Palladium-catalyzed cross-coupling reaction of organoindiums with aryl halides in aqueous media

Metallic salt-catalyzed direct indium insertion into alkyl iodides and their applications in cross-coupling reactions

An efficient method for the synthesis of alkyl indium reagents via an indium(iii) or lead(ii) halide-catalyzed direct insertion of indium into alkyl iodides is developed. NMR and ESI-MS analyses indicated the formation of a mixture of an alkyl indium dihalide (RInX₂) and a dialkyl indium halide (R₂InX).

Efficient and sustainable laccase-catalyzed iodination ofp-substituted phenols using KI as iodine source and aerial O2as oxidant

The laccase-catalyzed iodination of p-hydroxyarylcarbonyl- and p-hydroxyarylcarboxylic acid derivatives using KI as iodine source and aerial oxygen as the oxidant delivers the corresponding iodophenols in a highly efficient and sustainable manner with yields up to 93% on a preparative scale under mild reaction conditions.

A new and sustainable laccase-catalyzed iodination of p-substituted phenols using KI as iodine source and aerial O₂ as oxidant has been developed.

Synthesis of bench-stable solid triorganoindium reagents and reactivity in palladium-catalyzed cross-coupling reactions

Triorganoindium reagents can be isolated as bench-stable solid R₃In(DMAP) complexes and show excellent reactivity in palladium-catalyzed cross-coupling reactions.

Transition metal-catalyzed cross-coupling reactions using organoindium reagents

This review highlights the versatility and significance of transition metal-catalyzed cross-coupling reactions employing mild and unique organoindium reagents with exceptional functional group compatibility and sometimes remarkable chemo- and stereoselectivities.

Transition-Metal-Free Cross-Coupling of Indium Organometallics with Chromene and Isochroman Acetals Mediated by BF3·OEt2

A transition-metal-free coupling of triorganoindium reagents with benzopyranyl acetals mediated by a Lewis acid has been developed. The reaction of R3In with chromene and isochroman acetals in the presence of BF3·OEt2 afforded 2-substituted chromenes and 1-substituted isochromans, respectively, in good yields. The reactions proceed with a variety of triorganoindium reagents (aryl, heteroaryl, alkynyl, alkenyl, alkyl) using only 50 mol % of the organometallic, thus demonstrating the efficiency of these species. Preliminary mechanistic studies indicate the formation of an oxocarbenium ion intermediate in the presence of the Lewis acid.

Direct access to 2-(hetero)arylated pyridines from 6-substituted 2-bromopyridines via phosphine-free palladium-catalyzed C–H bond arylations: the importance of the C6 substituent

A Pd(OAc)₂ catalyst promotes the arylation of heteroarenes with 6-substituted 2-bromopyridines, via C–H bond activation, providing straightforward access to 2-(hetero)arylpyridines.

Palladium-catalyzed cross-coupling of indium homoenolate with aryl halide with wide functional group compatibility

An efficient palladium-catalyzed cross-coupling of indium homoenolate with aryl halide is described. The reactions proceeded efficiently in DMA at 100 °C to afford the desired products of β-aryl ketones in moderate to good yields. Various important functional groups including COR, COOR, CHO, CN, OH, and NO(2) can be well tolerated in the protocol.

A sequential indium-mediated aldehyde allylation/palladium-catalyzed cross-coupling reaction in the synthesis of 2-deoxy-beta-C-aryl glycosides

Indium-mediated allylation of aldehydes with 2-chloro-3-iodopropene, followed by a palladium-catalyzed cross-coupling reaction with triarylindium reagents or arylboronic acids, leads to aryl-substituted homoallylic alcohols in good to excellent yields and diastereoselectivities. The products obtained from reactions conducted with d-glyceraldehyde acetonide can be transformed into 2-deoxy-beta-C-aryl ribofuranosides in high overall yields. Similarly, 2-deoxy-beta-C-aryl allopyranosides may be prepared efficiently from 2,4-O-benzylidene erythrose.

Synthesis of Aryliron Complexes [CpFe(CO)2Ar] by Palladium-Catalyzed Reactions of [CpFe(CO)2I] with Arylzinc, -Boron, or -Indium Reagents

Transmetalation between [CpFe(CO)₂I] and arylzinc iodide-lithium chloride complexes proceeds in the presence of catalytic amounts of palladium acetate and N,N,N’,N’-tetramethyl-1,2-cyclohexanediamine to yield the corresponding aryliron complexes [CpFe(CO)₂Ar]. Phenylation of [CpFe(CO)₂I] also takes place when triphenylindium is used under similar conditions. Arylboronic acids undergo arylation in the presence of cesium carbonate and a palladium-N-heterocyclic carbene complex, PEPPSI.  The present methods are useful for the facile synthesis of various functionalized [CpFe(CO)₂Ar]. The products [CpFe(CO)₂Ar] represent an interesting class of aryl metals that undergo several transformation.

LiCl-mediated preparation of functionalized benzylic indium(III) halides and highly chemoselective palladium-catalyzed cross-coupling in a protic cosolvent

Sensitive functional groups such as COR, CHO, or CH(2)OH can be present in benzylic indium reagents prepared by the direct insertion of indium in the presence of LiCl. These reagents undergo palladium-catalyzed cross-coupling reactions in the presence of a protic cosolvent after activation with iPrMgCl x LiCl (see scheme). Remarkable chemoselectivities are achieved by using various electrophiles containing NH or OH groups.

Palladium-catalyzed reactions of arylindium reagents prepared directly from aryl iodides and indium metal

Treatment of aryl iodides with indium metal in the presence of lithium chloride leads to the formation of an organoindium reagent capable of participating in cross-coupling reactions under transition-metal catalysis. Combination with aryl halides in the presence of 5 mol % Cl2Pd(dppf) furnishes biaryl compounds in good yields; similarly, reaction with acyl halides or allylic acetates/carbonates in the presence of 5-10 mol % palladium catalyst leads to arylketones and allylic substitution products, respectively, in moderate yields. The reactions are tolerant of the presence of protic solvents, and approximately 85% of the indium metal employed can be recovered by reduction of the residual indium salts with zinc(0).