Coordination chemistry of phosphole ligands: From supramolecular assemblies to OLEDs

The synthesis and properties of organophosphorus π-conjugated chromophores incorporating metallic ions are described. Their optical and electrochemical properties depend on the metal centre linked to the organophosphorus atom. Moreover, the introduction of metallic ions induces a control of the supramolecular organization of the organophosphorus π-conjugated systems. The specific properties of these complexes make them valuable materials for organic light-emitting diodes and interesting building blocks for the tailoring of novel NLO-phores.     

The chemistry of naphthazarin derivatives

In water-containing organic solvents 2-oxo-2,3-dihydronaphthoquinone derivatives are hydrated to give the corresponding 2,2-dihydroxy-2,3-dihydronaphthoquinones. The hydration is reversible; in some cases, a keto-gem-diol equilibrium is established. The susceptibility of 2-oxo-2,3-dihydronaphthoquinone derivatives for hydration depends on the donor-acceptor properties of substituents at C(3), C(6), and C(7), on whether or not hydroxy groups are present at C(5) and C(8), and on the organic solvent basicity. For Part 5, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 3, pp. 465–470, March, 2000.     

海南新碱衍生物的化学

海南新碱及其异己烯基取代的海南新碱是通过分子间区域选择性环化反应获得。取代海南新碱在不同条件下的还原可得一系列4-甲基戊烯或4-甲基戊烷海南新碱衍生物, 用化学关联, 光谱分析和X-射线衍射确立了它们的立体化学。     

The chemistry of naphthazarin derivatives

Direct oxidation of naphthazarin with manganese dioxide in conc. H₂SO₄ was found to be a simple and effective method for the synthesis of mompain. For Part 3, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1019–1021, May, 1999.     

The chemistry of naphthazarine derivatives

Based on IR and¹H and¹³C NMR spectroscopic studies, the oxidation product of echinochrome with Ag₂O was assigned the structure of 2,3-epoxy-7-ethyl-2,3-dihydro-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone. For part 4, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1607–1609, August, 1999.     

The chemistry of naphthazarin derivatives

The 7,7′-dideoxy analog of islandoquinone, binaphthazarin of a new structural type, bearing a 2-oxo-2,3-dihydro-1,4-naphthoquinone moiety was synthesized. The carbonyl group at the C(2) atom of this binaphthazarin easily adds water to give the correspondinggem-diol. Comparison of the spectral characteristics of the prepared diol and islandoquinone made it possible to elucidate more precisely the structure of the latter.     

De-aromatizing phosphole

Quantum-chemical DFT calculations using the B3LYP functionals have been carried out for 1-R-substitued phospholes and some 1-R-substitued 3,4-dimethylphospholes where R = H, Me, Ph, CN, OH, OMe, F, Cl, and Br. The aromaticity of the phospholyl rings is interpreted as a function of geometric, magnetic, and energetic indexes. It is shown, in agreement with previous experimental results, that phosphole aromaticity does not correlate with pyramidality at phosphorus. Variation of hyperconjugative and, to a lesser extent, conjugative effects is responsible for the change in cyclic delocalization for the phospholes studied here.     

The chemistry of 2,3-dihydroisoxazole derivatives

Methods for the synthesis and transformations of 2,3-dihydroisoxazole derivatives are reviewed. Data on reduction and oxidation reactions and intramolecular rearrangements are generalized; their mechanisms are discussed.     

The chemistry of organoimido derivatives of polyoxometalates

The chemistry of organoimido derivatives of polyoxometalates (POMs) has received increasing interest. In recent decades, a great development of the synthetic chemistry of organoimido derivatives of POMs using different imido-releasing reagents has taken place, particularly the novel DCC-dehydrating protocol to prepare organoimido derivatives of POMs was developed recently by us and co-workers. Organoimido substituted POMs as valuable building blocks can construct novel nanostructured organic-inorganic hybrid molecular materials in well-developed common organic synthesis methods, such as Pd-catalyzed carbon-carbon coupling and esterification. Therefore, the reactive chemistry of organoimido derivatives of POMs stands for the fascinating future of the chemistry of organoimido derivatives of POMs.     

The chemistry and biology of organic guanidine derivatives

Organic guanidine compounds are reviewed, with emphasis on natural products isolation, identification, synthesis and biological activities. The literature survey includes purely synthetic guanidine derivatives, guanidine alkaloids and non-ribosomal peptides from bacteria and cyanobacteria, as well as related compounds isolated from marine and terrestrial invertebrates and higher plants.     

8-Phosphabicyclo[3.2.1]octanes—III4: The reaction between oxyallyl cations and phosphole derivatives

The reaction of oxyallyl cations with phosphole sulfide as well as phosphole oxides was investigated and was found to give the expected 8-phosphabicyclo[3.2.1]octanic system (2, 4 and 7) apart from other unexpected products (3 and 5). In the case of the phosphole sulfide (1), the oxyallyl cation is believed to react preferentially with the P=S group, rather than the dienic moiety, leading to a P=S to P=O transformation or to a very particular reaction resulting in 5. This occurs through an intermediate (j) in which a C=S group reacts in a [2 + 4] cycloaddition with the phosphole as a diene. The structure and stereochemistry of the various products were established by the aid of their spectral data in conjunction with spectral data of some related compounds. A formal PhPO elimination is believed to occur through an intermediate phosphinate resulting from Bayer-Villiger like oxidation, which then loses the [PhPO₂] group.Phosphole sulfide (1), previously found to react as a dienophile, was shown to enter a [2 + 4] cycloaddition as a diene with powerful dienophiles like 4-methyl-1,2,4-triazoline-3,5-dione (10).     

Click chemistry with fullerene derivatives

C₆₀ derivatives bearing either terminal alkyne or azide functional groups have been prepared and used as building blocks under the copper-mediated Huisgen 1,3-dipolar cycloaddition conditions leading to 1,2,3-triazole derivatives.     

Modular synthesis of benzo[b]phosphole derivatives via BuLi-mediated cyclization of (o-alkynylphenyl)phosphine

Treatment of an (o-alkynylphenyl)phosphine with a stoichiometric amount of BuLi effects a cyclization reaction to produce a 3-lithiobenzo[b]phosphole, which affords a variety of 3-substituted benzophospholes upon reaction with electrophiles. An example is given for the synthesis of a bis-benzo[b]phosphole, which can be further converted to the corresponding benzo[b]phosphole oxide possessing high electron affinity.     

The important role of the phosphorus lone pair in phosphole aromaticity

Calculations on phosphole systems using the G3MP2B3 model chemistry show that the phosphorus lone pair is critical to the system's aromaticity. Protonation of the lone pair results in antiaromatic molecules as measured by homomolecular homodesmotic reactions. Attempts to separate out effects of hyperconjugation on the butadiene portion of the system are unsuccessful with current practices. Because these hyperconjugation effects will tend to cancel each other in the phosphole systems, analyses using the unmodified homomolecular homodesmotic reactions are considered reasonable measures of their aromaticity. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:754–758, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20364     

鬼臼毒素衍生物的量子化学研究

对若干个鬼臼毒素衍生物进行了量子化学计算,根据其电子结构及有关分析结果,结合它们对体外L1210白血病细胞生长的抑制活性(IC50),讨论了它们的活性部位及构效关系,发现具有较高活性的化合物分子中有三个重要部位：C4位为有效的修饰位点;B环及E环是重要的活性部位,其中B环是接受电子的主要活性部位,其正电性越高,活性越强;E环及其4'位酚羟基氧的负电性越高,活性越强。     

Researches on the chemistry of carbazole derivatives

A method of preparing a number of 9-(-alkoxyethyl)-carbazoles by adding carbazole to the corresponding simple vinyl ethers in the presence of acid catalysts is described. Data relating to the effects of various factors on the reaction are given. The synthetic method developed for 9-(-alkylhydroxyethyl) carbazoles differs from that previously used in that reaction conditions are milder, yields of vinyl ethers lower, and yields of products higher.