Indium halides, catalysts

The recent emergence of indium halides as efficient Lewis acid catalysts presents new and exciting opportunities for indium chemistry ... 

In some cases, aUc5me hydrothiolation can be achieved in the absence of transition metal catalysts. Examples include the use of indium halides, selenium halides and salts, bases and p-cyclodextrin [215-226]. In particular, Cesium bases yield exclusively the anti-Markovnikov product and fi equently give high regioselectivity for the Z-linear olefin, which is complementary to transition metal catalysis. While these approaches as yet lack the generality of the transition metal-catalyzed systems, the ability to achieve hydrothiolation without the need for a metal catalyst is attractive. Undoubtedly, this area of research will continue to yield promising results. 

Reductive hromination of carboxylic acids to alkyl halides has been accomplished using 1,1,3,3-tetramethyldisiloxane (TMDS) and trimethyl-bromosilane (TMBS) in the presence of an indium tribromide catalyst. The reaction occurs in high yield in the presence of a variety of functionality [79]. 

Indium trichloride was identified as an efficient catalyst for the atom-transfer cyclization of allylic halides with an alkyne pendant [(42) (43)]. Mechanistic evidence... 

Acetyl ligands, in niobium complexes, C-H BDEs, 1, 298 Achiral phosphines, on polymer-supported peptides, 12, 698 Acid halides, indium compound reactions, 9, 683 Acidity, one-electron oxidized metal hydrides, 1, 294 Acid leaching, in organometallic stability studies, 12, 612 Acid-platinum rf-monoalkynes, interactions, 8, 641 Acrylate, polymerization with aluminum catalysts, 3, 280 Acrylic monomers, lanthanide-catalyzed polymerization,... 

The alkenylindium compounds, obtained by the addition of benzyl- and allylindium to alkynes, couple with organic halides in the presence of a palladium catalyst to give the three-component coupling products (Scheme 99).286 1,3-Dibromopropene or 3-bromo-l-iodopropene reacts with indium to give diindiopropene 87a,b.147,148 This dimetallic reagent reacts with two different electrophiles successively carbonyl compounds and imines are allowed to react with 87 as the first electrophile to give vinylic indium intermediates 88, which react with... 

Vinyl halides add to allylic amines in the presence of Ni(cod)2 where cod=l, 5-cyclooctodine, followed by reduction with sodium borohydride. Aryl iodides add to alkynes using a platinum complex in conjunction with a palladium catalyst. A palladium catalyst has been used alone for the same purpose, and the intramolecular addition of a arene to an aUcene was accomplished with a palladium or a GaCl3 catalyst, " AUcyl iodides add intramolecularly to aUcenes with a titanium catalyst, or to alkynes using indium metal and additives. The latter cyclization of aryl iodides to alkenes was accomplished with indium and iodine or with Sml2. " ... 

In the presence of excess acetyl halide and a tin(II) catalyst aromatic acetals react with allyltrimethylsilane to give a-allylbenzyl halides in good yield by double substitution of the acetal alkoxy groups (Scheme 10.127) [365]. The indium-catalyzed tandem reaction using a hydrosilane-allylsilane system enables deoxygenative allylation of aromatic ketones [366]. 

AUylation and propargylation reactions. In the presence of the (Ph3P)4Pd catalyst, indium(I) iodide form organoindium(III) reagents with allylic halides and propargylic mesylates that react with carbonyl compounds in various solvents. 

It is generally assumed that ions which can accelerate either or both partial reactions in a corrosion process are capable of being adsorbed on the iron surface. Thus it is known that hydrogen sulfide ions which accelerate both partial reactions of acid corrosion (although predominantly the anodic one), and formic acid molecules which catalyze the cathodic partial reaction but inhibit the anodic one, as well as commercial inhibitors which reduce both partial reactions, are in fact adsorbed on the iron surface. As a consequence the mere fact that adsorption takes place cannot be used to predict an expected change in corrosion rate as it is also known that halide ions cat-alize the anodic dissolution of indium, while hydroxyl adsorption catalyzes the anodic dissolution of iron. Furthermore, it is also known that certain ions can act either as a catalyst or an inhibitor when adsorbed on the metal surface depending on the type of metal considered. Kolotyrkin (18) observed that the adsorp-... 

In 2003 the first carbonylative coupling of indium reagents was reported both by Lee [90] and Sarandeses [91]. Asymmetrical ketones were produced by the carbonylative coupling of triaUtyl- and triarylindiums with aryl halides in the presence of a palladium catalyst under one bar of CO in THF at 66 °C (Scheme 4.50). 

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