Reaction of [η¹:η⁵‑(R₂NCH₂CH₂)C₂B₉H₁₀]TaMe₃ with Isonitriles: Effects of Nitrogen Substituents on Product Formation

Tantallacarborane trimethyl complexes show diverse reactivity patterns toward isonitriles. Reaction of [η¹:η⁵-(Me₂NCH₂CH₂)­C₂B₉H₁₀]­TaMe₃ (<b>1</b>) with 1-adamantyl isonitrile (AdNC) led to the clean formation of an imido complex, [σ:η⁵-(MeNCH₂CH₂)­C₂B₉H₁₀]­Ta­(NAd)­(THF) (<b>2</b>) with elimination of methane and 2-methylpropene, whereas treatment of [η¹:η⁵-{(CH₂)₅NCH₂CH₂}­C₂B₉H₁₀]­TaMe₃ (<b>3</b>) with AdNC under the same reaction conditions gave the cage B–H activated product {σ:η¹:η⁵-[(CH₂)₅NCHCH₂]­(CHMe₂)­C₂B₉H₉}­Ta­(NAd)­(THF) (<b>4</b>). An equimolar reaction of <b>1</b> with R¹NC (R¹ = Cy, Ad), followed by 1 equiv of R²NC (R² = Xyl, Cy), afforded the imido amido complexes [η¹:η⁵-(Me₂NCH₂CH₂)­C₂B₉H₁₀]­Ta­(NR¹)­[N­(CMeCMe₂)­R²] (R¹ = Ad, R² = Cy (<b>5</b>); R¹ = Cy, R² = Xyl (<b>6</b>)). If 2 equiv of 2,6-dimethylphenyl isonitrile (XylNC) was used in the above reaction, the cage B–H alkylation products [η¹:η⁵-(Me₂NCH₂CH₂)­C₂B₉H₉]­Ta­(NR¹)­[N­(Xyl)­{CHC­(Me₂)­C­(Me)NXyl}] (R¹ = Cy (<b>7</b>), Ad (<b>8</b>)) were isolated. On the other hand, η²-iminoacyl imido complexes [η¹:η⁵-(Me₂NCH₂CH₂)­(CHMe₂)­C₂B₉H₉]­Ta­(NXyl)­(η²-<i>C</i>,<i>N</i>-MeCNR) (R = ^<i>i</i>Pr (<b>9</b>), Cy (<b>10</b>)) were obtained from an equimolar reaction of <b>1</b> with XylNC, followed by 1 equiv of alkyl isonitriles. A double methyl migratory insertion tantallaaziridine species is proposed as a crucial intermediate for all aforementioned reactions, and follow-up steps are dependent upon N-substituents and the type and stoichiometry of isonitriles. All new complexes were characterized by spectroscopic methods and single-crystal X-ray analyses

Tantallacarborane Mediated Consecutive C–C and C–N Coupling Reactions of Alkyl Isonitriles: A Facile Route to N‑Heterocycles

Reactions of tantallacarborane methyl complexes ([η¹:η⁵-(Me₂NCH₂CH₂)­C₂B₉H₁₀]­TaMe₃ (<b>1</b>) and [η¹:η⁵-(MeOCH₂CH₂)­C₂B₉H₁₀]­TaMe₃ (<b>8</b>)) with alkyl isonitriles have been studied. Complex <b>1</b> reacted with 1 equiv of RNC (R = TMSCH₂, Cy, and ^<i>i</i>Pr) to afford double migratory insertion products [η¹:η⁵-(Me₂NCH₂CH₂)­C₂B₉H₁₀]­Ta­[η²-<i>C</i>,<i>N</i>-C­(Me₂)­NCH₂TMS]­Me (<b>2</b>) and [σ:η¹:η⁵-{MeN­(CH₂)­CH₂CH₂}­C₂B₉H₁₀]­Ta­[N­(^<i>i</i>Pr)­R]­Me (R = Cy (<b>3</b>), ^<i>i</i>Pr (<b>4</b>)). However, treatment of <b>1</b> or <b>8</b> with 4 equiv of alkyl isonitriles gave two fused six-membered <i>N</i>-heterocycles <b>5</b>–<b>7</b> and <b>9</b> via consecutive C–C/C-N bond-forming reactions. All new complexes were characterized by ¹H, ¹³C, and ¹¹B NMR spectra as well as elemental analyses. Their structures were further confirmed by single-crystal X-ray analyses. The results show that aryl and alkyl isonitriles exhibit significantly different reactivity patterns. This work also offers a very efficient method for the synthesis of N-heterocycles

Dinuclear Iron–Imido Complexes with <i>N</i>-Heterocyclic Carbene Ligation: Synthesis, Structure, and Redox Reactivity

The introduction of an <i>N</i>-heterocyclic carbene ligand (NHC) to iron–imido chemistry has led to the successful preparation of a series of iron–imido complexes featuring rhombic [Fe­(μ₂-NDipp)₂Fe]^<i>n</i> (<i>n</i> = 0, 1+, 2+) cores. The dimeric iron­(II)–imido complex [(IPr₂Me₂)­Fe­(μ₂-NDipp)₂Fe­(IPr₂Me₂)] (<b>1</b>) was prepared by protonolysis of the ferrous precursor [(IPr₂Me₂)­Fe­(Mes)₂] with the aniline derivative DippNH₂. Complex <b>1</b> has a rhombic [Fe­(μ₂-NDipp)₂Fe] core in which the iron sites adopt trigonal-planar geometry and have a formal Fe­(II) oxidation state. Oxidation of <b>1</b> with 1 or 2 equiv of [Cp₂Fe]­[BF₄] resulted in the formation of the dinuclear iron­(III) complex [F­(IPr₂Me₂)­Fe­(μ₂-NDipp)₂Fe­(IPr₂Me₂)­F] (<b>2</b>) or [F­(IPr₂Me₂)­Fe­(μ₂-NDipp)₂Fe­(IPr₂Me₂)­(BF₄)] (<b>3</b>), respectively. However, the reaction of <b>1</b> with benzyl chloride could give either the diferric complex [Cl­(IPr₂Me₂)­Fe­(μ₂-NDipp)₂Fe­(IPr₂Me₂)­Cl] (<b>4</b>) or the mixed-valent complex [(IPr₂Me₂)­Fe­(μ₂-NDipp)₂Fe­(IPr₂Me₂)­Cl] (<b>5</b>), depending on the reaction stoichiometry. Complex <b>5</b> is also accessible upon the reaction of <b>1</b> with <b>4</b>. Complexes <b>1</b>–<b>5</b> have been fully characterized by ¹H NMR, UV–vis spectroscopy, single-crystal X-ray diffraction studies, and elemental analysis. The successful preparation of these complexes revealed the potential of the iron–imido rhomb for mediating electron transfer

Synthesis and Structure of Silicon-Bridged Boratabenzene Fluorenyl Rare-Earth Metal Complexes

A silicon-bridged boratabenzene fluorenyl ligand [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]^2– (<b>L</b>^2–) was designed and synthesized. By employment of this ligand, two divalent rare-earth metal complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(THF)₂ (Ln = Sm (<b>1</b>), Yb (<b>2</b>)) were obtained from salt metathesis of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₂­(THF)₂ in THF. Complex <b>2</b> undergoes redox reaction with cyclooctatetraene to give a trivalent Yb complex [(C₈H₈)­Yb]₂­[μ-{Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)}₂] (<b>3</b>), accompanied with oxidative coupling of two fluorenyl groups. A series of chloro-bridged trimeric trivalent rare-earth metal complexes [Li­(THF)₄]₂­[{[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(μ-Cl)­Li­(THF)₃}₃­(μ-Cl)₃­(μ₃-Cl)₂] (Ln = Nd (<b>4</b>), Sm (<b>5</b>), and Gd (<b>6</b>)) were synthesized by reactions of Li₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>Li</b>_<b>2</b><b>L</b>) with LnCl₃ in THF. Treatment of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₃(THF)_<i>n</i> gave the monomeric complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­LnI­(THF) (Ln = La (<b>7</b>), Nd (<b>8</b>), Sm (<b>9</b>), and Gd (<b>10</b>)). These iodides were subsequently reacted with K­[CH₂C₆H₄-<i>o</i>-NMe₂] to afford THF coordinated benzyl complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(CH₂C₆H₄-<i>o</i>-NMe₂)­(THF) (Ln = La (<b>11</b>), Nd (<b>12</b>), and Gd (<b>13a</b>)) and non-THF coordinated complex [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Gd­(CH₂C₆H₄-<i>o</i>-NMe₂) (<b>13b</b>)

Synthesis and Structure of Silicon-Bridged Boratabenzene Fluorenyl Rare-Earth Metal Complexes

A silicon-bridged boratabenzene fluorenyl ligand [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]^2– (<b>L</b>^2–) was designed and synthesized. By employment of this ligand, two divalent rare-earth metal complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(THF)₂ (Ln = Sm (<b>1</b>), Yb (<b>2</b>)) were obtained from salt metathesis of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₂­(THF)₂ in THF. Complex <b>2</b> undergoes redox reaction with cyclooctatetraene to give a trivalent Yb complex [(C₈H₈)­Yb]₂­[μ-{Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)}₂] (<b>3</b>), accompanied with oxidative coupling of two fluorenyl groups. A series of chloro-bridged trimeric trivalent rare-earth metal complexes [Li­(THF)₄]₂­[{[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(μ-Cl)­Li­(THF)₃}₃­(μ-Cl)₃­(μ₃-Cl)₂] (Ln = Nd (<b>4</b>), Sm (<b>5</b>), and Gd (<b>6</b>)) were synthesized by reactions of Li₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>Li</b>_<b>2</b><b>L</b>) with LnCl₃ in THF. Treatment of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₃(THF)_<i>n</i> gave the monomeric complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­LnI­(THF) (Ln = La (<b>7</b>), Nd (<b>8</b>), Sm (<b>9</b>), and Gd (<b>10</b>)). These iodides were subsequently reacted with K­[CH₂C₆H₄-<i>o</i>-NMe₂] to afford THF coordinated benzyl complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(CH₂C₆H₄-<i>o</i>-NMe₂)­(THF) (Ln = La (<b>11</b>), Nd (<b>12</b>), and Gd (<b>13a</b>)) and non-THF coordinated complex [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Gd­(CH₂C₆H₄-<i>o</i>-NMe₂) (<b>13b</b>)

Reactivity of a Bis(amidinato)iron(II) Complex [Fe(MesC(NPr^<i>i</i>)₂)₂] toward Some Oxidizing Reagents

A diversified reactivity of the mononuclear bis­(amidinato)­iron­(II) complex [Fe­(MesC­(NPr^<i>i</i>)₂)₂] (<b>1</b>) toward oxidizing reagents has been disclosed. The bis­(amidinato)­iron­(II) complex was synthesized from the reaction of [Fe­(Mes)₂]₂ with 4 equiv of diisopropyl carbodiimide in good yield. Treatment of <b>1</b> with 1 equiv of benzyl chloride gives the high-spin ferric complex [FeCl­(MesC­(NPr^<i>i</i>)₂)₂] (<b>2</b>), with 0.25 equiv of S₈ affords the sulfur-insertion product [Fe­(MesC­(NPr^<i>i</i>)­(NPr^<i>i</i>S))₂] (<b>3</b>), with 1 equiv of 3,5-dimethylphenyl azide or phenyl azide yields nitrene-insertion product [Fe­(MesC­(NPr^<i>i</i>)₂)­(Pr^<i>i</i>NC­(Mes)­N­(Pr^<i>i</i>)­NAr)] (Ar = 3,5-dimethylphenyl, <b>4a</b>; phenyl, <b>4b</b>), and with 1 equiv of oxo-transfer reagent, trimethylamine oxide or 2,6-dichloropyridine oxide, generates the oxo-bridged diferric complex [(MesC­(NPr^<i>i</i>)₂)₂FeOFe­(MesC­(NPr^<i>i</i>)₂)₂] (<b>5</b>). Complexes <b>1</b>–<b>3</b>, <b>4a</b>, and <b>5</b> have been characterized by ¹H NMR, UV–vis, IR, elemental analysis, and single-crystal X-ray diffraction studies. The formations of these unusual sulfur- and nitrene-insertion products <b>3</b>, <b>4a</b>, and <b>4b</b>, can be explained by the sequential redox reaction between <b>1</b> and the oxidants, followed by migratory insertion steps

DataSheet1_Comprehensive bioinformatics analysis to identify a novel cuproptosis-related prognostic signature and its ceRNA regulatory axis and candidate traditional Chinese medicine active ingredients in lung adenocarcinoma.docx

Lung adenocarcinoma (LUAD) is the most ordinary histological subtype of lung cancer, and regulatory cell death is an attractive target for cancer therapy. Recent reports suggested that cuproptosis is a novel copper-dependent modulated form of cell death dependent on mitochondrial respiration. However, the role of cuproptosis-related genes (CRGs) in the LUAD process is unclear. In the current study, we found that DLD, LIAS, PDHB, DLAT and LIPA1 in 10 differentially expressed CRGs were central genes. GO and KEGG enrichment results showed that these 10 CRGs were mainly enriched in acetyl-CoA biosynthetic process, mitochondrial matrix, citrate cycle (TCA cycle) and pyruvate metabolism. Furthermore, we constructed a prognostic gene signature model based on the six prognostic CRGs, which demonstrated good predictive potential. Excitedly, we found that these six prognostic CRGs were significantly associated with most immune cell types, with DLD being the most significant (19 types). Significant correlations were noted between some prognostic CRGs and tumor mutation burden and microsatellite instability. Clinical correlation analysis showed that DLD was related to the pathological stage, T stage, and M stage of patients with LUAD. Lastly, we constructed the lncRNA UCA1/miR-1-3p/DLD axis that may play a key role in the progression of LUAD and screened nine active components of traditional Chinese medicine (TCM) that may regulate DLD. Further, in vitro cell experiments and molecular docking were used to verify this. In conclusion, we analyzed the potential value of CRGs in the progression of LUAD, constructed the potential regulatory axis of ceRNA, and obtained the targeted regulatory TCM active ingredients through comprehensive bioinformatics combined with experimental validation strategies. This work not only provides new insights into the treatment of LUAD but also includes a basis for the development of new immunotherapy drugs that target cuproptosis.</p

Reactivity of Scandium Terminal Imido Complex toward Boranes: C(sp³)–H Bond Borylation and B–O Bond Cleavage

Scandium terminal imido complex [(NNNN)­ScNDIPP] (<b>2</b>; NNNN = [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMeCH₂CH₂NMe₂)]⁻, DIPP = 2,6-^<i>i</i>Pr₂C₆H₃) reacts with 9-borabicyclononane (9-BBN) to give scandium borohydride [(NNNN­(B)­H)­Sc­(N­(H)­DIPP)] (<b>3</b>; NNNN­(B)H = [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMeCH₂CH₂N­(Me)­CH₂(BBN)]^2–), and C­(sp³)–H bond borylation of the NNNN ligand occurs during this reaction. In contrast, the reaction between complex <b>2</b> and catecholborane (CatBH) gives scandium catecholate [(NNNN)­Sc­(Cat)] (<b>4</b>), and B–O bond cleavage happens during this reaction. Both <b>3</b> and <b>4</b> have been well-characterized including the single-crystal X-ray diffraction analysis. Reaction of <b>2</b> with bis­(catecholato)­diboron (CatB–BCat) also gives a B–O bond cleavage product

Nonchelated Phosphoniomethylidene Complexes of Scandium and Lutetium

The first phosphoniomethylidene complexes of scandium and lutetium, [<b>L</b>Ln­(CHPPh₃)­X] (<b>L</b> = [MeC­(NDIPP)­CHC­(NDIPP)­Me]⁻; Ln = Sc, X = Me, I, TfO; Ln = Lu, X = CH₂SiMe₃), have been synthesized and fully characterized. DFT calculations clearly demonstrate the presence of an allylic Ln, C, P π-type interaction in these complexes. X-ray diffraction indicates that the scandium iodide complex has the shortest Sc–C bond length to date (2.044(5) Å). These phosphoniomethylidene complexes readily convert into the ylide complexes, and the reactivity is affected by both X^– anion and Ln³⁺ ion. The reaction of lutetium complex with imine shows a rapid insertion of imine into the Lu–C­(alkylidene) bond. DFT calculations indicate that, although the bonding situation seems similar to that of the scandium analog, the strong negative charge at the alkylidene carbon is not sufficiently screened by one hydrogen in the lutetium complex because of a more ionic bonding, and therefore, the reactivity of the lutetium complex is much higher

How to Plant Apple Trees to Reduce Replant Disease in Apple Orchard: A Study on the Phenolic Acid of the Replanted Apple Orchard

<div><p>Apple replant disease (ARD) is an important problem in the production of apple. The phenolic acid is one of the causes of ARD. How phenolic acid affects the ARD was not well known. In this study, we analyzed the type, concentration and annual dynamic variation of phenolic acid in soil from three replanted apple orchards using an accelerated solvent extraction system with high performance liquid chromatography (ASE-HPLC). We found that the type and concentration of phenolic acid were significantly differed among different seasons, different sampling positions and different soil layers. Major types of phenolic acid in three replanted apple orchards were phlorizin, benzoic acid and vanillic aldehyde. The concentration of phenolic acid was highest in the soil of the previous tree holes and it was increased from the spring to autumn. Moreover, phenolic acid was primarily distributed in 30–60 cm soil layer in the autumn, while it was most abundant in 0–30 cm soil layer in the spring. Our results suggest that phlorizin, benzoic acid and vanillic aldehyde may be the key phenolic acid that brought about ARD in the replanted apple orchard.</p></div