3-methyl Baylis-Hillman-type adducts with high E/Z (>93%) selectivity in modest to good yields. The process consists of two steps an indium-mediated allylation reaction and a simple base-catalyzed isomerization step (Eq. 8.61). Various aldehydes were allylated with allyl bromides using indium under very mild conditions in aqueous media and thus converted to the Baylis-Hillman-type adducts.150... 

Clerici and Porta reported that phenyl, acetyl and methyl radicals add to the Ca atom of the iminium ion, PhN+Me=CHMe, formed in situ by the titanium-catalyzed condensation of /V-methylanilinc with acetaldehyde to give PhNMeCHMePh, PhNMeCHMeAc, and PhNMeCHMe2 in 80% overall yield.83 Recently, Miyabe and co-workers studied the addition of various alkyl radicals to imine derivatives. Alkyl radicals generated from alkyl iodide and triethylborane were added to imine derivatives such as oxime ethers, hydrazones, and nitrones in an aqueous medium.84 The reaction also proceeds on solid support.85 A-sulfonylimines are also effective under such reaction conditions.86 Indium is also effective as the mediator (Eq. 11.49).87 A tandem radical addition-cyclization reaction of oxime ether and hydrazone was also developed (Eq. 11.50).88 Li and co-workers reported the synthesis of a-amino acid derivatives and amines via the addition of simple alkyl halides to imines and enamides mediated by zinc in water (Eq. 11.51).89 The zinc-mediated radical reaction of the hydrazone bearing a chiral camphorsultam provided the corresponding alkylated products with good diastereoselectivities that can be converted into enantiomerically pure a-amino acids (Eq. 11.52).90... 

The electrochemistry of Mb has been achieved by using mercury electrodes [93], methyl-viologen-modified gold electrodes [94], and ultraclean and hydrophilic indium... 

Fig. 5. The Arrhenius plot of kl/k2i. e, dimethyl zinc O, trimethyl gallium , trimethyl indium. % figures are in terms of the theoretical yield of methyl radicals that would be obtained if all methyl-metal bonds were broken. All points are corrected to 13 torr pressure (toluene+0.3-2.5 % alkyl).

Lithium alkylamides react with dimethyltin dichloride to give the cyclotristannazane, which is methylated by trimethyl-aluminum, -gallium, or -indium, giving the metal stannylamides, which are coordinatively dimerized (Equation (167)).503... 

With a ruthenium promoter (added as [Ru(CO)4l2]), r(CO) bands due to Ru iodo-carbonyls dominated the spectrum, precluding the easy observation of iridium species. Before injection of the Ir catalyst, absorptions due to [Ru(CO)2l2(sol)2], [Ru(CO)3l2(sol)] and [Ru(CO)3l3] are present. After injection of the iridium catalyst (Ru Ir = 2 1), [Ru(CO)3l3] becomes the dominant Ru species (Figure 3.11(b)). The observations indicate that the Ru(II) promoter has a high affinity for iodide and scavenges Hl(aq) as H30 [Ru(CO)3l3] . An indium promoter is believed to behave in a similar manner to form H30 [Inl4] . These promoter species also catalyse the reaction of Hlj q) with methyl acetate (Eq. (3)), which is an important organic step in the overall process. 

The reduction of /3-nitrostyrenes with indium metal in aqueous ammonium chloride gave a mixture of E and Z isomers while the reduction of -methyl-/ -nitrostyrenes with indium powder in the presence of trimethylsilyl chloride gave exclusively the E isomer. 

The indium nonaflate (In(ONf)3)-catalyzed annulation of 2-thienyl- and 2-furylindoles, bithiophenes, and bifurans with methyl propargyl ether also provides tetracyclic heteroaryl annulated [ ]carbazoles in moderate to good yields <2005AGE1336> (Equation (104) Table 10). 

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