Copper-Catalyzed Coupling of Triaryl- and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations

N-Heterocyclic Carbene Ligand-Controlled Chemodivergent Suzuki-Miyaura Cross Coupling

Two N-heterocyclic carbene ligands provide orthogonal chemoselectivity during the Pd-catalyzed Suzuki-Miyaura (SM) cross-coupling of chloroaryl triflates. The use of SIPr [SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene] leads to selective cross-coupling at chloride, while the use of SIMes [SIMes = 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene] provides selective coupling at triflate. With most chloroaryl triflates and arylboronic acids, ligand-controlled selectivity is high (≥10:1). The scope of this methodology is significantly more general than previously reported methods for selective SM coupling of chloroaryl triflates using phosphine ligands. Density functional theory studies suggest that palladium's ligation state during oxidative addition is different with SIMes compared to SIPr.

Triorganoindium Reagents in Rh-Catalyzed C⁻H Activation/C⁻C Cross-Coupling Reactions of 2-Arylpyridines

The activation of C–H bonds through catalytic reactions using transition metals is an important challenge in organic chemistry in which the intermediates are related to those produced in the classical cross-coupling reactions. As part of our research program devoted to the development of metal-catalyzed reactions using indium organometallics, a protocol for the C–H activation and C–C coupling of 2-arylpyridines with triorganoindium reagents under Rh(I) catalysis is reported. Under the optimized conditions, we found that Me₃In and Ar₃In reagents reacted with 2-arylpyridines and related compounds in the presence of Rh(PPh₃)₃Cl, in PhCl/THF (9:1), at 120 °C for 48 h, to afford the ortho-coupling products in moderate to good yields. The nitrogen atom in the pyridine ring acts as a directing group to assist the functionalization at the ortho position of the aryl group forming a new C–C bond at this position.

Copper-catalyzed cross-coupling of aryl-, primary alkyl-, and secondary alkylboranes with heteroaryl bromides

A method for the Cu-catalyzed cross-coupling of both aryl and alkylboranes with aryl bromides is described. The method employs an inexpensive Cu-catalyst and functions for a variety of heterocyclic as well as electron deficient aryl bromides. In addition, aryl iodides of varying substitution patterns and electronic properties work well.

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.

Sequential In-catalyzed intramolecular hydroarylation and Pd-catalyzed cross-coupling reactions using bromopropargyl aryl ethers and amines

A sequential one-pot In-catalyzed intramolecular hydroarylation and Pd-catalyzed cross-coupling reaction using bromopropargyl aryl ethers and amines has been developed.

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.

A phosphine-free, atom-efficient cross-coupling reaction of triorganoindiums with acyl chlorides catalyzed by immobilization of palladium(0) in MCM-41

The phosphine-free, atom-efficient cross-coupling of triorganoindiums with acyl chlorides has been achieved using a recyclable MCM-41-immobilized palladium(0)–Schiff base complex.

A phosphine-free, heterogeneous palladium-catalyzed atom-efficient carbonylative cross-coupling of triorganoindiums with aryl halides leading to unsymmetrical ketones

A phosphine-free heterogeneous palladium-catalyzed carbonylative cross-coupling of triorganoindiums with aryl halides for the synthesis of unsymmetrical ketones has been described.

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.

Pd-Catalyzed Ligand-Free Synthesis of Arylated Heteroaromatics by Coupling of N-Heteroaromatic Bromides with Iodobenzene Diacetate, Iodosobenzene, or Diphenyliodonium Salts

An efficient method for synthesizing arylated heteroaromatics has been reported via Pd-catalyzed ligand-free cross-coupling of N-heteroaromatic bromides with iodine(III) reagents under mild conditions. Iodobenzene diacetate, iodosobenzene, and diphenyliodonium salts act as ideal arylated sources in this reaction, producing bioactive aromatic-substituted pyridines and quinolines in moderate to high yields.

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

We report a Cu-catalyzed coupling between triarylaluminum reagents and alkyl halides to form arylalkanes. The reaction proceeds in the presence of N,N,N',N'-tetramethyl-o-phenylenediamine (NN-1) as a ligand in combination with CuI as a catalyst. This catalyst system enables the coupling of primary alkyl iodides and bromides with electron-neutral and electron-rich triarylaluminum reagents and affords the cross-coupled products in good to excellent yields.

Rapid threefold cross-couplings with sterically bulky triarylbismuths under Pd–Cu dual catalysis

The threefold cross-coupling reactivity of sterically highly demanding bulky triarylbismuths was addressed with task specific Pd–Cu dual catalytic conditions.

Copper-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides

An unprecedented Cu^I-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides is reported. Mechanistic studies with a Cp₂ZrAr₂ complex revealed that Cp₂Zr(Ar)(Cl) is the reactive species that undergoes transmetalation with (PN-1)CuI.

Copper-catalysed cross-couplings of arylboronate esters with aryl and heteroaryl iodides and bromides

Cu-catalysed cross-coupling for mono- and di-arylations of aryl and heteroaryl iodides and bromides is achieved with arylboronate esters.

Copper-catalysed cross-coupling: an untapped potential

Copper is emerging as a viable catalytic metal for cross-coupling reactions to construct carbon–carbon (C–C) bonds.