Noboru Matsumura

1,4-Dianion of acetophenone N-ethoxycarbonylhydrazone as a synthetic intermediate

Abstract Various β-hydroxyketones and α,β-unsaturated ketones were prepared by the reaction of aldehydes and ketones with 1,4-dianion ( 2 ) which is derived from acetophenone N-ethoxycarbonylhydrazone ( 1 ) with butyllithium. In the reaction of 2 with carbonyl compounds such as ester, amide, acid anhydride, acyl chloride, and alkyl carbonate, pyrazole derivatives were obtained in good yields.

Synthesis of N-substituted oxazoline-2-thione derivatives: reaction of tetraazapentalene derivatives with α-haloketones

Abstract Tetraazapentalene derivatives ( 1 : R=CH 3 , CH 2 =CHCH 2 ) reacted with various α-haloketones to give N-substituted oxazoline-2-thione derivatives ( 2 , 4 , 5 , and 6 ).

Reaction of α-chloroketones with 1,4-dianion of acetophenone n-ethoxy-carbonylhydrazone

Abstract 1,4-Dianion of acetophenone N-ethoxycarbonylhydrazone (2) reacts with α-chloroketones such as phenacyl chloride, 1-chloroacetone, 3-chloro-2-butanone, and 1,3-dichloroacetone to give pyrazoline derivatives in good yields. In the reactions of 2-chlorocyclohexanone and 3-chloro-2-norbornanone with 2, cis-chlorohydrin and exo-chlorohydrin were selectively obtained, respectively.

Synthesis of new azacrown and azathiacrown ethers using a hypervalent sulfur-containing tetraazapentalene as a ring-building block

Abstract New azacrown and azathiacrown ethers ( 5a-c and 7 ), incorporating two thiourea moieties, were synthesized from the hypervalent sulfur-containing tetraazapentalene ( 1 ) and diisothiocyanate derivatives of oligoethylene glycols and from 1 and 3,6,9-trithia-1,11-undecanediisothiocyanate, respectively, by cyclization and then desulfurization.

α-Carboxylation reactions of ketones with a bromomagnesium thioureide–carbon dioxide complex

The magnesium complex (1) has been found to undergo fixation of carbon dioxide and the resulting carboxylato-complex (2) transfers the carboxylato group to several ketones with good yields.

New stable dication of 1,3,4,6-tetrakis(isopropylthio)-2λ4,δ2-thieno[3,4-c]thiophene generated by its oxidation using nitrosonium tetrafluoroborate

The oxidation of 1,3,4,6-tetrakis(isopropylthio)-2λ4,δ2-thieno[3,4-c]thiophene 1 by NOBF4(2 equiv.) gives the dication 2, which reacts with H2O, MeOH and aniline to give the thiophene derivatives 3–5 by fission of the C–S bond of the thieno[3,4-c]thiophene ring; 2 also reacts with 1,2-dimercaptobenzene and NaBH4 to give the adducts 6 and 7 respectively.

Synthesis and characterization of 10-Se-3 type selenatetraazapentalene derivatives with a hypervalent selenium

Abstract Symmetrical 12π-selenatetraazapentalene derivatives 3–5 were synthesized by a convenient one-pot reaction using the lithium selenoureide/phenacyl chloride/alkyl (or allyl) isothiocyanate system. The structure was determined by a single crystal X-ray diffraction of 4. The reactions of 3 and 5 with alkyl iodides and ω-bromoalkyl isothiocyanates gave the novel selenatetraazapentalene derivatives.

Formation of radical cation and dication of 1,3,4,6-tetrakis(isopropylthio)2λ4δ2-thieno[3,4-c]thiophene and their reactions with nucleophiles

1,3,4,6-Tetrakis(isopropylthio)-2λ4δ2-thieno[3,4-c]thiophene 1 formed the complex 2 with I2 in hexane at –30 °C. The ESR spectrum of the complex 2 in MeCN solution showed that the spin densities in the π-electron system are large in the 1-,3-,4- and 6-positions. The complex 2 reacted with amines in MeCN to give the C-C coupling products 4a–c in high yields. The oxidation of 1 with I2 in the presence of aniline in benzene gave the thiophene derivative 5 in a high yield by hydrogen abstraction at the 3-position. The compound 1 was oxidised to its dication by NOBF4. The dication reacted with amines, alcohols and water to give the ring-opening products 10–14 and with thiols and NaBH4 to give the adducts 23–25.

A novel pyrenophane bearing tetraazathiapentalene skeleton

A novel pyrenophane incorporating macrocyclic tetraazathiapentalene is synthesised and characterised. The absorption and fluorescence spectra in CH2Cl2 clearly showed π–π interaction between two pyrene rings including pyrene excimer emission.

Alkoxycarbonyl groups transfer to amines by the N,N′-dibenzyl-and N,N′-di-tert-butyl-carbamates of cyclic thioureas

The use of the dicarbamates of cyclic thioureas as alkoxycarbonyl-transfer reagents for the protection of amino groups is described.