Synthesis of inosinate trimer I2′p5′I2′pt′I and tetramer I2′p5′I2′p5′I2′p5′I

The trimeric and tetrameric inosinates with (2′–5′)-linkages were synthesized via the phosphotriester approach using the p-nitrophenylethyl group for phosphate protection.     

Highly luminescent gold(I)-silver(I) and gold(I)-copper(I) chalcogenide clusters

The reactions of [AuClL] with Ag(2)O, where L represents the heterofunctional ligands PPh(2)py and PPh(2)CH(2)CH(2)py, give the trigoldoxonium complexes [O(AuL)(3)]BF(4). Treatment of these compounds with thio- or selenourea affords the triply bridging sulfide or selenide derivatives [E(AuL)(3)]BF(4) (E=S, Se). These trinuclear species react with Ag(OTf) or [Cu(NCMe)(4)]PF(6) to give different results, depending on the phosphine and the metal. The reactions of [E(AuPPh(2)py)(3)]BF(4) with silver or copper salts give [E(AuPPh(2)py)(3)M](2+) (E=O, S, Se; M=Ag, Cu) clusters that are highly luminescent. The silver complexes consist of tetrahedral Au(3)Ag clusters further bonded to another unit through aurophilic interactions, whereas in the copper species two coordination isomers with different metallophilic interactions were found. The first is analogous to the silver complexes and in the second, two [S(AuPPh(2)py)(3)](+) units bridge two copper atoms through one pyridine group in each unit. The reactions of [E(AuPPh(2)CH(2)CH(2)py)(3)]BF(4) with silver and copper salts give complexes with [E(AuPPh(2)CH(2)CH(2)py)(3)M](2+) stoichiometry (E=O, S, Se; M=Ag, Cu) with the metal bonded to the three nitrogen atoms in the absence of AuM interactions. The luminescence of these clusters has been studied by varying the chalcogenide, the heterofunctional ligand, and the metal.     

Aluminon I

Ohne Zusammenfassung     

Forging Medium Rings via I(I)/I(III)-Catalyzed Diene Carbofunctionalization

A main-group catalysis-based strategy to access 8-membered carbocycles via the direct carbofunctionalization of 2-phenethyl-substituted 1,3-dienes is disclosed. Through the intervention of an I(I)/I(III) catalysis cycle, the synthesis of densely functionalized, fluorinated benzocyclooctenes can be achieved in an operationally simple manner. Modulating the oxidation/activation regime, and the external nucleophile, the process has been extended to unify the challenging cyclization with formation of allylic C−O, C−N, and C−C bonds (>30 examples). Derivatization of the product benzocyclooctenes is demonstrated together with X-ray conformational analysis, preliminary validation of enantioselective catalysis and a scalable resolution protocol.     

Macrocalyxin I

The title compound, 2‐[1,2,3,4,4a,4b,5,6,7,8,8a,9‐dodeca­hydro‐7‐hydroxy‐4b,8,8‐tri­methyl­phenanthren‐2‐yl]­propenoic acid, C₂₀H₃₀O₃, is a naturally occurring diterpenoid which was isolated from Rabdosia macrocalyx. The hydroxy and carboxy groups, which are located at the two ends of the mol­ecule, both serve as simultaneous hydrogen‐bond donors and acceptors. Two intermolecular O—H?O hydrogen bonds are present and link each mol­ecule to four neighbours, thus forming an extensive hydrogen‐bond network within the crystal.     

Fluorocyclisation of Oximes to Isoxazolines Through I(I)/I(III) Catalysis

A regioselective fluorocyclisation of β,γ-unsaturated oximes through I(I)/I(III) catalysis is disclosed to generate 5-fluoromethylated isoxazolines. The transformation leverages p-iodotoluene as an inexpensive catalyst, Selectfluor® as the terminal oxidant and an amine⋅HF complex (1 : 7.5) as both the fluoride and Brønsted acid source. The λ³-iodane p-TolIF₂, which is generated in situ, engages the pendant alkene of the substrate to facilitate a cyclisation/fluorination sequence. A range of 5-fluoromethyl isoxazolines can be generated using this method, including aliphatic and aromatic systems (up to 56 % yield). Single crystal X-ray analysis of a representative example reveals a conformation that is consistent with the stereoelectronic gauche effect between the exocyclic C(sp³)−F bond and the C(sp³)−O of the isoxazoline (ϕ_OCCF=−62.0°).     

甲状腺肿大率与尿碘、盐碘关系的探讨

为了解甲状腺肿大率与尿碘“分离”现象产生的原因 ,用B超检查甲状腺肿大率 ,用酸消化砷 -铈接触法测定尿碘 ,用直接滴定法测定盐碘。结果表明 ,全市甲状腺肿大率为 7 1% ;尿碘中位数为 2 0 5 5 μg/L ,盐碘中位数为 43 4× 10 -6。甲状腺肿大率与尿碘水平无明显相关性 ,与盐碘浓度也无差异显著性。提示出现病情与尿碘分离现象 ,可能存在其它致甲肿的原因。     

Doubly excited Rydberg states of He I and Ba I

The Auger decay widths of doubly-excited Rydberg states of He I and Ba I have been calculated by the multi-configuration Hartree-Fock procedure. The configuration mixing is crucial in obtaining the correct widths, while the energies seem to be relatively less sensitive to mixing. The usual mixing procedure is often unstable for doubly excited states and careful selection of configurations is required. An improved procedure for selecting the states for mixing is formulated, which seems to stabilize the calculation of both the energies and widths, with small numbers of configurations which are mixed. We apply the recipe to a selected set of doubly excited states of He and Ba. The long standing discrepancies in the widths for the series 7sns, 7snd, 8sns, and 8snd of Ba I withn > 11 may be explained by this procedure, except for the 7snd series. The calculated widths for the 7snd series are larger than the experimental values by a factor of 10–20. The difficulties of treating the states with both electrons in higher Rydberg orbitals are discussed.     

Ligand-unsupported Au(I) chains with short Au(I)...Au(I) contacts

A new series of solids with ligand-unsupported Au(I) chains with short Au...Au contacts were synthesized; as Ag compounds with the same structure are known, the new phases now allow unbiased comparison of Ag...Ag and Au...Au metallophilic bonds not supported by bridging ligands, which shows the latter to be consistently shorter by 0.03-0.04 A.