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The combination of a catalytic amount of InCl3 and acetic anhydride remarkably promotes the Knoevenagel condensation of a variety of aldehydes and activated methylene compounds. This catalytic system accommodates aromatic aldehydes containing a variety of electron-donating and -withdrawing groups, heteroaromatic aldehydes, conjugate aldehydes, and aliphatic aldehydes. Central to successfully driving the condensation series is the formation of a geminal diacetate intermediate, which was generated in situ from an aldehyde and an acid anhydride with the assistance of an indium catalyst.

Ptn (n = 12, 13) clusters are synthesized with atomic-level precision by using a dendrimer ligand as the macromolecular template.

A new and convenient method to prepare tetraalkylated anthracenes and pentacenes as well as dialkyldiaryl analogues is reported.

A new convenient method for the synthesis of the title compounds (V) and (IX) and the thiophene-containing picene derivative (XIII) is developed.

Novel acrylic monomers bearing a monosaccharide residue were synthesized in reactions of some methyl glycosides with 2-hydroxylethyl acrylate or methacrylate in the presence of heteropoly acid. All of them were highly soluble in water and readily polymerized by radical initiators.

[PPh4]3[Cd2(CN)7] contains a novel mineralomimetic discrete [Cd2(CN)7]3– anion which is topologically similar to the pyrosilicate anion, Si2O76–.

The structure of CePd2Al3 has been studied by single-crystal X-ray diffractometry and was refined to the R(Rw) values 0.035(0.028). The CePd2Al3 compound crystallizes in hexagonal symmetry belonging to the space group P6/mmm; the lattice constants are: a = 5.4764(2) A , c = 4.2187(2) A . It is corroborated that the structure is a CaCu5-type derivative, with Pd and Al atoms, respectively, replacing the Cu atoms on two crystallographically distinct structure sites. An occupational refinement of the atom sites indicated the presence of an appreciable proportion of vacant sites (ca. 4%) at the Pd position.

The Friedel-Crafts acylation of 1-acetylindoline with (S)-2- or (R)-2-(methanesulfonyloxy)propionyl chloride, and aluminum chloride in dichloromethane at room temperature did not afford the expected (S)- or (R)-1-acetyl-5-[2-(methanesulfonyloxy)propionyl]indoline, but gave optically pure (R)- or (S)-1-acetyl-5-(2-chloropropionyl)indoline, whose stereochemistry at the asymmetric carbon was inverted during the reaction. Similar reaction of 1-acetylindoline with the same chiral acylating agents in the presence of aluminum bromide gave mainly the corresponding 2-bromopropionyl derivatives, but as stereo mixtures.

Ru-catalyzed arylation of benzoic acid esters with electron-rich arylboronates proceeds regioselectively at the ortho-position to give sterically hindered benzoates, e.g. (III), (V) in good yields.

The synthesis, isolation and preliminary characterization of all-carbon [60]fullerene dimers C121 and C122 are reported.

In the presence of a catalytic amount of a zirconium-bis(binaphthol)methane complex (5), Mannich-type reactions of aldimines with silyl enolates proceeded smoothly to afford the corresponding adducts in high yields with high enantiomeric excesses. (R)-(R)-Bis(3-BINOL)methane 6, that was prepared by linking two binaphthols, was shown to be very effective in these reactions.

We report the isolation and characterization of the bisfullerene C 121, the first all-carbon molecule to contain a homofullerene (also called a fulleroid) cage. This unsymmetrical isomer of C121 ,along with a symmetrical isomer of C121 and C122, were obtained by thermolysis of a mixture of C60CBr2 and C60 and separated by high performance liquid chromatography. The predominant isomer of C121 has a spiro carbon atom bridge that connects to one of the cages through an open (5.6) ring junction (i.e., between a pentagon and a hexagon) and to the other through a closed (6.6) ring junction. Ab initio calculations indicate that the unsymmetrical structure is more stable than either of the symmetrical alternatives, with the bridging carbon atom attached to both C60 cages through closed (6.6) ring junctions or attached to each cage through open (5.6) ring junctions. Experimental evidence for the unsymmetrical structure comes from the 13 C NMR and UV/vis spectra. Electrochemical reduction of this bisfullerene shows three pairs of distinct, reversible peaks that correspond to each of the first three reductions of the (60)fullerene cages. This is consistent with the presence of a homofullerene unit and shows the similarity of the redox behavior to that of C60. The first reduction potential of C121 is slightly shifted toward more positive values than that of (60)fullerene.

The Yb 2 Cu 2 In compound with the tetragonal Mo 2 B 2 Fe structure has been prepared using a high-pressure technique. The lattice volume is found to be considerably larger than that expected for the system with usual Yb 3+ configuration. The temperature dependence of the magnetic susceptibility and the electrical resistivity shows that this system is almost non-magnetic. These results indicate that the Yb ion in this system is very close to the divalent state.

A new method for the synthesis of multiarylanthracenes was developed by means of the RuH2(CO)(PPh3)3-catalyzed arylation of anthraquinone with arylboronates. This method consists of short and straightforward sequences starting with an easily accessible anthraquinone and is applicable to the syntheses of various multiarylanthracenes including those bearing twisted backbones.

A new method for the synthesis of dihydropyridin-2-ones from various N-2-nitrobenzenesulfonyl (nosyl) imines and 1,3-diethoxy-1-trimethylsiloxy-l,3-butadiene (Brassard's diene) under weakly-basic conditions is described. This synthesis of dihydropyridin-2-ones involves the initial addition reaction of Brassard's diene to imines to afford the adducts followed by a cyclization reaction that forms the corresponding 4-ethoxy-5,6-dihydro-1H-pyridin-2-ones in moderate to good yields after deprotection of its nosyl group from the adducts.

Carbohydrate glycosyl acceptor and donor moieties were synthesized efficiently by using the fluorous tag method. The p-alkoxyphenyl-type heavy fluorous tag was stable under all the reaction conditions used in the preparation of the various carbohydrate units. Each synthetic intermediate carrying the fluorous tag could be obtained in a simple straightforward manner by partition between fluorous and organic solvents.

We investigated antiferromagnetic transitions of R 5 lr 4 Si 10 (R = Tb, Dy, Ho, Er) by measuring the low-temperature specific heat. The antiferromagnetic transition temperature T N is precisely determined. T N is l0.7 K for R = Tb, T N is 5.8 K for R = Dy, T N is 5.1 K for R = Ho and T N is 3.5 K for R = Er, respectively. These results suggest that the antiferromagnetic transition of the ternary rare-earth metal silicide R 5 lr 4 Si 10 is dominated by the exchange interaction between R 3+ ions like as the antiferromagnetic transitions in the ternary rare-earth metal compounds RCu 2 Ge 2 (R = rare-earth metal). In addition, we report the upturn of the specific heat below 1.5 K observed for R = Tb and Ho.

Aza-Diels-Alder type reactions of various imines with 1-methoxy-3-trimethylsilyloxy-1,3-butadiene (Danishefsky's diene) derivatives catalyzed by Lewis bases such as lithium methoxide are described. The reaction proceeds via a stepwise pathway, i.e. first by an imino-aldol reaction followed by the acid mediated annulation to afford the corresponding 2,3-dihydropyridin-4-ones in high yields. An appropriate choice of the substituents on nitrogen plays important roles both in addition of the silyl enolates and in the subsequent annulation to form the desired cycloadducts.

Alkoxy anion such as methoxide anion works effectively as Lewis base catalyst to activate silicon-carbon bond of 1-methoxy-3-trimethylsilyl-oxy-1,3-butadiens (Danishefsky's dienes) in the reaction between aldehydes and ketones. By using Lewis base as catalyst, acid sensitive substrates and Lewis basic moiety containing substrates can be used in this reaction. The hetero Diels-Alder type reaction proceeds through stepwise mechanism between silyl enolates and carbonyl compounds.

A lithium methoxide-catalyzed hetero Diels–Alder reaction of aromatic and aliphatic aldehydes with 1-methoxy-3-trimethylsilyloxy-1,3-butadiene (Danishefsky’s diene) is described. It proceeds throug...

Side chain dynamics of right-handed α-helical poly(γ-benzyl L -glutamate) (PBLG) was investigated by solid state 2 H NMR. Two main motional modes composed of the large amplitude motions and the rapid and small-amplitude librations along the side chain were extracted from line shapes and T 1 data above the glass-like transition temperature. The motional correlation times and amplitudes of the former are widely distributed, showing the heterogeneity of the side chain region. The phenyl rings at the end of the side chain also undergoes π-flipping. This reorientation is slightly restricted in the racemic complex of PBLG and its enantiomer, left-handed α-helical poly(γ-benzyl D -glutamate), in which phenyl rings from each L and D polymer are considered to stack regularly. The large amplitude motions and the librations are rather restricted in the stack state. About 75% of the side chain participate in the stacking. It is noted that the stacking structure is very flexible on the NMR time scale and the model for the ‘static’ stacks of the phenyl rings should be modified.

We describe the HPLC separation and identification of N@C60 and N2@C60. These species were observed after eleven sequential HPLC separations. Their retention times are in the same range as those of the other noninteractive endohedral species of C60, such as noble gas endohedral C60. The separation factors of these endohedrals were evaluated by using a mixture of hexane/toluene as eluent. We note that this is the first evidence for the N2@C60 molecule existing in the form of endohedral C60 complex.

The isolation of a new fullerene dimer, C122H4, and its structural characterization by 13C NMR and 1H NMR spectroscopy and by UV/vis and IR spectroscopy are reported. The structure of this dimer consists of two fullerene cages, which are directly connected through two C−C bonds and two methylene bridges. Consequently, adjacent hexagonal faces of the two fullerene cages are arranged in a face to face manner. Molecular orbital calculations indicate that the proximity of the fullerene cages results in significant through space overlap in both the HOMO and LUMO. As a consequence of this overlap, the electrochemistry of the dimer shows electronic communication with stepwise reduction of each cage.