Yuzuru Sanemitsu

Structure-activity relationship of optically active 2-(3-pyridyl)thiazolidin-4-ones as a PAF antagonists

Abstract Two sets of optically active 5-substituted-2-(3-pyridyl)thiazolidin-4-ones, highly potent and selective antagonists of platelet activating factor (PAF), displayed apparently different anti-PAF activities between their enantiomers, wherein these activities depend markedly on the absolute configuration of the 2-position in the thiazolidin-4-ones.

Stereoselective synthesis of anti-PAF active thiazolidin-4-ones via cyclo-condensation of alkyl α-mercaptocarboxylates with arylimines

Abstract Two distinctive methods for the synthesis of cis - and trans -2, 5-disubstituted-thiazolidin-4-ones via stereoselective cyclo-condensation between α-mercaptocarboxylic esters and arylimines have been developed. With the new reaction used as the key step, two sets of optically active anti-PAF active thiazolidin-4-ones were synthesized.

Palladium-catalyzed cyclization reactions. Unique synthesis of condensed thiazoles

Abstract The facile synthesis of 3-methylene-2,3-dihydro-5H-thiazolo-[3,2-c]pyrimidin-5-ones ( 9 ) has been performed by the catalytic action of a Pd(II) salt on 4-propargylthiopyrimidin-2(1H)-ones ( 6 ).Similar Pd(II)-catalyzed cyclization of 3-propargylthio-1,2,4-triazin-5(2H)-ones ( 10 ) gives 6-methylene-6,7-dihydro-4H-thiazolo[2,3-c](1,2,4]-triazin-4-ones ( 11 ) as a main product. 3-Methylene-2,3-dihydro-7H-thiazolo[3,2-b][1,2,4]triazin-7-ones ( 12 ), the regioisomers of 11 are provided by a base-catalyzed cyclization of [ulbar 10].

Palladium-catalyzed cyclization reactions of 3-propargylthio 1,2,4-triazin-5(2h)-ones to thiazolo-1,2,4-triazinones

Abstract Selective transformation of 3-propargylthio-1,2,4-triazin-5(2H)-ones ( 1 ) to 6-methylene-6,7-dihydro-4H-thiazolo[2,3-c][1,2,4]-triazin-4-ones ( 2 ) and 3-methylene-2,3-dihydro-7H-thiazolo[3,2-b]-[1,2,4]triazin-7-ones ( 3 ) is performed under the conditions of Pd(II) salt or sodium hydroxide catalysis, respectively.

Palladium-catalyzed polyhetero-claisen rearrangement of 4-allylthiopyrimidin-2(1h)-ones and 5-allylthio-1,2,4-triazin-3(2h)-ones

Abstract The S → N allylic transposition of 4-allylthiopyrimidin-2(lH)-ones 4 and 5-allylthio-1,2,4-triazin-3(2H)-ones 5 has been performed successfully by catalysis of palladium(II) salts. In both cases the N-alkylated products (6 and 7) are obtained with no traces of the C-alkylated products.

Specific deamination of 4-amino-1,2,4-triazin-5(4H)-ones by catalytic oxidation with t-butylhydroperoxide. A chemical model for metabolism of 1,2,4-triazine herbicides

Abstract The oxidation of 4-amino-1,2,4-triazine herbicides (1) with t-butylhydroperoxide catalyzed by Co(Salen) resulted in the specific deamination of the 4-amino group, providing a chemical model for the metabolism of the herbicides.

A Novel Class of Fungicides: Synthesis of (R)- and (S-) α-Benzylidene-γ-methyl-γ-butyrolactones

The enantiomers of α-benzylidene-γ-methyl-γ-butyrolactones, a novel class of fungicides, were prepared stereospecifically from (R)-and (S)-γ-methyl-γ-butyrolactones. The results of their fungicidal evaluation are also described.