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A rhodium complex derived from RhH(PPh3)4 and Me2PhP catalyzed the carbothiolation reaction of 1-alkylthio-1-alkynes and 1,4-diaryl-1,3-butadiynes giving (Z)-4-alkylthio-4-aryl-3-arylethynyl-3-buten-1-ynes. Terminal alkynes such as 1-decyne and (t-butylthio)acetylene underwent the carbothiolation reaction using a RhH(PPh3)4-dppb catalyst. The reactions proceeded via cis-addition with C–C bond formation at the less hindered acetylene carbon.

New analogues of calix[4]arenetetrasulfonate (1) were prepared, in which the methylene bridges are replaced by S (2) and SO2 (3). The complexation ability of these calixarene ligands 1–3 toward Tb3+ ion and luminescence properties of the resulting complexes were examined. All the ligands formed complexes with lanthanide ions (Pr3+, Sm3+, Eu3+, Tb3+ and Dy3+), among which the Tb3+ complex exhibited strong energy transfer luminescence. The pH dependence of the luminescence intensity suggested that the analogues 2 and 3 possess higher complexation ability towards Tb3+ than the parent 1, which should be ascribed to the higher acidity of the phenolic OH groups as well as the coordinating ability of the bridging groups S and SO2. The composition of the complexes of 2 and 3 was determined to be Tb3+·2 and Tb3+·3 by a molar ratio method. The photophysical properties such as emission lifetimes (τ) and quantum yields (Φ) of the complexes were estimated. Both Tb3+·2 and Tb3+·3 gave comparable τ values (0.7 ms), which are larger than that of Tb3+·(1)2 (0.6 ms). Comparison of their lifetimes in D2O solution suggested that Tb3+·2 and Tb3+·3 have four to five coordinated water molecules responsible for quenching. On the other hand, complex Tb3+·2 gave the largest Φ value (0.15), whereas Tb3+·(1)2 and Tb3+·3 gave very close Φ values (0.12 and 0.13, respectively). The results of this study showed that thiacalix[4]arenetetrasulfonate 2 and the sulfonyl analogue 3 are promising candidates for the scaffold to construct luminescence devices from the viewpoint of the higher complexation ability and luminescent performance.

The dinuclear palladium allyl complexes 7 and 12, which contain tetradentate nitrogen ligands 2 or 3 as bridging ligands, respectively, were synthesized and characterized. Crystal X-ray analysis of these complexes reveal that the two coordination planes of the palladium are twisted, although each of the coordination spheres presents roughly the same structural features as the related (bipyridine)allylpalladium complex.

1,3-Thiaza- and 1,3-selenaza-1,3-butadienes bearing several substituents at the C-2 and C-4 positions were generated through thermal cycloreversion of 6H-1,3,5-oxathiazines or 6H-1,3,5-oxaselenazines, respectively, and the heterodienes were efficiently trapped by using acetylenic dienophiles. When 6H-1,3,5-oxathiazines or 6H-1,3,5-oxaselenazines were heated in the presence of nucleophiles, such as alcohols or thiols, the corresponding 1,4-adducts of the heterodienes with the nucleophiles were obtained in good yields. On the other hand, heating of 6H-1,3,5-oxathiazines or 6H-1,3,5-oxaselenazines in the absence of trapping agents afforded several products which originated from the in situ generated 1,3-chalcogenaza-1,3-butadienes; also the heterodienes were not isolated or observed directly as the monomeric forms at all.

The reaction of cycloheptatriene with dichloroketene, generated by the treatment of trichloroacetyl chloride with activated zinc in dry diethyl ether, affords 9,9-dichlorobicyclo[5.2.0]nona-2,4-dien-8-one 2 as a major product together with 3′,3′,9,9-tetrachlorospiro(bicyclo[5.2.0]nona-2,4-diene-8,2′-oxetan)-4′-one 3. Structure 3 is elucidated by the X-ray crystallographic analysis of its partially reduced product. Lactone 3 exhibits [1,5] hydrogen-migration in the seven-membered ring to give 3′,3′,9,9-tetrachlorospiro(bicyclo[5.2.0]nona-3,5-diene-8,2′-oxetan)-4′-one 7 without any decarbonylation. The reaction of 2 with diazomethane exhibits ring expansion of the four-membered ring to give 1,1-dichloro-3,3a,4,8a-tetrahydroazulen-2(1H)-one 8. 2-Hydroxyazulene 9 is successfully derived by the reaction of 8 with lithium chloride in good yield. The reaction of 8 with triethylamine exhibits dehydrochlorination to give 3-chloro-8,8a-dihydroazulen-2(1H)-one 10 in high yield. N-(Azulen-2-yl)pyrrolidine is also derived from either 9 or 10 in good yield.

The nickel-catalyzed [2 + 2] annulations of electron-deficient allenes proceed efficiently in a highly regioselective manner under very mild conditions to give the head-to-head cyclodimerization products, bismethylenecyclobutanes, as single isomers in good to fair yields. We also carried out the stoichiometric reaction of these allenes in the presence of Ni(0) complexes and elucidated the mechanism of this highly selective reaction.

Pt(0)−enyne π complexes, which could be the platinum analogues of an intermediate in the palladium(0)-catalyzed benzannulation of conjugated enynes, were synthesized, and the structure and reactivity of the complexes were investigated.

Treatment of sterically-crowded bornane-2-selones possessing substituted bornane skeletons with chloramine-T afforded several products originated from intermediary selone Se -imides, and the direct observation of the intermediates was performed by NMR monitoring at low temperature.

The selective de-tert-butylation of p-tert-butyl thiacalix[4]arene (p-tert-butyl TCA) with AlCl3 at 80°C has been investigated. Mono-, di-, and tri-p-tert-butyl thiacalix[4]arene (mono-, di- and tri-TCA, respectively) were obtained in yields of 6.5, 20 and 21%, respectively, when p-tert-butyl TCA was treated with 7.1 equiv. of AlCl3 for 30 min. De-tert-butyl TCA (TCA) was exclusively obtained when 10.5 equiv. of AlCl3 was used. These derivatives are converted to fluorescent active derivatives by modification with dansyl moiety at the lower rim, which are used as metal sensors in aqueous solution. The extent of the fluorescent variations with the metal cations was used to display the sensing factors, ΔI/I0. These hosts show much higher sensitivity for transition metal cations such as Co2+, Ni2+, and Cd2+ than those of alkali metal cations such as Li+, Na+, and K+. The effect of p-tert-butyl groups on metal sensing ability of these hosts was studied. It was found that p-tert-butyl groups decrease the sensing ability of these hosts. It is the first example to show that water soluble TCA derivatives can detect metal cations directly in aqueous solution by variation of fluorescence intensity upon addition of a metal cation.

The first chiral disulfinyldithiacalix[4]arenes have been obtained by oxidation of two adjacent epithio groups of the tetramethyl ether of tetra( p-tert -butyl)tetrathiacalix[4]arene. The chiral resolution was achieved by HPLC using Chiralpak AD as a stationary phase. Furthermore, the absolute configuration of these compounds was determined by X-ray crystallography.

Treatment of p-tert-butylthiacalix[4]arene (1) with benzyl bromide in THF–DMF using NaH as the base catalyst afforded the tetrabenzyl ether of cone conformation (4C) as the major product, oxidation of which, with NaBO3 in CHCl3–acetic acid, proceeded readily to give the corresponding sulfinyl compound (5) with the four SO groups disposed on the same side of the plane defined by the macrocyclic ring probably to avoid the steric hindrance imposed by the benzyllic moieties. Cleavage of the ether bonds gave a new stereoisomer of p-tert-butylsulfinylcalix[4]arene (2(ccc)) with the four SO groups arranged in a cis–cis–cis configuration.

Although the reaction of p-tert-butylphenol with elemental sulfur in the presence of CsOH as a base catalyst yielded a complex mixture comprised of sulfur-bridged phenol oligomers, p-tert-butylthiacalix[6]arene (TC6A) could be isolated in an appreciable yield (0.8%). The X-ray analysis revealed that TC6A adopted a distorted cone conformation stabilized by two sets of hydrogen bondings comprising three phenolic OH groups. The recrystallization from various solvents showed that TC6A had higher inclusion ability toward more guests than TC4A did, suggesting that the expanded central cavity and/or the crystal lattice of the former allowed a more comfortable accommodation of the guest molecules.

A practical method for the synthesis of p-tert-butylthiacalix[4]arene (TC4A), in which the methylene bridges of p-tert-butylcalix[4]arene (C4A) are replaced by epithio groups, is presented by heating a mixture of p-tert-butylphenol, elemental sulfur S8, and NaOH as a base catalyst in tetraethylene glycol dimethyl ether. The inclusion behavior of TC4A for a wide range of solvent molecules is examined by recrystallization, showing preference for the guests depending upon the size and/or the substituent of the guests. The X-ray structure of a 1:2 host–guest complex of TC4A with 1,2-dichloroethane reveals that one guest molecule is included in the cavity of TC4A, while the other is included in the crystal lattice to form a clathrate-type complex. It is shown that the inclusion in the cavity is attained by a cooperative deformation of both the host and the guest.

Optically pure cyclophanes possessing a 1,3-dicarbonyl moiety were conveniently synthesized from alkanedioyl dichloride in four steps. The intramolecular [4+2]cycloaddition of bis(acylketene)s generated by thermal decomposition of bis(4,6-dioxo-1,3-dioxane) proceeded smoothly, giving cyclophane pyranones in high yields. The compounds possessing 7−10 bridging methylenes were resolved by imine formation with (R)-1-phenylethylamine, followed by basic hydrolysis. These cyclophanes are optically active versions of acetylacetone or salicylaldehyde and formed complexes with metals such as copper and europium. X-ray analysis of the chiral copper complex indicated the pentacoordinated structure of the copper metal with syn configuration of the two bridging chains.

T4M (M = Si, Ge, Sn; T = tropolonato)-type compounds were synthesized by reactions of tropolone with tetramethoxysilane, tetramethoxygermane, and tetrachlorostannane, respectively. X-ray and NMR an...

The molecular assembly of thiacalix[6]arene was formed by π–π stacking and π–DMF interactions between thiacalix[6]arene and adjoining thiacalix[6]arene and between thiacalix[6]arene and DMF, respectively. The X-ray crystal analysis also revealed that hydroxyl groups of thiacalix[6]arene adopted novel two sets of hydrogen bond with two DMF and intramolecular hydrogen bond between phenolic units, which cause to make 1,2,3-alternate configuration structure of thiacalix[6]arene.

The largest discrete octadecameric architecture based on a lanthanide ion has been found in the crystal structure of a La{N,N‘-bis(2-pyridylmethyl)-N,N‘-1,2-ethanediylbis(d-alaninate)} complex.

Optically active 2-azanorbornylmethanols and 2-azanorbornylmethanethiol were prepared from ethyl (1 S ,3 S ,4 R )-2-[( R )-1-phenylethyl]-2-azabicyclo[2.2.1]hept-5-ene-3-carboxylate and catalyzed the enantioselective addition of diethylzinc to aldehydes to give optically active secondary alcohols.

Optically active photopyridones possessing synthetic versatility are obtained conveniently by lipase-catalysed enantioselective acylation or hydrolysis of racemic photopyridones, and the absolute configurations are determined by chemical correlation, X-ray crystallographic and CD spectral analyses.

The first silacyclobutadiene complex, (η5-cyclopentadienyl)[η4-1,2-bis(tert-butyldimethylsilyl)-3,4-di-tert-butyl-1-silacyclobutadiene]cobalt (1), was synthesized as red crystals by the reaction of the corresponding 4-silatriafulvene derivative with (cyclopentadienyl)dicarbonylcobalt at 80 °C in benzene. The X-ray analysis of 1 and theoretical calculations for a model silacyclobutadiene complex revealed that the electron accepting ability of the η4-silacyclobutadiene ligand is significantly smaller than that of a cyclobutadiene ligand in the analogous complex.

A novel intramolecular allylic migration from silicon to carbon was observed during the reaction of allylmethyldichlorosilane with tropolone in the presence of triethylamine to give an isomeric mix...

X-ray analysis of the first trigermaallene (3) and 1,3-digermasilaallene (4) revealed that the trimetallaallene skeletons are not linear but significantly bent, similarly to the corresponding trisilaallene 2. In contrast to 2, no dynamic disorder was observed for 3 and 4.

Phenyl- and silyl-substituted ethylene dianion dilithiums, [1-phenyl-1,2,2-tris(trimethylsilyl)ethylene]{bis[(dimethoxyethane)lithium(I)]} (2) and [1,1-diphenyl-2,2-bis(trimethylsilyl)ethylene][tris(tetrahydrofuran)dilithium(I)] (4), were prepared and characterized by X-ray crystallography as well as NMR spectra. The crystal structures of 2 and 4 revealed interesting structural features. One of the lithium cations was located near to the two central carbon atoms, ipso and ortho carbons of the phenyl ring, while the other one was found above the benzene ring. The central C–C bond is twisted by ca. 90° for 2 and ca. 70° for 4.

The intramolecular bissilylation of 3,3,6,6,7,7,10,10-octamethyl-3,6,7,10-tetrasilacyclodecyne (4a) at 110 °C with a catalyst of Pd(OAc)2/1,1,3,3-tetramethylbutyl isocyanide under 5000 bar produced 2,2,2′,2′,5,5,5′,5′ -octamethyl-2,2′,5,5′-tetrasilabicyclopentylidene (5a). 2,2,2′,2′,5,5,5′,5′ -Octamethyl-2,2′,5,5′-tetragermabicyclopentylidene (5b) was also synthesized by the same method. The reaction of 5a with alkali metals (Li, Na, K, Rb, and Cs) in THF gave the corresponding dianion dialkali metals. The structures of 5a, (2,2,2′,2′,5,5,5′,5′-octamethyl-2,2′,5,5′-tetrasilabicyclopentylidene)bis[(tetrahydrofuran)lithium(I)] (6a), and (2,2,2′,2′,5,5,5′,5′-octamethyl-2,2′,5,5′ -tetrasilabicyclopentylidene)bis[(tetrahydrofuran)sodium(I)] (6b) were studied by X-ray crystallography as well as NMR spectroscopic means. The central anionic C–C bond is not twisted for 6a, whereas it is twisted by 17.1° for 6b.

New chiral ligands, 2-azanorbornylmethanols, were prepared and catalyzed the addition of diethylzinc to aldehydes to furnish secondary alcohols in up to 92%ee.

A successful design for the construction of C 20 gibberellin framework has been described. The key features of the synthesis are as follows: (a) Pd 2+ -promoted cycloalkenylation reaction ( 6 → 5 ) and (b) intramolecular Diels-Alder reaction ( 4 → 3 ).

The novel μ-iminosilyl complexes Ru2(CO)4(μ-dppm)(μ-SiTol2)(μ-R‘CHNSiTol2) (2) were obtained in high yields during the stoichiometric reactions of a diruthenium complex having Ru−H−Si interactions, {Ru(CO)2(SiTol2H)}2(μ-dppm)(μ-η2:η2-H2SiTol2) (1), with nitriles R‘CN (R‘ = Me, Ph, t-Bu, CHCH2). The catalytic hydrosilylation of various ketones and imines with dihydrosilanes were achieved using 1 as a catalyst. A novel reaction cycle involving the cooperative functions of the two Ru metals is proposed for the related hydrosilylation of various ketones and imines catalyzed by 1.

Upon irradiation of a stable cyclotrisilene, 1,3,3-tris(tert-butyldimethylsilyl)-2-[tris(tert-butyldimethylsilyl)silyl]cyclotrisilene (5), in toluene with a low-pressure mercury-arc lamp, the isome...

Heating of alkynyl propargyl selenides afforded a stereoisomeric mixture of 5,10-diselenadispiro[3.1.3.1]deca-1,7-dienes. The 1,3-diselenetane rings of the products caused cycloreversion by heating to generate 2-methylene-3-cyclobutene-1-selones and the selones were trapped with diene to give [4+2] cycloadducts.

The titled dication, bis[tris(bicyclo[2.2.2]octeno)tropyliumyl]acetylene dication 3, which is the first example of the acetylene having two tropylium ion units at both ends, has been synthesized by stepwise introduction of the tris(bicyclo[2.2.2]octeno)cycloheptatrienyl unit to acetylene followed by hydride abstraction. The results of X-ray crystallography indicated that the two tropylium rings are twisted with each other by the angle of 44 o and the tropylium rig is slightly bent into a boat form. The dication 3 was neutralized in 50% aqueous acetonitrile via two steps at the pH values of 7.0 and 11.5, which correspond to the pK R+ values of the dication and the half-neutralized monocation, respectively. Thus, the dication 3 is 6 pK R + units destabilized compared with the corresponding monocation due to the intramolecular electrostatic repulsion of the positive charge. The cyclic voltammetry indicated that the dication 3 undergoes two reversible one-electron reductions consecutively in dichloromethane. The electrochemical reduction of 3 as well as chemical reduction with zinc powder in dichloromethane-acetonitrile afforded a blue solution of the corresponding cation radical 3 .+ , but not the diradical, as shown by ESR experiments

The s-cis/s-trans preference of acyclic α,β-unsaturated esters has been studied by their reactions to elucidate the preference in the transition state and by supersonic jet spectroscopy, NOE experiments, and X-ray analysis to clarify the preference in the ground state. It has been rudely accepted that enoate-Lewis acid complexes prefer the s-trans conformation not only in the ground state but also in the transition state of the reactions involving those complexes. The conjugate addition of metal amides to uncomplexed enoates proceeds predominantly through the s-cis conformation, and most organocopper conjugate additions in the absence of Lewis acids or related metal salts take place preferentially in the s-cis conformation

1,2,3,4-テトラ-t-ブチル-1,2,3,4-テトラフェニルシクロテトラゲルマン(3)をベンゼン中,塩化アルミニウム触媒存在下,塩化水素の作用で四官能性の1,2,3,4-テトラ-t-ブチル-1,2,3,4-テトラクロロシクロテトラゲルマン(4)に変換しだ.化合物4は4種の可能な立体異性体中,熱力学的に安定なtrans-の配置であることをX線結晶構造解析によって明らかにした.シクロテトラゲルtマranンs-(t4r)ansをTHF中,金属ナトリウムで縮合させると4,8-ジクロロオクタ-t-ブチルテトラシクロ[3.3.0.02,7.03,6]オクタゲルマン(6)と3,4,7,8-テトラクロロオクタ-t-ブチルトリシクロ[4.2.0.02.5]オクタゲルマン(7)が生成した.ポリゲルマン(7)は2個の四員環がアンチ形に連結したはしご形ポリゲルマンであることをX線結晶構造解析によって明らかにした.

The synthesis of the A,B,C and D ring part 17 of diterpene stemodin (1) from 1,4-cyclohexanedione monoethylene ketal 8 by use of the successive intramolecular Diels-Alder reactions is described.

Three new benzocycloheptenone derivatives, favelol (1), isofavelol (2), and favelone (3), were isolated from the bark of Cnidoscolus phyllacanthus. Their structures were elucidated on the basis of the spectroscopic analysis. Application of the CD exciton chirality method to 4-methoxybenzoates of 1 and 2 led to determination of the R absolute configuration at C-9, which was confirmed by X-ray crystallographic analysis of the 4-bromobenzoyl derivative of 2.

The platinum silyl-substituted η2-disilene complex (Me3P)2Pt[Si(SiMe2(t-Bu))2]2 (4) was synthesized by the reaction of cis-(Me3P)2PtCl2 (5) with 1,2-dilithiotetrakis(tert-butyldimethylsilyl)disilane (6) in THF at −50 °C for 3 h. The X-ray structural analysis revealed that 4 can be regarded as a metalladisilacyclopropane with very weak π-complex character.

The reaction proceeds with 1,3-butadiynes, 1-decyne or (tert-butylthio)ethyne (X) in the presence of RhH(PPh3)4 and an appropriate phosphine ligand.

An adduct formed from 2-trichlorostannyl-3-pentanone and phenylethynyltrichlorotin was isolated, and the structure was determined by spectroscopy and X-ray crystallography. It provides a direct evidence for the carbostannylation of alkynyl metals.

Novel anionic pentacoordinate silicates, p-and m-phenylenebis[trifluoro(phenyl)silicates] and related mono-silicates were synthesized and their structures were determined by means of X-ray crystallography and NMR spectroscopy. Addition of a fluoride ion to a difluoro(phenyl)silyl group caused the significant decrease of the σP+ value as determined by 13C NMR spectroscopy.

The treatment of α,β-unsaturated esters having a ketone function at an appropriate position with either TBDMSOTf in the presence of Et 3 N or TMSI in the presence of (TMS) 2 NH provided, via a tandem intramolecular Michael-aldol reaction sequence, several different types of cyclobutane derivatives. The two reaction conditions were complementary. Tricyclo[4.2.1.03-8]nonanes 34 and 35, tricyclo[5.1.1.0 3,8 ]nonane 40, tricyclo[5.4.0.0 3,7 ]undecane 51, tetracyclo[5.4.0.0 3,7 .0 9,11 ]undecane 45, and the bicyclo[3.2.0]heptanes 36, 57, and 38, which have structures either partially or completely similar to those of endiandric acids A (1a), B (1b), and C (2), trihydroxydecipiadiene (3), lintenone (4), italicene (3), and filifolone (6), were stereoselectively synthesized by the tandem reaction

The crystal structure of 2,6-diethylnaphthalene thiourea adduct was solved by single crystal X-ray diffraction method. The crystal is monoclinic, space group P2l/c, with a = 12.571(3), b = 9.282(2), c = 14.634(3) A, β = 92.14(2)°, V = 1706.3(6) A3 and Z = 2. The final R value was 0.083. The structure was composed of thiourea (host) molecules enclosing channels with hexagonal-prism and 2,6-diethylnaphthalene (guest) molecules in the channels. The cross-section of the channel was deformed hexagon. In the channel, the occupying channel length of the guest molecule was 12.571(3) A

8-Chloro-8-cyano-1,2-homoheptafulvene and its tricarbonyliron complexes have been prepared. Their structures and optical activities were investigated.

The intermolecular contacts between chalcogen atoms and cyano lone pairs were found to stabilize the crystalline state by electrostatic interaction. This interaction is one of the sources of the directionality in crystal paccking of organic molecules and causes the formation of various types of inclusion lattices in the charge-transfer (CT) crystals of I-3. By using highly selective formation of CT crystals with substituted aromatic hydrocarbons, particular isomers such as p-xylene or 2,6-dimethylnaphthalene (2,6-DMN) could be separated from the corresponding isomer mixtures