Mikio Yasutake

Synthesis of a new pyridinophane macrocycle with carbamate functionality via novel CO2 insertion reaction

The coupling reaction of 2, 11-diaza[3.3](2, 6)pyridinophane3 and N-tosyl-diethanolamine ditosylate4 in the presence of M2CO3 (M = Cs+, K+) in DMF afforded a novel macrocycle2 with a carbamate moiety, whose structure was confirmed by an X-ray structural analysis. Figure options Download full-size image Download as PowerPoint slide

Remarkable interaction effects of molecular packing on site- and stereoselectivity in photocycloaddition of 2-pyrones with maleimide in the solid state

Abstract Solid-state photoirradiation of 1:1 complex crystals of 4-[ω-(2-furyl)alkyloxy]-6-methyl-2-pyrones 1b, 1c or 4-(ω-arylalkyloxy)-6-methyl-2-pyrones 1d–j with maleimide 2 gave [2+2]cycloadducts 3b–f, 3i, 3j with exclusive stereoselectivity. The high reaction selectivity was confirmed by X-ray structure analyses and MO method of the complex crystals, which were composed of two sets of a 1:1 complex between 1 and 2, arising from an CH–π interaction between 2 and the aromatic rings of 1, and/or π–π stacking between the aromatic rings in addition to four kinds of hydrogen bonding between the ground state 2-pyrone moieties and 2.

A POTASSIUM COMPLEX OF A FLUORINE-CONTAINING MACROCYCLIC CAGE COMPOUND : INTERACTIONS BETWEEN FLUORINE ATOMS AND METAL IONS

A new donor, the C-F unit, can be added to the field of host-guest chemistry. The interaction between fluorine atoms and a potassium ion was proven with the fluorine-containing cage compound 1 as a host. The six fluorine atoms of K+ ⊂1 are coordinated to K+ in a distorted octahedral fashion.

Manganese(III)-based intramolecular macrocyclization of 3,3-diphenyl-2-propenyloxyoligomethylene 3-oxobutanoates

Abstract The reaction of 3,3-diphenyl-2-propenyloxytetramethylene 3-oxobutanoate ( 1 4 ) with manganese(III) acetate dihydrate in boiling acetic acid caused the oxidative intramolecular radical cyclization to produce 13-methyl-11,11-diphenyl-3,8,12-trioxabicyclo[8.3.0]tridec-13-en-2-one ( 2 4 ) in 94% yield. A similar oxidation of the 3,3-diphenyl-2-propenyloxyoligomethylene 3-oxobutanoates ( 1 n : n =2, 3, 6, 8) gave the corresponding macrolides 2 n ( n =2, 3, 6, 8) in moderate to good yields. A 17-membered crown ether-type macrolide 2 11 was also obtained in 80% yield by the intramolacular radical cyclization of the oxaethylene-tethered 3-oxobutanoate ( 1 11 ). The structure of the macrolides 2 n ( n =2, 3, 4, 6, 11) has been corroborated by an X-ray crystal structure analysis.

Catalytic oxidation of 4-piperidone-3-carboxylates with manganese(III) acetate in the presence of 1,1-disubstituted alkenes

Abstract The manganese(III) acetate-catalyzed cycloperoxidation of 4-piperidone-3-carboxylates with 1,1-disubstituted alkenes is described. The 4-piperidone-3-carboxylates reacted with 1,1-disubstituted alkenes in the presence of a catalytic amount of manganese(III) acetate in air at 23°C to give 1-hydroxy-8-aza-2,3-dioxabicyclo[4.4.0]decane-6-carboxylates in good to moderate yields. The crystal structure of the azabicyclic peroxides was determined by an X-ray single crystal analysis. The oxidation of the 4-piperidone-3-carboxylates with 1,1-diphenylethene using a stoichiometric amount of manganese(III) acetate gave ethenyl- and ethyl-substituted 4-piperidones and 6-hydroxy-3-aza-7-oxabicyclo[4.3.0]nonane-1-carboxylate, which was the same as the product obtained from the hydrogenolysis of the 1-hydroxy-8-aza-2,3-dioxabicyclo[4.4.0]decane-6-carboxylate.

Formation and structural features of novel cage compounds with a pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton via photolysis of [33](1,3,5)cyclophane

The photolysis of [3 3 ](1,3,5)cyclophane 8 in MeOH:2N HCl (17:1 v/v) afforded new polycyclic caged dimethoxy and methoxy–hydroxy compounds 12 and 13 with a novel pentacyclo[6.4.0.0 3,7 .0 4,11 .0 5,10 ]dodecane skeleton 7 , in addition to methyl ether 9c with the previously reported skeleton 6 . The unique structural features of 12 and 13 were elucidated by X-ray structural analysis.

Discotic liquid crystals of transition metal complexes 49: establishment of helical structure of fullerene moieties in columnar mesophase of phthalocyanine-fullerene dyads

A homologous series of the phthalocyanine-fullerene dyads, Cn-PcM(OFbaC60) (n = 6, 8, 10, 12; M = Cu, Ni, Co: 3a–3f) have been synthesized to obtain homeotropic alignment at rt and investigate the effects of spacer chain length (n = 6, 8, 10, 12) and central metal (M = Cu, Ni, Co) on the mesomorphism. Interestingly, the shorter-spacer-substituted (n = 6, 8; M = Cu) dyads 3a and 3b showed a hexagonal columnar mesophase (Colh), whereas the longer-spacer-substituted (n = 10, 12; M = Cu, Ni, Co) dyads 3c–3f showed a tetragonal columnar mesophase (Coltet). Moreover, each of the homologs 3a–3e shows perfect homeotropic alignment in both the Colh and Coltet mesophases at rt. More interestingly, these columnar mesophases gave a very unique XRD reflection peak denoted as Peak H in a very small angle region of 0.8 < 2θ < 2.0 degree. We have established at the first time from our developed two new XRD sample preparation techniques that the Peak H is due to the helical structure of fullerenes around columns formed by one-dimensionally stacked Pc cores. 1D nano array structure of donor and acceptor between two electrodes is recently proposed to obtain higher photoelectric conversion efficiency for organic thin film solar cells. This 1D nano array structure is almost compatible with the present homeotropically aligned Pc-C60 dyads 3a–3f between two glass plates. Hence, these novel Pc-C60 dyads 3a–3f may be very suitable to organic thin film solar cells.

X-Ray and MO analysis of highly stereoselective solid-state photocycloadditions of 2-pyrones with maleimide

Abstract Photoirradiations of grinding mixtures of 4-(ω-arylalkyloxy)-6-methyl-2-pyrones 1i–1o and maleimide 2 in the solid state quantitatively gave only a [2+2] cycloadduct 3j with high stereoselectivity. The 1:1 complex crystals 1j · 2 , and 1a · 2 , 1b · 2 , 1c · 2 , 1d · 2 , 1g · 2 , 1h · 2 from another 2-pyrones with 2 , were characterized by powder X-ray diffraction technique. The crystal formation was remarkably affected by polar and bulky nature of the substituents at the aryl groups. Four kinds of hydrogen bondings by two ground state species for the crystals were quantitatively estimated, and the photoreaction mechanism was analyzed to proceed via some interactions of the singlet excited state of 1 with ground state of 2 by MO transition state calculation.

Synthesis of biscalix[4]arene with enhanced binding ability to a cationic guest

Abstract The biscalix[4]arene showed remarkably enhanced inclusion ability for the N-methylpyridinium ion due to the increasing π-basicity of the benzene rings, which interact with the guest in an edge-to-face manner, in calix[4]arene skeletons.

Alternative General Synthetic Routes to [2.2]Cyclophanes and [3.2]Cyclophanes from [3.3]Cyclophane-2,11-diones by Photodecarbonylation, and a Structural Study of [3.2]Metacyclophanes

Photodecarbonylation of [3.3]cyclophane-2,11-diones, which are readily prepared by TosMIC coupling, affords [2.2]cyclophanes in high yield. This method also provides a general synthetic method for [3.2]cyclophan-2-ones by taking advantage of the fact that this photochemical reaction proceeds in a stepwise manner through [3.2]cyclophan-2-ones. A series of [2.2]cyclophanes, [3.2]cyclophanes, and [3.3]cyclophanes can thus be made available from the common precursor [3.3]cyclophane-2,11-diones. In sharp contrast to the preferred syn geometry of [3.3]metacyclophanes, [3.2]metacyclophanes adopt anti geometries and the aryl ring inversion process is observed by variable-temperature 1H NMR spectroscopy. In the crystalline state, the two aryl rings of anti-[3.2]metacyclophanes are almost parallel in spite of the unsymmetrical bridge length; they overlap only at the C-9 and C-17 positions, and the transannular distances are shorter than the corresponding distances in [3.3]metacyclophane-2,11-dione.