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Oxidative addition represents a critical elementary step in myriad catalytic transformations. Here, the importance of thoughtful ligand design cannot be overstated. In this work, we report the intermolecular activation of iodobenzene (PhI) at a coordinatively saturated 18-electron [Ni 0(diphosphine) 2] complex bearing a Lewis acidic secondary coordination sphere. Whereas alkyl-substituted diphosphine complexes of Group 10 are known to be unreactive in such reactions, we show that [Ni 0(P 2B Cy 4) 2] (P 2B Cy 4=1,2-bis(di(3-dicyclohexylboraneyl)-propylphosphino)ethane) is competent for room-temperature PhI cleavage to give [Ni II(P 2B Cy 4)(Ph)(I)]. This difference in oxidative addition reactivity has been scrutinized computationally – an outcome that is borne out in ring-opening to provide the reactive precursor – for [Ni 0(P 2B Cy 4) 2], a “boron-trapped” 16-electron κ 1-diphosphine Ni(0) complex. Moreover, formation of [Ni II(P 2B Cy 4)(Ph)(I)] is inherent to the P 2B Cy 4 secondary coordination sphere: treatment of the Lewis adduct, [Ni 0(P 2B Cy 4) 2(DMAP) 8] with PhI provides [Ni II(P 2B Cy 4) 2(DMAP) 8(I)]I via iodine-atom abstraction and not a [Ni II(Ph)(I)(diphosphine)] compound – an unusual secondary sphere effect. Finally, the reactivity of [Ni 0(P 2B Cy 4) 2] with 4-iodopyridine was surveyed, which resulted in a pyridyl-borane linked oligomer. The implications of these outcomes are discussed in the context of designing strongly donating, and yet labile diphosphine ligands for use in a critical bond activation step relevant to catalysis.

A diaryliodonium salt-based strategy enabled the first systematic synthesis of rarely accessible N-alkoxyindolines. Mechanistic analyses suggested that the reaction likely involves reductive elimination of iodobenzene from iodaoxazepine via a four-membered transition state, followed by Meisenheimer rearrangement. Substrates with N-carbamate protection afforded indole in a manner similar to that of the Ishikawa indole synthesis. Preinstallation of a stannyl group as an iodonium salt precursor greatly expanded the substrate scope, and further mechanistic insights are discussed.

Iodine(III)-mediated synthesis of 4-iodo-N-phenylaniline from iodobenzene has been achieved, and the reaction can proceed under mild conditions. A variety of functional groups were well tolerated, providing the corresponding products in moderate to good yields. The remaining iodine group provides an effective platform for converting the products into several valuable asymmetric diphenylamines. Most importantly, this reaction can be easily scaled up to the ten-gram scale, highlighting its synthetic utility. The mechanistic study revealed that the in situ generated aryl hypervalent iodine intermediate is the key factor to realize this para-selective C-H amination reaction.

5,11-Diazadibenzo[hi,qr]tetracene was synthesized as a new nitrogen-substituted polycyclic heteroaromatic compound by Pd-catalyzed cycloisomerization of an alkyne precursor followed by oxidative cyclization with bis(trifluoroacetoxy)iodobenzene. The substitution of imine-type nitrogen atoms significantly enhanced its electron-accepting character and facilitated the direct nucleophilic addition of arylamines under strongly basic conditions to afford the desired amino-substituted products. The introduction of amino groups induced a remarkable red-shift in their absorption spectra; the tetrasubstituted product exhibited intense near-infrared absorbing property. Furthermore, the π-electronic system, which includes a redox-active 1,4-diazabutadiene moiety, underwent reversible interconversion to its corresponding reduced form upon reduction with NaBH4 and aerobic oxidation.

A series of furan–yne systems were transformed into the corresponding para-benzoquinone derivatives by gold(ΙΙΙ) catalyst. The two-step procedure consisted of a phenol synthesis and subsequent oxidation with iodobenzene diacetate. The reactions can be carried out in a one-pot procedure with the same precatalyst. The para-benzoquinone could simply be converted into the corresponding hydroquinones by reduction with sodium dithionate. This protocol features high efficiency, mild conditions, and wide substrate scopes.

β-Carboline is also known as nor-harmane. It is a nitrogen-containing heterocyclic compound formed in plants and animals as Maillard reaction products between amino acids and reducing sugars or aldehydes. These tricyclic nitrogen heterocyclics play a vital role in medicinal chemistry, due to significant biological activities of their derivatives. It is also a key pharmacophore present in a large number of natural tricyclic alkaloids. Current work is reported with the synthesis and antibacterial activity screening of a new series of N-Substituted-9H-β-carboline-6-amine derivatives. The title compounds were synthesized according to the well known Pictet Spengler reaction in three steps by taking 5-Chlorotryptamine and glyoxalic acid as starting materials. This is an acid-catalyzed intramolecular condensation of an iminium ion and an aromatic C-nucleophile which resulted in the formation of 6-Chloro-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indol-2-ium-1-carboxylate (3). Oxidative decarboxylation and aromatization of compound 3 with iodobenzene diacetate led to the 6-Chloro-β–carboline (4) which were treated with different mono substituted amines gave the title compounds (5 a-J). Structures of the synthesized entities were confirmed spectroscopically (FT-IR, 1H NMR and Mass) and screened for antibacterial activity against various pathogenic bacterial strains ( Streptococcus pyogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) by disc diffusion method. The title compounds showed moderate to good antibacterial activity.

Over the past ten years, a combination of organic additive and t-BuOK/t-BuONa has been successfully used for the direct C–H arylation of arenes. Conceptually different from transition-metal-catalyzed cross-coupling reactions, these t-BuOK-mediated reactions have raised significant curiosity among organic chemists. Herein, a systematic computational study of each elementary step of the t-BuOM (M = K, Na, Li)/N 1,N 2-dimethylethane-1,2-diamine (DMEDA) mediated direct C–H arylation of benzene is detailed. The presented mechanistic proposal relies on the complexation and reaction of t-BuOM with DMEDA (additive), which leads to the formation of different complexes such as SED(M+)…PhI. These complexes mainly involve coordination of the metal ion (from t-BuOM) to the additive and iodobenzene via stabilizing cation–lone pair and cation–π interactions. Such complexation of a metal ion to an additive and iodobenzene not only ensures facile electron transfer to iodobenzene but also provides a lowest energy pathway for the subsequent radical addition and deprotonation step.

N-oxyl radicals of various structure were generated by oxidation of corresponding N hydroxyimides with iodobenzene diacetate, [bis(trifluoroacetoxy)]iodobenzene and ammonium cerium (IV) nitrate in ...

A series of geminal β,β-ditosyloxy ketones were synthesized in moderate to good yields through hydroxy(tosyloxy)iodobenzene-mediated ditosyloxylation of readily accessible α,β-unsaturated ketones in a polar aprotic solvent. A mechanism has been proposed for the synthesis of the geminal β,β-ditosyloxy ketones, and entails an oxidative rearrangement involving a 1,2-aryl migration.

An iodobenzene-catalyzed oxidative cyclization of Michael adducts of activated methylene compounds with nitroolefins or chalcones is developed. mCPBA is used as oxidant together with Bu4NI for the generation of a highly reactive iodine(III) species to mediate the cyclopropanation via a ligand exchange and reductive elimination process. A range of highly functionalized cyclopropanes are synthesized with high diastereoselectivities.

In this study, we demonstrated that the Suzuki–Miyaura catalyst transfer polycondensation (SCTP) of the triolborate-type fluorene monomer, viz. potassium 2-(7-bromo-9,9-dihexyl-9H-fluorene-2-yl)triolborate, can be an efficient and versatile approach to the precise synthesis of poly[2,7-(9,9-dihexylfluorene)]s (PFs) and PF-containing block and graft copolymers. SCTP of the triolborate-type monomer proceeded rapidly in a THF/H2O mixed solvent at −10 °C using an iodobenzene derivative/Pd2(dba)3·CHCl3/t-Bu3P initiating system. Kinetic and post-polymerization experiments revealed that SCTP proceeded via the chain-growth and living polymerization mechanisms. The most important feature of the present polymerization system is that only a small amount of base and water can sufficiently promote the reaction. The well-controlled nature of this polymerization system enabled the synthesis of high-molecular-weight PFs (Mn = 5–69 kg mol−1) with narrow dispersity (ĐM = 1.14–1.38) and α-end-functionalized PFs. Most importantly, PF-containing block and graft copolymers were successfully synthesized, beginning with various iodobenzene-functionalized macroinitiators; this was difficult to achieve by the conventional SCTP of pinacolboronate-type fluorene monomer. One of the key factors for the successful block and graft copolymer syntheses is the reduced water content in the polymerization medium, which suppressed the potential precipitation/aggregation of the macroinitiators.

Irradiation of dichloroethane solutions of different bile acids with diacetoxy(iodobenzene) and iodine followed by treatment of the resulting raw mixture with MCPBA led to the 41–50% yields of the corresponding dehomologated alcohols in an uncomplicated one-pot protocol that can be completed in less than one day of work.

A convenient approach for the synthesis of β-cyanoepoxides is illustrated by iodine(III)-catalyzed epoxidation of electron-deficient β-cyanostyrenes, wherein the active catalytic iodine(III) species was generated in situ. The epoxidation of β-cyanostyrenes was performed using 10 mol% PhI as precatalyst in the presence of 2.0 equivalents Oxone as an oxidant and 2.4 equivalents of TFA as an additive at room temperature under ultrasonic radiations. The β-cyanoepoxides were isolated in good to excellent yields in a short reaction time.

A visible-light-promoted regioselective coupling of C(sp3)-H of aryl-2H-azirine and (diacetoxy)iodobenzene has been reported. Rose Bengal as an organophotoredox catalyst has been used in this react...

A series of acetoxylated 2-arylquinazolines have been successfully synthesized via the Pd-catalyzed and quinazoline-directed C–H activation/acetoxylation of the corresponding 2-arylquinazolines with iodobenzene diacetate in AcOH/Ac2O.

Synthesis of a series of 3,6-disubstituted-bis-1,2,4-triazolo-[4,3-b][3′,4′-f]pyridazines (4) was accomplished by the oxidative intramolecular cyclization of 6-arylidenehydrazino-3-aryl-1,2,4-triazolo[4,3-b]pyridazine (3) using iodobenzene diacetate (IBD), as a green oxidant, in dichloromethane at room temperature. The compounds 3 and 4 were characterized by IR, NMR (1H and13C), mass spectral data and elemental analyses. X-ray crystal analysis of sterically strained 3,6-di-(2′-fluorophenyl)-bis-1,2,4-triazolo-[4,3-b][3′,4′-f]pyridazine 4f and 3,6-di-(4′-fluorophenyl)-bis-1,2,4-triazolo-[4,3-b][3′,4′-f]pyridazine 4g indicated that pyridazine ring has twisted conformation leading to nonplanar tricyclic core. Both compounds crystallized in orthorhombic P212121 space group, containing one single molecule per asymmetric unit. The studies reveal that the compound 4f is associated with weak, centrosymmetric F⋯F interactions (distance of 2.882(3) A), with cis geometry, between adjacent molecules which are responsible for the formation of chains along a axis. Additionally, compounds 4 were screened for their cytotoxic activity against the human cervical carcinoma (HeLa) cell line using MTT assay, however, with not much significant activity.

Nickel-catalyzed regioselective C–H oxygenation reactions of chelating arenes using iodobenzene diacetate, alcohols, and benzoic acids respectively as attacking reagents have been developed for the first time. Simplicity of operation, broad range of functional group tolerance, use of cheap transition metal nickel, and avoiding extraneous directing groups are the key features, thus providing an important complement to C–H oxygenation reactions and expanding the field of nickel-catalyzed C–H functionalizations. Explorations of mechanistic details are also described.

A convenient Co-catalyzed three-component decarbonylative alkylative esterification of styrene derivatives with aliphatic aldehydes and iodobenzene diacetate to provide chain elongated acetates and benzoates has been developed. Readily available aliphatic aldehydes are decarbonylated into 1°, 2° and 3° alkyl radicals for the construction of a C(sp3)–C(sp3) bond via radical addition and an interconversion of CoII–CoIII–CoI complexes is accountable for the formation of a C(sp3)–O bond.

A new synthetic methodology for azaspiro-γ-lactones is reported. The key C–H spirolactonization was accomplished by employing iodobenzene diacetate and potassium bromide to afford a variety of azaspiro-γ-lactones in high yields. The reaction was also applicable to the preparation of a bislactone derivative.

A series of novel magnetic recyclable Pd Au nanoclusters (NCs) catalysts x-PdAur/Fe3O4@LDH (x: Pd loading in wt%, r: Au/Pd molar ratio, LDH: layered double hydroxide, here refers the typical MgAl-LDH) were synthesized by a facile polyol reduction followed sol immobilization of PdAur–PVP on core@shell support Fe3O4@LDH. Systematic characterizations reveal that the obtained catalysts possess the honeycomb-like core@shell, and the ultrafine PdAu alloy nanoclusters with the size in 1.70–2.55 nm highly dispersed on the LDH nanoplates shell. The obtained catalysts 1.0-PdAur/Fe3O4@LDH (r: 0.11, 0.16 and 0.48) show higher Heck activity of iodobenzene with styrene than monomentallic ones, especially 1.0-PdAu0.16/Fe3O4@LDH displays the highest Heck activity under the optimal condition. Moreover, the catalysts can be applied for the Heck reaction of a variety of aryl halides with alkenes, and can be conveniently separated by an external magnet and reused ten runs without significant loss of activity.

Novel, simple and efficient catalytic system based on a polymer supported Pd complex of 2,6-bis(benzimidazolyl)pyridine, Pd(PS BBP)Cl2, was found to be highly active for Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acids under mild conditions. The catalyst was characterized by CHN analyses, thermogravimetric analyses, BET surface area measurements, ICP-OES, FT-IR and electronic spectral studies. The effect of solvent, base, temperature and catalyst concentration on the coupling reaction of iodobenzene with phenylboronic acid was also investigated. A variety of functional groups are tolerated. The novel catalyst could be recovered in a facile manner from the reaction mixture and could be reused up to seven times without significant loss of catalytic activity.

Direct arylation is an appealing method for preparing π-conjugated materials, avoiding the prefunctionalization required for traditional cross-coupling methods. A major effort in organic electronic materials development is improving the environmental and economic impact of production; direct arylation polymerization (DArP) is an effective method to achieve these goals. Room-temperature polymerization would further improve the cost and energy efficiencies required to prepare these materials. Reported herein is new mechanistic work studying the underlying mechanism of room temperature direct arylation between iodobenzene and indole. Results indicate that room-temperature, Pd/Ag-catalyzed direct arylation systems are radical-mediated. This is in contrast to the commonly proposed two-electron mechanisms for direct arylation and appears to extend to other substrates such as benzo[b]thiophene and pentafluorobenzene.

Herewith, we report on a method that allows to simultaneously protect both the ∆14,15 bond and the carbonyl group of the symmetrical bis-steroidal diketone 2. We found that environmentally friendly and gas-free chlorination is ideally suited to achieve this goal. This method was discovered during our efforts to methoxylate 2 in a solution of dichloromethane and basic methanol in the presence of diacetoxy iodobenzene. Unexpectedly, the ∆14,15 bonds were chlorinated once as well as twice in a statistical manner. Interestingly, the singly dichlorinated desymmetrized product is an ideal precursor for conduction a series of position selective transformations. Importantly, the carbonyl group present in the nonchlorinated hemisphere can be selectively reduced, olefinated or oximated, while the other carbonyl group stays unaltered. A structurally related “monomeric” steroid derivative undergoes ∆14,15 chlorination and 11-position methoxylation under same conditions. These findings represent a powerful entry for preparing new nonsymmetrical cephalostatin derivatives., Natural product chemistry; Organic chemistry; Biochemistry; Cancer research, Cephalostatin 1; Chemo and regioselective transformations.; Gas-free chlorination method; Double-functional protection.

A thorough experimental optimization of supported ionic liquid catalyst (SILCA) was performed in order to obtain a stable and efficient catalyst for the Heck reaction. Out of fifteen proposed structures, propyl imidazolium bromide-tetramethylguanidinium pentanoate modified SiO2 loaded with PdCl2 appeared to be the most stable and to have a good activity in the reaction between butylacrylate and iodobezene, resulting in a complete conversion in 40 min at 100 &deg, C, in four consecutive experiments. This study elucidated on the stability of the catalytic system with an ionic liquid layer during the catalyst synthesis but also under reaction conditions. In the bis-layered catalyst, the imidazolium moiety as a part of internal layer, brought rigidity to the structure, while in external layer pentanoic acid gave sufficiently acidic carboxylic group capable to coordinate 1,1,3,3-tetramethylguanidine (TMG) and thus, allow good dispersion of Pd nanoparticles. The catalyst was characterized by means of XPS, FT-IR, TEM, ICP-OES, &zeta, potential, EDX, TGA, and 13C NMR. The release and catch mechanism was observed, whereas Pd re-deposition can be hindered by catalyst poisoning and eventual loss of palladium.

Aminocarbonylation of alkenyl and (hetero)aryl iodides using medium-sized 3-aminolactams as N-nucleophiles was carried out in the presence of in situ palladium(0) catalysts. While the iodoalkenes were converted to the corresponding carboxamide under mild reaction condition (1 bar of CO, 50 °C) by using Pd(OAc)2/PPh3 catalysts, the iodobenzene shown decreased reactivity (39% conversion after 2 days) under the similar reaction conditions in the presence of 3-aminoazepan-2-one. The reactivity of iodobenzene and other iodo(hetero)aromatic substrates was increased with 3-aminoazepan-2-one under high (40 bar) carbon monoxide pressure, but the chemoselectivity was shifted towards the 2-ketocarboxamides formed via double carbon monoxide insertion (except 2-iodopyridine). Changing triphenylphosphine to Xantphos, the expected carboxamides were chemoselectively formed in all cases when iodo(hetero)aryl substrates were used in the presence of all of the three 3-aminolactams under mild reaction conditions. The products synthesized in the reactions mentioned above were isolated in moderate to high yields.

Here we report a metal-free C-N coupling reaction for carbazole synthesis by distal (- meta) C-H bond functionalization. Nitrenium ion, a potential synthetic intermediate, was generated in situ from reactions of iodine(III) reagents and biarylsulfonanilides. Following, nitrenium ions were used for intramolecular dehydrogenative C-N coupling reactions via 1,2-alkyl (methyl or ethyl) migration by the expense of C-H bond functionalization at the distal position toward synthesis of 1,2,4-trialkyl-substituted carbazoles. The iodine(III) condition was either maintained by using a stoichiometric amount of phenyliodine diacetate (PIDA) or in-situ generated from iodobenzene (PhI)- meta-chloroperbenzoic acid ( mCPBA) combination.

Various 2-, 3- and 4-substituted iodobenzenes were aminocarbonylated using aminothiazole and aminothiadiazole derivatives in palladium-catalysed reaction. The reaction is chemospecific toward the corresponding carboxamides. Consequently, the application of the above N-nucleophiles provided the N-1,3-thiazol-2-yl- and N-1,3,4-thiadiazol-2-ylcarboxamides in moderate to high yields. Due to the facile work-up of the reaction mixture isolated yields of 90% or higher were obtained in most cases.

A simple, green protocol has been accomplished for the synthesis of dihydrospirofuro[2,3-c]pyrazoles in aqueous medium involving pyrazolone and aldehydes in a one-pot reaction promoted by bis(acetoxy)iodobenzene (BAIB) at ambient temperature. The protocol presented herein describes a new transformation where two molecules of pyrazolone react with an aldehyde in a Knoevenagel condensation followed by a Michael addition, and the resulting dienol was rearranged to the title compound. High compatibility, easy work-up, and excellent yields are the advantages of this protocol.

N-substituted oxindoles were obtained through a facile KOH/DMSO promoted intramolecular cyclization of o-bromophenylacetamides in good yields. Furthermore, isoindigo derivatives were readily synthesized through sequential intramolecular cyclization, oxidation and condensation of o-bromophenylacetamide in the presence of copper (II) acetate monohydrate, iodobenzene diacetate and KOH/DMSO. This method provides a convenient synthesis of a range of oxindoles and symmetrical biologically important (E)-bisindole-2-ones using o-bromophenylacetamide as sole starting material. The reaction mechanism is elucidated in light of the control experiment results.

Herein we examine the end-capping efficacy of several end-capping reagents (ECRs) in the Stille polymerization of 2,7-dibromo-9,9-bis(2-ethylhexyl)fluorene (Fl) and 2,5-bis(trimethylstannyl)-thieno[3,2-b]thiophene (TT). Polymerizations were carried out in a one-pot fashion where the molar ratio of TT relative to Fl was biased, ideally generating bis(trimethylstannyl) macromolecules. Various ECRs (bromobenzene, 4-bromotoluene, 4-(trifluoromethyl) bromobenzene, 4,4′-bromobiphenyl, 2-bromo-9,9-dimethylfluorene, iodobenzene, 4-iodotoluene, and 4,4′-iodobiphenyl) differing in reactivity were employed in the one-pot reaction. Polymers were characterized using GPC, 1H NMR, and end-capping efficacy was evaluated with MALDI-ToF MS. The iodo derivatives were found to disrupt propagation, severely inhibiting molecular weight. The bromo ECRs varied in end-capping efficiency: bromofluorene ∼ bromobiphenyl > trifluoromethylbromobenzene ∼ bromobenzene > bromotoluene. Additionally, we demonstrate a strong efficiency dependence on initial monomer concentration and demonstrate this method's superiority over post-polymerization end-capping.

Although there has been a lot of progress in oxidative arene C–H functionalization reactions catalyzed by Pd(II/IV) system, the non-directed, site-selective functionalization of arene molecules is still challenging. It has been established that ligands play a pivotal role in controlling rate- as well as selectivity-determining step in a catalytic cycle involving well-defined metal-ligand bonding. N-heterocyclic carbene (NHC) ligands have had a tremendous contribution in the recent extraordinary success of achieving high reactivity and excellent selectivity in many catalytic processes including cross-coupling and olefin-metathesis reactions. However, the immense potential of these NHC ligands in improving site-selectivity of non-directed catalytic C–H functionalization reactions of simple arenes is yet to be realized, where overriding the electronic bias on deciding selectivity is a burdensome task. The presented work demonstrated an initiative step in this regard. Herein, a series of well-defined discrete [Pd( NHC R ′ R )(py)I2] complexes with systematically varied degree of spatial congestion at the Pd centre, exerted through the R and R’ substituents on the NHC ligand, were explored in controlling the activity as well as the site-selectivity of non-directed acetoxylation of representative monosubstituted and disubstituted simple arenes (such as toluene, iodobenzene and bromobenzene, naphthalene and 1,2-dichlorobenzene). The resulting best yields were found to be 75% for toluene and 65% for bromobenzene with [Pd( NHC Me Ph )(py)I2], 75% for iodobenzene and 79% for naphthalene with [Pd( NHC Me Me )(py)I2], and 41% for 1,2-dichlorobenzene with [Pd( NHC Cy Cy )(py)I2]. Most importantly, with increasing the bulkiness of the NHC ligand in the complexes, the selectivity of the distal C-acetoxylated products in comparison to the proximal ones, was enhanced to a great extent in all cases. Considering the vast library of NHC ligands, this study underscores the future opportunity to develop more strategies to improve the activity and the crucial site-selectivity of C–H functionalization reactions in simple as well as complex organic molecules.

Pseudo‐Grignard reagents PhLnI (Ln=Yb, Eu), readily prepared by the oxidative addition of iodobenzene to ytterbium or europium metal at −78 °C in tetrahydrofuran (THF) or 1,2‐dimethoxyethane (DME), react with a range of bulky N,N′‐bis(aryl)formamidines to generate an extensive series of LnII or more rarely LnIII complexes, namely [Eu(DippForm)I(thf)4]⋅thf (1), [{EuI2(dme)2}2] (2), [Eu(XylForm)I(dme)2]⋅0.5 dme (3 a), [Eu(XylForm)I(dme)(μ‐dme)]n (3 b), [{Eu(XylForm)I(μ‐OH)(thf)2}2] (4), [Yb(DippForm)I(thf)3]⋅thf (5 a), [Yb(DippForm)I2(thf)3]⋅2 thf (5 b), [{Yb(MesForm)I(thf)2}2] (6), [{Yb(XylForm)I(thf)2}2] (7 a), and [Yb(XylForm)2I(dme)]⋅dme (7 b) {(Form=ArNCHNAr; XylForm (Ar=2,6‐Me2C6H3), MesForm (Ar=2,4,6‐Me3C6H2), DippForm (Ar=2,6‐iPr2C6H3)}. Reaction of PhEuI and MesFormH in DME consistently gave 2, and reaction with XylFormH in THF gave 4. Europium complexes 1 and 3 a are seven‐coordinate divalent monomers, whilst 3 b is a seven‐coordinate dme‐bridged polymer. Complex 5 a of the smaller YbII is a six‐coordinate monomer, but the related 6 and 7 a are six‐coordinate iodide‐bridged dimers. 4 is a trivalent seven‐coordinate hydroxide‐bridged dimer, whereas complexes 5 b and 7 b are seven‐coordinate monomeric YbIII derivatives. A characteristic structural feature is that iodide ligands are cisoid to the formamidinate ligand. To illustrate the synthetic scope of the pseudo‐Grignard reagents, [Yb(Ph2pz)I(thf)4] (Ph2pz=3,5‐diphenylpyrazolate) was oxidised with 1,2‐diiodoethane to afford seven‐coordinate monomeric pyrazolato‐ytterbium(III) iodide [Yb(Ph2Pz)I2(thf)3] (8) in high yield, whilst metathesis between [Yb(Ph2pz)I(thf)4] and NaCp (Cp=C5H5) gave [Yb(C5H5)(Ph2pz)(thf)]n (9), a nine‐coordinate η5:η5‐Cp‐bridged coordination polymer. Reaction of the pseudo‐Grignard reagent MeYbI with KN(SiMe3)2 gave [K(dme)4][Yb{N(SiMe3)2}3] (10) with a charge‐separated three‐coordinate homoleptic [Yb{N(SiMe3)2}3]− anion, a complex that could be obtained in high yield by deliberate synthesis from YbI2 and KN(SiMe3)2 in DME.

Copper(I)-catalyzed arylation of 14 adamantane-containing amines with iodobenzene, 1-fluoro-4-iodobenzene, 1-iodo-4-(trifluoromethyl)benzene, and 1-iodo-4-methoxybenzene has been studied under the conditions optimized previously. The yields of the N-arylation products have been shown to depend in a complicated manner on the amine structure, steric environment of the amino group, and substituent nature in iodobenzene.

Five tetradentate ligands, L1–5, bearing the moiety of bis(pyridin-2-ylmethyl)amine (1) and their complexes with Mn(II) were prepared. All the compounds and metal complexes were appropriately characterized. The five manganese(II) complexes (3a–e) are of the formula, [Mn(II)LxCl2] (x = 1-5), as suggested by the crystal structure of complexes 3b and 3c. All the ligands except for L3 possess two iodobenzene groups via an ether linkage (except for L1) with various lengths. By using oxone as an oxidant, the catalytic activity of these complexes on the oxidation of ethylbenzene to acetophenone in acetonitrile/water at room temperature was studied. Our results showed that the pendant iodophenyl groups play a synergetic role with the metal center in the catalysis, and complex 3b possesses the most appropriate length of the linkage between the iodobenzene group and the metal center. EPR and FTIR data suggest that the metal center of the active species should be Mn(IV) after the oxidation of oxone under the reaction conditions. A catalytic mechanism was also proposed based on the experimental observations.

A series of poly(arylene ether ketone)s (PAEKs) with dense sulfonic-acid-functionalized pendants were successfully synthesized by the Ullmann C–N coupling of a polymer precursor containing pendant iodobenzene rings and 3,6-ditrityl-9H-carbazole, followed by sulfonation using chlorosulfonic acid. A tough transparent membrane, which exhibited suitable dimensional stability and high proton conductivity, was obtained by casting an N,N-dimethylacetamide polymer solution. DSPAEK-CZ-25 (IEC = 2.03 meq. g−1, where IEC = ion-exchange capacity) exhibited the highest proton conductivity of 177 mS cm−1 at 100 °C; this value is significantly greater than that of Nafion 117. In terms of molecular design, the large difference in polarity between the fluorinated polymer backbone and the concentrated pendant sulfonic acid groups possibly induces good phase-separation morphology, which enhances conductivity and dimensional stability. The obtained membranes exhibited excellent thermal stabilities and good mechanical properties. Overall, the DSPAEK-CZ polymers exhibited outstanding comprehensive performance as potential materials for proton exchange membranes (PEMs).

The coupling of dimethyl phosphite and iodobenzene occurs in the presence of catalytic amounts of homoligand carbonyl complexes of chromium subgroup metals to form dimethyl phenylphosphonate in yields of 50–73% depending on the metal.

1-Butyl-3-methyltetrazolium-5-olate (1), a mesoionic compound, exists as a liquid at room temperature and can be used as a polar solvent for the Mizoroki-Heck reaction, wherein it has been proven to be a superior solvent to other solvents. The reaction of iodobenzene with ethyl acrylate in the presence of palladium acetate in mesoionic liquid 1 at 40 °C for 24 h gave ethyl cinnamate in 78% yield in the absence of ligands, while the use of other solvents, such as [bmim][BF4], [bmim][PF6], and DMF gave lower yields (43%, 37%, and 17%, respectively) under the same conditions. Heck-type coupling reactions of electron-deficient or electron-rich aryl iodides and bromobenzenes with olefins (15 examples, 7%–97%) were performed in 1. When a phosphine ligand was added to the reaction mixture, aryl bromides could be used, and the mesoionic liquid containing the catalysts could be reused at least five times.

A Nickel catalyzed C-S formation protocol for the synthesis of diarylsulfides was developed. Catalyzed by NiCl2, phenyldithiocarbamates reacted with iodobenzenes furnishing diarylsulfides smoothly with good to excellent yields (66-93%). The protocol has the features of cheap catalyst, easy performance, broad substrate scope and nice yields, affording an alternative way for the preparation of diarylsulfides.

Arylation of adamantane-containing amines with iodobenzene in the presence of copper(I) and copper(II) compounds and various N,N-, N,O- and O,O-bidentate ligands was studied. The best results were obtained using the catalytic system CuI–rac-BINOL [1,1′-bi(naphthalen-2-ol)] (10/20 mol %). Reactions with iodobenzene derivatives containing electron-donor and electron-withdrawing substituents in the para position to the iodine atom were carried out under the optimal conditions.

Employing an optimized Pd-catalyzed cross-coupling reaction promoted by CuI, novel N -ferrocenylpyridazinones along with N -phenyl- and N -(2-pyridyl) analogues were synthesized from readily available heterocyclic precursors, iodoferrocene, iodobenzene and 2-bromopyridine. With exception of the ferrocenylation of 6-ferrocenylpyridazin-3(2 H )-one yielding both N - and O-substituted products, the studied reactions exclusively afforded N -aryl lactams. The novel compounds exhibited cytotoxicity towards HEPG2 and HT-29 human malignant cells under in vitro conditions. The measured IC 50 values supplemented with the results of cyclic voltammetry and DFT calculations suggest that the cytotoxic activity of the N - and O -ferrocenyl-substituted derivatives and the decreased effect of the N -phenyl analogues seem to be at least partly associated with the potential to generate reactive oxygen species (ROS). This interpretation, allowing the prediction of characteristic substituent-dependent SAR, was supported by the results of related studies on the practically inactive N -(2-pyridyl)pyridazinones assumed to be present in protonated chelate forms with highly a decreased propensity to undergo ionization.

Iron-catalyzed direct arylations of unactivated arenes with aryl iodides provide an important method to form C-C bonds. The present study explored the mechanisms of iron(II)-catalyzed direct arylation of Iodobenzene with Benzene using Density Functional Theory (DFT) calculations at the B3LYP-D3 level, which included the halogen atom transfer (to produce aryl radical) mechanism, the single electron transfer mechanism, the σ–bond metathesis mechanism and the oxidative addition mechanism. The calculated results showed that the halogen atom transfer mechanism was favored. The rate-limiting step for the halogen atom transfer mechanism was the first step to produce the phenyl radical with the energy barrier of ΔE = 29.8 kcal/mol in the gas phase and the Gibbs free energy in solvent benzene ΔG sol = 37.7 kcal/mol. The substituent effects of phenyl iodide were also studied.

A novel ionic liquid based on a highly fluorinated phosphonium cation was synthesized and its physicochemical properties were compared to its semi- and non-fluorinated analogue. The fluorinated ionic liquid was found to show a thermomorphic mixing behavior with organic solvents so that it could be applied as a substitute for volatile perfluorinated solvents in fluorous biphasic catalysis to achieve the recovery of perfluoro-tagged catalysts. Efficient immobilization of a perfluoro-tagged palladium catalyst in the fluorous ionic liquid phase was demonstrated for the Heck reaction as a model reaction of the widely applied Pd-catalysed C C coupling reactions. The reaction of iodobenzene and methyl acrylate resulted in 83% yield after 20 runs proofing the efficient immobilization in the fluorophilic ionic liquid.

(Diacetoxyiodo)benzene or iodine(III) catalyst, in situ generated from iodobenzene precatalyst with Oxone, promotes the cycloisomerization–amination sequence of N-propargyl carboxamides with bis(sulfonyl)imides under mild conditions, thereby leading to the direct formation of oxazoles bearing nitrogen functional groups.

The first catalytic oxygenative allylic transposition of unactivated alkenes into enones has been developed using an oxoammonium salt as a catalyst. This reaction converts various tri- and trans-disubstituted alkenes into their corresponding enones with transposition of their double bonds at ambient temperature in good yields. The use of a less-hindered azaadamantane-type oxoammonium salt as the catalyst and a combination of two distinct stoichiometric oxidants, namely, iodobenzene diacetate and magnesium monoperoxyphthalate hexahydrate (MMPP·6H2O) are essential to facilitate the enone formation efficiently.