Reaction Of Iodide Research Articles

Transition‐Metal‐Free Carbonylative Suzuki‐Miyaura Reactions of Aryl Iodides with Arylboronic Acids Using N‐Formylsaccharin as CO Surrogate

AbstractUnprecedented, high yielding, transition‐metal‐free carbonylative Suzuki‐Miyaura reactions of aryl iodides with arylboronic acids using N‐formylsaccharin as CO surrogate have been developed. Notably, this general protocol was adapted to the synthesis of the triglyceride and cholesterol regulator drug, fenofibrate, and carbon‐13 labeled biaryl ketone.magnified image

Heterochiral Doped Supramolecular Coordination Networks for High-Performance Optoelectronics.

Chiral self-sorting has great potential for constructing new complex structures and determining chirality-dependent properties in multicomponent mixtures. However, it is still of great challenge to achieve high fidelity chiral self-discrimination. Besides, the researches on the coordination polymers or metal-organic frameworks for micro/nanooptoelectronics are still rare due to their low conductivity and difficulty in developing a rapid and simple scale-up synthetic method. Here, heterochiral supramolecular coordination networks (SCNs) were synthesized by the solvothermal reaction of naphthalene diimide enantiomers and cadmium iodide, using the chirality as a synthetic tuning parameter to control the morphologies. Intriguingly, heterochiral micro/nanocrystals exhibited photochromic and photodetecting properties. Furthermore, we also developed a simple and efficient doping method to enhance the conductivity and photoresponsivity of micro/nanocrystals using hydrazine. From experimental and theoretical studies, the mechanism was suggested as follows: the radicals in the singly occupied molecular orbital level of the ligands provide charge carriers that can undergo "through-space" transport between π-π stacked ligands and the electron transfer from adsorbed hydrazine to the SCNs results in reduction of energy gap, leading to increased conductivity. Our findings demonstrate a simple and powerful strategy for implementing coordination networks with redox ligands for micro/nanooptoelectronic applications.

DFT Study on the Mechanism of Palladium(0)-Catalyzed Reaction of Aryl Iodides, Norbornene, and Di-tert-butyldiaziridinone

The reaction mechanism of palladium(0)-catalyzed reaction of aryl iodides, norbornene, and di-tert-butyldiaziridinone has been studied theoretically. Two reaction mechanisms were calculated. The re...

1,10-Phenanthroline- or Electron-Promoted Cyanation of Aryl Iodides

A 1,10-phenanthroline-promoted cyanation of aryl iodides has been developed. 1,10-Phenanthroline worked as an organocatalyst for the reaction of aryl iodides with tetraalkylammonium cyanide to afford aryl cyanides. A similar reaction occurred through an electroreductive process.

A Regioselective Approach to C3-Aroylcoumarins via Cobalt-Catalyzed­ C(sp2)–H Activation Carbonylation of Coumarins

A new cobalt-catalyzed C–H bond activation of coumarins with aryl halides or pseudohalides and carbon monoxide insertion to give various 3-aroylcoumarin derivatives is described. It is the first time that CO as C1 feedstock is used as the coupling partners in cobalt-catalyzed regioselective coumarin C–H functionalization reactions. Upon activation with manganese powder, the Co catalyzes the C–H bond activation carbonylation reactions of aryl iodides, bromides, and even triflates under mild conditions, providing the regioselective aroylated products in moderate to good yields.

Transition-Metal (Pd, Ni, Mn)-Catalyzed C-C Bond Constructions Involving Unactivated Alkyl Halides and Fundamental Synthetic Building Blocks.

The catalytic construction of C-C bonds between organohalide or pseudohalide electrophiles and fundamental building blocks such as alkenes, arenes, or CO are widely utilized metal-catalyzed processes. The use of simple, widely available unactivated alkyl halides in these catalytic transformations has significantly lagged behind the use of aryl or vinyl electrophiles. This difference is primarily due to the relative difficulty of activating alkyl halides with transition metals under mild conditions. This Account details our group's work toward developing a general catalytic manifold for the construction of C-C bonds using unactivated alkyl halides and a range of simple chemical feedstocks. Critical to the strategy was the implementation of new modes of hybrid organometallic-radical reactivity in catalysis. Generation of carbon-centered radicals from alkyl halides using transition metals offers a solution to challenges associated with the application of alkyl electrophiles in classical two-electron reaction modes. A major focus of this work was the development of general palladium-catalyzed carbocyclizations and intermolecular cross-couplings of unactivated alkyl halides (alkyl-Mizoroki-Heck-type reactions). Initial studies centered on the use of alkyl iodides in these processes, but subsequent studies determined that the use of an electron-rich ferrocenyl bisphosphine (dtbpf) enables the palladium-catalyzed carbocyclizations of unactivated alkyl bromides. Mechanistic studies of these reactions revealed interesting details regarding a difference in mechanism between reactions of alkyl iodides and alkyl bromides in carbocyclizations. These studies were consistent with alkyl bromides reacting via an autotandem catalytic process involving atom-transfer radical cyclization (ATRC) followed by catalytic dehydrohalogenation. Reactions of alkyl iodides, on the other hand, involved metal-initiated radical chain pathways. Recent studies have expanded the scope of alkyl-Mizoroki-Heck-type reactions to the use of a first-row transition metal. Inexpensive nickel precatalysts, in combination with the bisphosphine ligand Xantphos, efficiently activate alkyl bromides for both intra- and intermolecular C-C bond-forming reactions. The reaction scope is similar to the palladium-catalyzed system, but in addition, alkene regioisomeric ratios are dramatically improved over those in reactions with palladium, solving one of the drawbacks of our previous work. Initial mechanistic studies were consistent with a hybrid organometallic-radical mechanism for the nickel-catalyzed reactions. The novel reactivity of the palladium catalysts in the alkyl-Mizoroki-Heck-type reactions have also paved the way for the development of other C-C bond-forming processes of unactivated alkyl halides, including aromatic C-H alkylations as well as low-pressure alkoxycarbonylations. Related hybrid organometallic-radical reactivity of manganese has led to an alkene dicarbofunctionalization using alkyl iodides.

Copper-Catalyzed Three-Component Coupling Reaction of Aryl Iodides, a Disilathiane, and Alkyl Benzoates Leading to a One-Pot Synthesis of Alkyl Aryl Sulfides

A copper-catalyzed three-component coupling reaction of aryl iodides, hexamethyldisilathiane and alkyl benzoates leading to alkyl aryl sulfides has been demonstrated. A disilathiane acted as both a sulfur source and a promoter of the sulfidation, and the alkyl moiety of the alkyl benzoate was effectively introduced on one side of the sulfide. Moreover, we found that the protocol can be expanded to the preparation of ethyl phenyl selenide with diphenyl diselenide.

Production and Application of Highly Efficient and Reusable Palladium Nanocatalyst Decorated on the Magnetically Retrievable Chitosan/Activated Carbon Composite Microcapsules

This study reports (i) the production of magnetically retrievable microcapsules as immobilizing agents, which are composed of chitosan/activated carbon composite (CS-AC/Fe3O4), (ii) the green synthesis of highly stable palladium nanoparticles on CS-AC/Fe3O4 without using any toxic reducing agents (Pd NPs@CS-AC/Fe3O4), (iii) the investigation of catalytic behavior of Pd NPs@CS-AC/Fe3O4 in Suzuki–Miyaura reactions of different aryl iodides, bromides, and chlorides, and (iv) the examination of recoverability and reusability of Pd NPs@CS-AC/Fe3O4. The characterization of Pd NPs@CS-AC/Fe3O4 was performed by FT-IR, TG/DTG, XRD, SEM, and EDS analyses. It was found that the average sizes of palladium nanoparticles were changed in the range of 31–48 nm. The catalytic tests revealed that Pd NPs@CS-AC/Fe3O4 was a very effective catalyst against synthesis of various biaryl compounds via Suzuki–Miyaura reactions, by giving high reaction yields under mild reaction conditions. Furthermore, it was found that Pd NPs@CS-AC/Fe3O4 was a highly retrievable and practical nanocatalyst due to its reusable nature. Pd NPs@CS-AC/Fe3O4 gave 95% of yield after ten successive cycles. These results show that Pd NPs@CS-AC/Fe3O4 is a superb catalyst and it can be applied in different catalytic systems or industrial applications due to the fact that it offers notable advantages such as high catalytic performance, reusability, stability, excellent functional group tolerance, wide substrate scope, and simple separation.

Cobalt, nickel and iron embedded chitosan microparticles as efficient and reusable catalysts for Heck cross-coupling reactions.

Cobalt, nickel and iron are efficient catalysts for numerous chemical and biological reactions, but they are hardly immobilized on solid matrixes due to their relatively weak chelation with the surface molecules. We have employed a co-electrospraying coupling with glutaraldehyde cross-linking technique to prepare cobalt (Co2+), nickel (Ni2+) and iron (Fe2+) catalyst embedded chitosan microparticles (M@MicroCS) (M = Co, Ni and Fe). The Co@MicroCS beads exhibited excellent catalytic activity for the Heck cross-coupling reactions of aromatic iodides with alkenes. Moreover, the Co@MicroCS bead catalyst could be even reused at least for five times without significant loss of the catalytic activities. The average diameter of the free volume holes for the porous Co@MicroCS beads was determined to be much larger than the size of the reactant and product molecules, allowing them to freely migrate through the catalytic sites inside the chitosan beads. These results clearly indicate that the Heck reactions catalyzed by the Co@MicroCS beads primarily occurs inside the porous chitosan beads. Taken together, we have demonstrated a straightforward approach to prepare efficient and recyclable heterogeneous catalysts derived from the first-row transition metal catalysts by entrapping them inside the chitosan microparticles.

Palladium-Catalyzed Regio- and Stereoselective Synthesis of (E)-1,3-Bissilyl-6-arylfulvenes from Aryl Iodides and Silylacetylenes

An efficient synthetic route to ( E)-1,3-bissilyl-6-arylfulvenes has been developed. The reaction of aryl iodides with trimethylsilylacetylene in the presence of a catalytic amount of PdBr2 gives 6-aryl-1,3-bis(trimethylsilyl)fulvenes in good to excellent yields with complete regio- and stereoselectivity. The reaction involves trimerization of trimethylsilylacetylene and cleavage of one silyl group. The silylated fulvenes obtained could be converted into halogenated fulvenes by site-selective halodesilylation. The halogenated fulvenes underwent the Stille coupling leading to the corresponding arylated fulvenes.

Pd-Catalyzed Alkyne Insertion/C-H Activation/[4 + 2] Carboannulation of Alkenes to the Synthesis of Polycyclics.

An unprecedented Pd-catalyzed alkyne insertion/C-H activation/intramolecular [4 + 2] carboannulation of alkenes has been reported. In this transformation, the C-H activation was triggered by an in situ generated alkenylpalladium species via the Pd-catalyzed cross-coupling reaction of aryl iodides and alkynes. Subsequently, the resulting five-membered C, C-palladacycle intermediates were added across the alkenes, providing a unique approach to access diversified polycyclics in good efficiency. Two new rings and three C-C bonds were formed in one pot.

Iron(II)-Catalyzed Heck-Type Coupling of Vinylarenes with Alkyl Iodides.

An iron(II)-catalyzed radical alkyl Heck-type reaction of alkyl iodides with vinylarenes under mild conditions has been reported. t-Butyl peroxybenzoate (TBPB) behaves simultaneously as a radical relay initiator, a precursor for the generation of alkyl radical from alkyl iodides, and an oxidant to recycle iron(II)/iron(III). Unactivated primary, secondary, and tertiary alkyl iodides are compatible with the reaction conditions. The mechanistic studies suggest that a radical-polar-crossover pathway might be involved in the catalytic cycle.

Oxidative Aminoarylselenation of Maleimides via Copper-Catalyzed Four-Component Cross-Coupling.

The first example of copper-catalyzed four-component coupling reaction of aryl iodides, Se powder, secondary amines, and maleimides is developed. This reaction provides an efficient and concise route to access aminoarylselenated maleimides via double C-Se bonds and C-N bond formation. The appealing features of this transformation are the use of Se powder as a selenating reagent, a green catalytic system, a wide range of substrate scope, and late-stage selenation of bioactive compounds.

Palladium-catalyzed reductive Heck reaction of α,β-unsaturated alkenes and cycloalkyl iodides

The palladium catalyzed reductive Heck reactions of unactivated cycloalkyl iodides with α,β-unsaturated alkenes have been developed. A number of hydrocycloalkylated alkenes were obtained in reasonable yields under the optimized conditions. The obvious advantage of this approach is that the hydride source was provided by Et3N and no other reductant or base was required in the reaction.

Copper-catalyzed radical approach to allenyl iodides.

A copper-catalyzed 1,4-addition reaction of sulfonyl iodides with 1,3-enynes affording various allenyl halides in high yields under mild conditions has been developed. Mechanistic studies showed that the reaction proceeds through a radical mechanism.

Synthesis of a two-dimensional organic-inorganic bismuth iodide metalate through in situ formation of iminium cations.

(Me2C[double bond, length as m-dash]NMe2)Bi2I7 represents a new layered organic-inorganic iodido bismuthate. It displays an unprecedented anion topology, a low band gap and good stability. Advanced electronic structure analysis finds the II interactions to be decisive for the compound's structural and electronic properties.

Synthesis of fluorenyl alcohols via cooperative palladium/norbornene catalysis.

Herein, we report a novel catalytic synthesis of substituted 9H-fluoren-9-ols starting from aryl iodides and secondary ortho-bromobenzyl alcohols in the presence of palladium/norbornene as a catalytic system. The present protocol exhibits high functional group tolerance, mild reaction conditions and moderate to good yields. This transformation is based on two sequential pathways: (i) Pd(ii)-mediated oxidation of the secondary alcohol to the corresponding ketone and (ii) Pd(0)/norbornene-catalyzed reaction of the in situ generated ortho-bromoacetophenone with the aryl iodide.

Pd/P/dba-Promoted cascade annulations to produce fused medium-sized sulfoximine polyheterocycles

The Pd-catalyzed multicomponent reactions of NH-sulfoximine, aryl iodide and norbornadiene (NBD) are reported to chemoselectively produce fused medium-sized sulfoximine polyheterocycles in good to excellent yields.

A diversity of alkylation/acylation products of uracil and its derivatives: synthesis and a structural study.

tert-Butyl dicarbonate (Boc2O) and ethyl iodide (EtI) reactions with uracil (U), thymine (T) and 6-methyluracil (6-MU) were performed following routine procedures in pyridine/DMF solvents and with DMAP as the catalyst. Among 20 synthesized compounds, a derivative of 6-methyluracil substituted by the Boc-pyridine moiety at the C5 position appeared unexpectedly. The NMR spectra confirmed the molecular structure of all uracil derivatives. Parallel quantum mechanical DFT calculations supported the experimental findings.

Palladium-Catalyzed Three-Component Reaction of Dihydrosilanes and Vinyl Iodides in the Presence of Alcohols: Rapid Assembly of Silyl Ethers of Tertiary Silanes.

A one-pot reaction that directly converts dihydrosilanes into silyl ethers of tertiary silanes is reported. Under palladium catalysis, one Si-H bond of the dihydrosilane formally engages in C(sp3 )-Si bond formation with a vinyl iodide while the other Si-H bond is transformed into a silyl iodide that undergoes facile alcoholysis with an alcohol. The C-C double bond is reduced in that process. This three-component reaction provides in a single synthetic operation an access to silyl ethers of functionalized and hindered alcohols. Several of those would otherwise be difficult to make but the intermediacy of a highly reactive silyl iodide even allows for tert-butanol to react at room temperature.