Milan Dzurilla

Spirocyclization strategy toward indole phytoalexins. The first synthesis of (′)-1-methoxyspirobrassinin, (′)-1-methoxyspirobrassinol, and (′)-1-methoxyspirobrassinol methyl ether

Abstract The first syntheses of cruciferous indole phytoalexins (±)-1-methoxyspirobrassinin, (±)-1-methoxyspirobrassinol, (±)-1-methoxyspirobrassinol methyl ether as well as a new syntheses of phytoalexins (±)-spirobrassinin and cyclobrassinin were achieved by dioxane dibromide (DDB)-mediated spirocyclization of brassinin and its 1-substituted derivatives.

NEW SYNTHESES OF INDOLE PHYTOALEXINS AND RELATED COMPOUNDS

Abstract Synthesis of indole phytoalexins brassinin, brassitin, cyclobrassinin and related compounds via 3-aminomethylindole and its 1-substituted derivatives obtained by nickel boride catalyzed reduction of corresponding aldoximes with sodium borohydride and via [1-( t -butoxycarbonyl)-indol-3-yl]methyl isothiocyanate, the first stable derivative of indol-3-ylmethyl isothiocyanate is described. Antifungal activity of the prepared compounds was examined by using the fungus Bipolaris leersiae by t.l.c. bioassay and quantitative screening was carried out with the selected compounds.

Preparation and characterization of the complexes Cu(PTU)2Cl, Cu(ETU)2Cl and Cu(BTU)2Cl (PTU: R=phenyl, ETU: R=ethyl, BTU: R=benzyl in CH3CH=CHCONHCSNHR); crystal structure of the Cu(PTU)2Cl complex

Abstract The complexes Cu(PTU) 2 Cl, Cu(ETU) 2 Cl and Cu(BTU) 2 Cl (PTU: R=phenyl, ETU: R=ethyl, BTU: R=benzyl in CH 3 CHCHCONHCSNHR) were prepared by the reaction of CuCl 2 with the corresponding derivates of 2-propenoyl thiourea. The complexes were investigated by the methods of CHN analysis, infrared spectroscopy, 1 H and· 13 C NMR spectroscopy. The crystal structure of Cu(PTU) 2 Cl was determined by X-ray analysis: triclinic space group P 1 , a =15.538(1), b =14.296(2), c =12.016(2) A, α=102.72(1), β=105.95(1), λ=94.31(1)°, D m =1.44(1), D c =1.44 g cm -3 , Z =4, R =0.066. The unit cell of Cu(PTU) 2 Cl contains two centrosymmetrical dimer molecules of the complex (denoted as A and B) with a different coordination sphere of the Cu(I) atoms. In molecule A two atoms of Cu(I) with coordination number 4 are bridged through chloride bridges (CuCl 2.318(2) and CuCl′ 2.762(2) A) and two molecules of PTU are terminally coordinated through the S atoms. In molecule B the bridges are formed by the atoms of S of one PTU molecule (CuS 2.235(2) and CuS′ 2.904(2) A). The other PTU molecule as well as the Cl − anion are terminally bonded. The results of infrared and NMR spectroscopy indicate that the complexes containing ETU or BTU exhibit analogous structure.

A new approach to the synthesis of rare thiazino[6,5-b]indol-4-one derivatives. First total synthesis of the indole phytoalexin cyclobrassinon

Abstract The first synthesis of the indole phytoalexin cyclobrassinon and some of its analogues, possessing a thiazino[6,5- b ]indol-4-one tricyclic ring system was performed starting from 1-substitued 2-chloroindole-3-carboxaldehydes. The route employed the intramolecular Et 3 N-mediated or photochemical nucleophilic substitution of a chlorine atom in the 2-position of the indole ring with a sulfur atom as a key step. Examination of biological activity against the selected tumor cell lines, bacteria and fungi revealed no expressive activity of synthesized compounds.

A new photocyclization approach to the rare 1,3-thiazino[6,5-b]indol-4-one derivatives

The analogs of indole phytoalexin cyclobrassinon have been prepared in four steps from corresponding 1-substituted 2-chloroindole-3-carboxylic acids, employing a hitherto unknown photochemical cyclization of new indolyl thiocarbamates to 1,3-thiazino[6,5-b]indole-4-one derivatives as a key step.

1,3-Thiazino[6,5-b]indol-4-one derivatives. The first synthesis of indole phytoalexin cyclobrassinon

Abstract The first synthesis of indole phytoalexin cyclobrassinon in six steps, in 12% overall yield and some of its analogues, possessing a 1,3-thiazino[6,5- b ]indol-4-one tricyclic ring system was performed, starting from 2-chloroindole-3-carboxaldehyde and employing the intramolecular Et 3 N-mediated nucleophilic substitution of a chlorine atom in the 2-position of an indole ring with sulfur as a key step.