Shiro Morosawa

The synthesis of 3H-azepines: Thermal reorganization of 2,4- and 3,5-di-t-butyl-3a,5a-dihydro-3H-cyclobuta[b]pyrroles to 2,5- and 3,6-di-t-butyl-3H-azepines

Thermal reaction of cyclobuta [b] pyrroles, which derived by photochemical cyclization of methyl 2,5- and 3,6-di-t-butyl-1H-azepine-1-carboxylate gave di-t-butyl substituted 3H-azepines. The kinetics of the reaction were measured and the activation energy of the reorganization to 3H-azepines was estimated

Ion selectivity control in ester- and amide-armed diaza-crown ethers: sidearm effects in co-operative binding and specific transport

A variety of double-armed diaza-18-crown-6 derivatives were prepared, in which ester-, amide-, and ether-functionalized arms were attached as secondary donor sites. Their cation-binding behaviour was largely dependent on the nature of the donor groups on the flexible arms. Typically, an amide-armed diaza-18-crown-6 derivative enveloped Zn2+ ion in a cryptand-like cavity, while an ester-armed one formed an encapsulated complex with Na+ ion. This type of armed crown ether exhibited characteristic guest-selectivity and high binding dynamics, and provided efficient cation-transport phenomena.

Demethoxycarbonylation of methyl 2,5- and methyl 3,6-dialkyl-1H-azepine-1-carboxylates: formation and characterization of 2H-, 3H- and 4H-azepines

Demethoxycarbonylation of methyl 2,5-di-tert-butyl-1H-azepine-1-carboxylate using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) gave 3H-azepines. Under similar conditions, methyl 3,6-di-tert-butyl-1H-azepine-1-carboxylate gave not only the 3H-azepine but also the isomerized 2H- and 4H-azepines. Application of the reaction to dimethyl and diisopropyl substituted 1H-azepines showed that bulky alkyl group substitution stabilizes the seven-membered azatriene system. The thermal behaviour of the di-tert-butyl substituted azepines is discussed.

Synthesis and photochemistry of 3,6-difluoro-10,11-benzopentacyclo [6,4,0.0,0.0]dodeca-4,10-diene

9,1 2- Difluoro- and 9,12-dichlorotetracyclo[6.4.2.2.0] hexadeca-2,4,6,13,15-pentaene-1 0,1 1-dicarboxylic anhydrides (2a) and (2b) were prepared by 4πs+ 4πs photocycloaddition between cis-3,6-difluoro- or cis-3,6-dichloro-1,2-dihydrophthalic anhydride and naphthalene, respectively. 12,15-Difluoro- and 12,15-dichlorohexacyclo[8.6.0.0.0.0.0]hexadeca-3,5,7-triene-13,14-dicarboxylic anhydrides (6a) and (6b) were obtained by 2πs+ 2πs intramolecular photocycloaddition of adducts (2a) and (2b), respectively. 12,15-Difluorohexacyclo[8.6.0.0.0.0.0]hexadeca-3,5,7,13-tetraene (7a) has been synthesized by the electro-oxidative decarboxylation of anhydride (6a) and the excited singlet naphthalene has been observed on irradiation of adduct (7a), and is presumably formed via an adiabatic pathway.

Synthesis and characterization of 2H-, 3H- and 4H-azepine: the first observation of the thermal distribution equilibrium of azepines

Demethoxycarbonylation of methyl 2,5,-di-tert-butyl-1H-azepine-1-carboxylate using 1,8-diazabicyclo[5.4.0]undec-7-ene gives exclusively two isomers of 3H-azepine derivatives, while methyl 3,6-di-tert-butyl-1H-azepine-1-carboxylate gives a mixture of 2H-, 3H- and 4H-azepine derivatives under the same conditions because of a 1,5-hydrogen shift in the resulting triene system.

Synthesis and characterization of [8] (3,6)azepinophane and [8](3,6) oxepinophanes

[8](3,6)Azepinophane (methyl 3,6-octano-1H-azepine-1-carboxylate) and [8](3,6)oxepinophane (3,6-octanooxepin) were synthesized from bicyclo[8.2.2]undecadiene, and structural features of them were also studied on the basis of their spectral data. The effect of the substituents at 3 and 6 positions on the structure of 1H-azepine ring was elucidated by comparison of several 3,6-dialkyl-1H-azepine derivatives with the title azepinophane

Detection and thermal properties of 1,4-Difluorobenzene-naphthoquinone Biplanemer: A new longicyclic π system

Abstract 9,10-difluorotetracyclo[6.4.2 1,8 .2 9,12 .0 2,7 ]hexadeca-2,4,6,10,13,15-hexaene-3, 6-dione is thermally labile and shows a notably clear, long wave-length CT absorption.

Dimethyl 4-exo,9-endo-dibromobicyclo-[3.3.1]non-2-ene-2,3-dicarboxylate

The bromination reaction of dimethyl bicyclo[3.2.2]nona-6,8-diene-6,7-dicarboxylate, (1b), gave the title compound (2b), C 13 H 16 Br 2 O 4 , and dimethyl 4-exo,9-exo-dibromobicyclo[3.3.1]non-2-ene-2,3-dicarboxylate, (3b). The saturated six-membered ring of (2b) adopts a chair conformation with the Br atom in an equatorial position.

The formation of arvltetralin derivatives in the photolysis of two trans-cinnamoyl moieties at both ends of a polyethylene glycol chain in the presence of lithium perchlorate

A straight forward photochemical route to aryltetralin derivatives 2a, b from a podand system containing a pair of trans-cinnamoyl moieties is reported.

Perkin communications. Amide-armed azamacrocycles as a new series of synthetic carriers for alkali and alkaline earth metal cations

Novel azamacrocycles having amide-functionalized arm groups have been shown to mediate selective and efficient transport of ‘hard’ alkali and alkaline earth metal cations via three-dimensional complexations, while the parent azamacrocycles favour ‘soft’ metal cations.