It is shown that pnictogenium ions [R2E]+ (E = P, As, Sb, Bi) either insert into the E′E″ bond or coordinate to the phosphorus lone-pair of the tetrahedral heterodipnictogen complexes [{CpMo(CO)2}2(μ,η2:2-E′E″)] (E ≠ E″ = P, As, Sb). Reactivity studies of the obtained three-membered interpnictogen chains with another tetrahedrane unit allowed for the isolation of novel five-membered interpnictogen chain compounds.

The synthesis and characterization of novel three- and five-membered interpnictogen chain compounds are presented. In a systematic study, the heterodipnictogen complexes [{CpMo(CO)2}2(μ,η2:2-EE′)] (Mo 2 PAs: E = P, E′ = As; Mo 2 PSb: E = P, E′ = Sb; Mo 2 AsSb: E = As, E′ = Sb) are reacted with in situ generated pnictogenium ions of a third pnictogen. Phosphenium ions insert into the AsSb bond of Mo 2 AsSb to give [{CpMo(CO)2}2(μ,η1:1:1:1-AsPPh2Sb)][TEF] (1) ([TEF]− = [Al{OC(CF3)3}4]−). In contrast, arsenium, stibenium, and bismuthenium ions, respectively, coordinate to the phosphorus atom of Mo 2 PAs and Mo 2 PSb. The obtained complexes [{CpMo(CO)2}2(μ,η2:2-SbPAsCy2)][BArF24] (2), [{CpMo(CO)2}2(μ,η2:2-AsPSbPh2)][BArF24] (3), and [{CpMo(CO)2}2(μ,η2:2-EPBiPh2)][BArF24] (E = As (5), E = Sb (6)) all contain three different pnictogen atoms in a chain. To even elongate these chains, the stibenium substituted tetrahedranes 3 and [{CpMo(CO)2}2(μ,η2:2-SbPSbPh2)][BArF24] (4) are reacted with an additional equivalent of Mo 2 PAs or Mo 2 PSb yielding novel five-membered chains of the type E-P-SbPh2-P-E′ (E = E′ = As (7); E = E′ = Sb (8); E = As, E = Sb (9)), with alternating pnictogen sequences. 7–9 are found to be only stable in the solid state whereas a rapid equilibration with their respective starting materials 3 or 4 and Mo 2 PAs or Mo 2 PSb is observed in solution.

The peroxo-di-cerium(IV)-di-lithium-containing 32-tungsto-4-phosphate [(CeIV 2O2)Li2(P2W16O59)2]16− (Ce 2 Li 2 P 4 W 32 ) is synthesized and structurally characterized. This peroxo-polyanion demonstrates remarkable stability in solution across a broad pH range. Additionally, the central Ce-peroxo group exhibits exceptional thermal stability, making it one of the most thermally stable peroxo-species reported to date. Furthermore, the oxidative reactivity mechanism of the peroxo-cerium Ce2(O2) unit in Ce 2 Li 2 P 4 W 32 is investigated.

The peroxo-bridged di-cerium(IV)-di-lithium-containing polyoxometalate [(CeIV 2O2)Li2(P2W16O59)2]16− (Ce 2 Li 2 P 4 W 32 ) is synthesized in a one-pot aqueous synthetic procedure and isolated as a hydrated mixed alkali salt, K13.6Na1.4Li[(CeIV 2O2)Li2(P2W16O59)2]·32H2O (KNaLi-Ce 2 Li 2 P 4 W 32 ). The novel polyanion Ce 2 Li 2 P 4 W 32 comprises a side-on peroxo-group bridging two cerium(IV) and two lithium ions, which are encapsulated between two dilacunary, face-on {P2W16} Wells–Dawson units, with a vacant site in each of the two belts. The polyanion Ce 2 Li 2 P 4 W 32 is characterized in the solid state by single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy and in solution by 31P NMR and Raman spectroscopy, respectively. Ce 2 Li 2 P 4 W 32 and the peroxo-group are shown to be highly stable in a large pH range and up to almost boiling temperatures, but at the same time the polyanion is reactive toward oxidation of triphenylphosphine, involving the peroxo group and the cerium(IV) centers.

Herein, direct deoxygenative borylation of acyl chlorides is reported, which is an unknown but desirable chemical transformation. The N-heterocyclic nitrenium ion has been utilized as the photocatalyst under mild reaction conditions to synthesize a series of alkylboronates using bis-(catecholato)diboron (B2cat2) as the diboron reagent. The reaction follows a radical pathway, with breaking of the CO bond as the key step.

Considering the appealing synthetic properties of oxygenous feedstocks and organoboron compounds, direct deoxygenative borylation is a very desirable chemical transformation. Directly converting acyl chlorides into alkylboronates through deoxygenative borylation is an unknown but valuable reaction. Herein, a relatively straightforward one-step methodology is reported where the N-heterocyclic nitrenium (NHN) ion acts as a photocatalyst under visible light to produce benzylboronates directly from aroyl chlorides in the absence of metals or additives. A large variety of aroyl chlorides are well tolerated under the reaction conditions. Mechanistic investigations and density functional theory calculations support that NHN species are involved in the radical formation and the DMAc-H2O/B2cat2 contributes to the formation of alkylboronates.

Herein, S-scheme heterojunctions were successfully constructed by loading MOF-derived NiS2 and CuS nanosheets onto hollow CuS. The photocatalytic hydrogen production of H-CuS/NiS2@CuS composites can reach 17.66 mmol g−1 h−1. The excellent photocatalytic hydrogen evolution performance can be attributed to the interfacial electric field of S-scheme heterojunction, which effectively promotes the separation of photogenerated electrons and holes, thus promoting the hydrogen evolution reaction.

Heterojunction engineering is regarded as one of the most efficacious means to enhance the hydrogen evolution performance of photocatalysts. In this research, bimetal MOF-74 is grown on hollow Cu7S4, and after vulcanization, H-CuS/NiS2@CuS is obtained to form heterostructures. The experimental results indicate that the synthesized H-CuS/NiS2@CuS has an outstanding photocatalytic hydrogen evolution rate of 17.66 mmol g−1 h−1, and its photocatalytic hydrogen evolution performance is much higher than that of single transition metal sulfide. Within the S-scheme heterojunction, the interfacial electric field causes a significant accumulation of photoelectrons on the conduction band of NiS2. Thus, it can maintain a high reducing property in the hydrogen evolution reaction and remarkably boosts the separation efficiency of photoelectrons and holes. This research offers a feasible scheme for the synthesis of highly efficient heterojunction photocatalysts.

The method for the stereoselective formation of dioxabicyclo[3.3.1]nonene structure has been developed. The intriguing bicyclic skeleton is embedded in hybrid-type pyranonaphthoquinone natural products,  e.g., glenthamine Treatment of nanaomycin D and naphthol with Na2HPO4 in DMSO and water affords the bicyclic compound in good yield. The scope of the nucleophilic units and a plausible reaction mechanism has been discussed.

A concise method for the construction of dioxabicyclo[3.3.1]nonene framework has been developed. This structural motif has recently been identified in hybrid-type pyranonaphthoquinone-class natural products. The reaction proceeds in a stereoselective manner under mild conditions. In conjunction with this study, the scalable total syntheses of nanaomycins A and D have been achieved. Based on extensive screening of reaction conditions and nucleophiles, a plausible reaction mechanism is proposed.

CH H bonds (HB) are normally much weaker than those involving the OH group. Quantum chemical calculations address the sorts of substituents, and their placement, that might adjust the strengths of the OH··N and CH··N HBs to make them more nearly equal.

The ability of the CH group to act as proton donor is now widely accepted, even if the H bonds (HBs), which it forms are typically much weaker than those of the hydroxyl group, particularly for a sp3-hybridized C. An NH3 nucleophile is allowed to approach both the terminal methyl group and the hydroxyl of n-butanol, so as to form either a CH··N or OH··N HB. Density functional theory calculations show that the latter is much stronger than the former. However, the strength of the CH··N HB can be amplified and approach much closer to that of OH··N by appropriate placement of suitable electron-withdrawing and donating substituents on the butanol. The interaction energy of the CH··N HB reaches above 6–8 kcal mol−1 in several cases, considerably larger than the prototype HB within the water dimer.

Gold catalysts direct anthranil/diynamide reactions: PPh3AuCl/AgNTf2 forms spiro azacycles (indole intermediate confirmed), while P(t-Bu)2(o-biphenyl)AuCl/AgNTf2 yields indene carboximidamides via a proposed mechanism.

Gold-catalyzed reactions between anthranils and diynamides have been investigated, and their reaction chemoselectivity relies on the types of gold catalysts. With the same anthranil/diynamide mixtures, the use of PPh3AuCl/AgNTf2 leads to formation of spiro azacyclic compounds, whereas P(t-Bu)2(o-biphenyl)AuCl/AgNTf2 preferably yields 1-imino-1H-indene-3-carboximidamides instead. In the PPh3AuCl/AgNTf2 system, an indole intermediate at low temperature for X-ray diffraction study is isolated; this isolable indole species requires anthranil and gold catalyst for efficient formation of spiro azacyclic products. In the case of P(t-Bu)2(o-biphenyl)AuCl/AgNTf2, the mechanism of its resulting 1-imino-1H-indene-3-carboximidamides is postulated based on literature reports.

A kinetically stable Wheland intermediate of the electrophilic aromatic substitution at ferrocene is isolated from the reaction of the diferrocenylphosphenium ion with the allene 2-(trimethylsilyl)-2,3-pentadiene and fully characterized.

The reaction of the diferrocenylphosphenium ion with four terminal allenes follows two different pathways, via allyl or vinyl carbocations, which proceed with electrophilic substitution reactions at one ferrocenyl moiety to form persistent Wheland intermediates and eventually alkenyldiferrocenylphosphonium salts. The reaction of the diferrocenylphosphenium ion with 2-(trimethylsilyl)-2,3-pentadiene affords a stable Wheland intermediate of ferrocene in high yields, which is isolated and fully characterized.

The reaction of dipotassium germoldiides with donor complexes of AlCl3 reveals an astonishing broad line-up of products. Key products are Ge(II)alumole complexes, cationic germole complexes of aluminylenes, and a 2H-germole derivative. Product formation is influenced by the choice of the donor, its size and its stoichiometric ratio.

The reactivity analysis of dipotassiumgermoldiides K2 [1] with aluminum trichloride in the presence of donors uncovers an unexpectedly broad range of products. The specific product formed varies, based on the donor's characteristics, its size, and the stoichiometric ratio between the donor and the aluminium trichloride. This leads to the formation of various products, including alumole complexes of germanium 3(Do) (with Do = OEt2, iPr2Me2Im), cationic germole complexes of aluminylenes [14]+, and 2H-germole derivatives such as 15a. The alumole complexes of germanium 3 are structurally best described as nido-type clusters or aluminagerma[5]pyramidanes. They show significant Lewis acidity and can be isolated only in the form of their donor complexes 3(Do). The 2H-germole derivative 15a promises a high synthetic potential due to its unprecedented germenide (R2C = Ge(:)-R) group group, which is part of a butadiene system and substituted with a reactive C-Al functionality.

An indole synthesis via an allenyl ester intermediate at ambient temperature has been developed. The mild reaction conditions allow the use of a broad range of substrates. Notably, the utility of this approach is demonstrated through the asymmetric total synthesis of geissoschizoline, a Strychnos-type monoterpenoid indole alkaloid. This synthesis highlights a novel strategy for accessing monoterpenoid indole alkaloids.

Methyl indole-2-acetate is a key structural motif in plant-derived indole alkaloids. In this study, a mild and efficient protocol is presented for its preparation using readily available aniline derivatives, which are synthesized from malonic esters. The reaction proceeds via an allenyl ester intermediate, with NaCN-mediated indole formation occurring at ambient temperature, affording high yields and broad substrate scope. The synthetic utility of this approach is demonstrated through the asymmetric total synthesis of geissoschizoline, a Strychnos-type monoterpenoid indole alkaloid. This synthesis not only establishes a novel route to monoterpenoid indole alkaloids but also achieves complete stereochemical control in constructing the six chiral centers of the natural product.