Shinpei Miyamoto

Synthesis, structure and magnetic behaviour of dinuclear uranium(IV) complexes with a ‘calixsalophen’ type macrocycle

Treatment of UCl4 with the octadentate tricompartmental ‘calixsalophen’ type macrocycle H4L1 [N,N:N′,N′-bis(2,2′-dihydroxy-3,3′-dimethylidene-5,5′-di-tert-butylbiphenyl)benzene-1,2-diamine] in THF or pyridine gave the complexes [U2L1Cl4] (1) and [U2L1Cl4(py)2] (2), respectively. The crystal structures of 1·4THF and 2·3py are centrosymmetric, the metal atoms occupying the N2O2 cavities with either a pentagonal bipyramidal environment in 1, two Cl atoms being in apical positions, or a dodecahedral environment in 2. Reaction of U(acac)4 (acac = MeCOCHCOMe) with H4L1 in THF did not afford the corresponding acetylacetonate product but gave instead the isomeric complex [U2L1(acac)4] (3), in which one of the two N2O2 cavities is empty, one of the uranium atoms occupying the central O4 site. The dinuclear complex [U2(HL3)(acac)5] (4) was obtained by treating U(acac)4 with H4L1 in pyridine; in this case, the macrocyclic ligand L1 was transformed into its mono(benzimidazole) derivative L3. The eight-coordinate uranium atoms in 3·5THF and 4·2py adopt a distorted square antiprismatic configuration. The magnetic properties of compounds 1 and 3 were investigated.

Medium-size cyclophanes, 68. Synthesis and bromination of 1,2-dimethyl[2.3]metacyclophan-1-enes

McMurry cyclisation of 1,3-bis(3-acetyl-5-tert-butyl-2-methoxyphenyl)propane (4) afforded anti- and syn-1,2-dimethyl[2.3]metacyclophan-1-enes 5, which were converted to the corresponding 1,2-bisbromomethyl[2.3]metacyclophan-1-enes (8) by treatment with excess BTMA Br3.

Synthesis of 4,16-dimethoxy-1,2-dimethyl[2.4]metacyclophan-1-ene and 8,17-dimethoxy-1.2-dimethyl-10-thia[2.3.4](1,3,5)cyclophan-1-ene

McMurry cyclisation of 1,4-bis(3-acetyl-4-methoxyphenyl)butane afforded flexible 4,16-dimethoxy-1,2-dimethyl[2.4] metacyclophan-1-ene, which was converted to the corresponding triple bridged 8,17-dimethoxy-1,2-dimethyl-10-thia[2.3.4](1,3,5)cyclophan-1-ene. The conformational studies of these cyclophan-1-enes in solution are also described.

Medium-size cyclophanes, 691 Synthesis and ipso-nitration of di-tert-butyl-1,2-dimethyl[2.10]metacyclophan-1-enes

Syn-5,21-di-tert-butyl-1,2-dimethyl[2.10]metacyclophan-1-ene syn-4 was prepared by the McMurry reaction of 1,10-bis(3-acetyl-5-tert-butyl-2-methoxyphenyl)decane 3, and nitrated with fuming nitric acid to give the two-fold ipso-nitration product syn-5 in good yield.

Direct introduction of bromine onto the bridged methylene of 5,13-di-tert-butyl-8,16-dimethyl[2.2]metacyclophane

Treatment of 5,13-di-tert-butyl-8,16-dimethyl[2.2]metacyclophane 1 with 1,3-dibromo-5,5-dimethylhydantoin (DBMH) in CH2Cl2 led to the first successful introduction of bromine onto the bridged methylene group.

Medium-sized cyclophanes. Part 72. Synthesis and structures of 9-methoxy(1,4)naphthaleno[3.3]metacyclophane-2,11-diones

Syn- and anti-9-Methoxy(1,4)naphthaleno[3.3]MCP-2,11-diones (4) are obtained by the coupling reaction of 2,6-bis[2-cyano-2-(toluenesulfony)ethyl]anisoles (2) and 1,4-bis(bromomethyl)naphthalene (3) in dimethylformamide (DMF) with an excess of sodium hydride.

Synthesis and structures of 8-benzyl[2.2]metaparacyclophanes

A convenient preparation of 8-benzyl[2.2]metaparacyclophanes using TiCl4 catalysed Friedel–Crafts benzylation of arenes with 8-bromomethyl[2.2]metaparacyclophane is described. The structures of these novel 8-benzyl[2.2]meta-paracyclophanes in solution are also discussed.

Synthesis and structural properties of novel calixarene analogues having Schiff base units

Novel calixarene analogues having Schiff base units have been synthesised by condensation reaction of the bisaldehyde with o-phenylenediamines in the presence of boric acid. The present calixarene analogues form hydrogen bonds between imine nitrogen and phenol hydrogen with 1,2-alternate conformation, confirmed by X-ray crystallography.