• Bulletin of the Korean Chemical Society
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• v.15 no.8
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• pp.644-649
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• 1994

The approximate rates and stoichiometry of reaction of excess dipyrrolinoaluminum hydride (DPAH) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, 0, reagent : compound=4 : 1) were examined in order to define the characteristics of the reagent for selective reductions. The reducing ability of DPAH was also compared with that of bis(diethylamino)aluminum hydride (BEAH). The reagent appears to be stronger than BEAH, but weaker than the parent reagent in reducing strength. DPAH shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and nitriles readily. In addition to that, ${\alpha},\;{\beta}$-unsaturated aldehyde is reduced to the saturated alcohol. Quinone are reduced cleanly to the corresponding 1,4-reduction products. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Both primary and tertiary aromatic carboxamides are converted to aldehydes with a limiting amount of DPAH. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively.

• Archives of Pharmacal Research
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• v.22 no.2
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• pp.194-201
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• 1999

The reaction of thiocyanoacetamide (1) with ${\alpha},{\beta}$-unsaturated ketones 2a,b resulted in the formation of the corresponding newly synthesized 1(H)-pyridinethione derivatives 3a,b. Compounds 3a,b were used as synthons for the preparation of 2-S-alkyl-, 2-S-acetamidopyridine, thieno[2,3-b]pyridine and pyrazolo[3,4-b]pyridine derivatives via a wide range of reactions with different reagents. The antimicrobial activity of some of the newly synthesized compounds was tested. Compounds 3a, 11a, 15a, and 19a,b were found to be the most active ones.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.45-51
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• 1998

A series of bis-aromatic ${\alpha},{\beta}$-unsaturated ketone derivatives with mesaured fungicidal activities in vivo against rice blast(Pyricularia oryzae), tomato leaf blight (Phytophtora infestans) and barley powdery mildew(Erysiphe graminis) were studied by using quantitative structure activity relationship equations. The QSAR model for the activity of phenyl substituents, $1{\sim}11$, clearly reveals three important factors, namely, resonance(R<0), optimal molecular hydrophobicity(${\pi})_{opt.}=0.38$) and optimal distance($((L_{1})_{opt.}=5.69({\AA}))$ of substituent, respectively. But in case of 2-pyridyl substituents, $12{\sim}28$, the activity were governed by optimal molecular refractivity $((M_{R})_{opt.}=8.04{\sim}39cm^{3}/mol)$, steric effect(Es<0) and LUMO energy(e.v). The fungicidal activity relationship of phenyl and 2-pyridyl substituents against Erysiphe graminis have been proportioned.

• Bulletin of the Korean Chemical Society
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• v.25 no.11
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• pp.1687-1691
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• 2004

Regioselectivity on the reactions of ${\alpha},{\beta}$--enones with organoindium such as in situ generated allylindium and allenylindium was systematically studied in the presence of TMSCl as an additive. Treatment of 2-cyclohexen-1-one, carvone, 2-cyclohepten-1-one, and chalcone with allylindium reagent produced 1,4-addition products in good yields, while 2-cyclopenten-1-one, 2-methyl-2-cyclopenten-1-one, 4,4-dimethylcyclohexen-1-one, 3-nonen-2-one, 4-hexen-3-one, and 4-phenyl-3-buten-2-one afforded 1,2-addition products. Indium reagent derived from indium and propargyl bromide in Grignard type gave addition products in good yields, under which the successive addition of ${\alpha},{\beta}$-enone and TMSCl were necessary. Although organoindium reagent derived from propargyl bromide produced propargylated compound in Grignard type except 2-cyclohepten-1-one, indium reagent obtained from 1-bromo-2-butyne having ${\gamma}$-methyl group gave allenylated product inBarbier type.

• Journal of the Korean Chemical Society
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• v.21 no.2
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• pp.108-120
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• 1977

The approximate rates and stoichiometries of the reaction of lithium borohydride, with fifty two selected organic compounds containing representative functional groups under the standard condition (tetrahydrofuran, $0^{\circ}$), were studied.Among the active hydrogen compounds,primary alcohols and compounds containing an acidic proton liberated hydrogen relatively fast, but secondary and tertiary alcohols very sluggishly. All the carbonyl compounds examined were reduced rapidly within one hour. Especially, among the ${\alpha}{\beta}$-unsaturated carbonyl compounds tested, the aldehydes consumed one hydride cleanly, however the cyclic ketones consumed more than one hydride even at $-20^{\circ}$. Carboxylic acids were reduced very slowly, showing about 60% reduction in 6 days at $25^{\circ}$, however acyl chlorides reduced immediately within 30 minutes. On the other hand, the reductions of cyclic anhydrides proceeded moderately to the hydroxy acid stage, however the further reductions were very slow. Aromatic and aliphatic esters, with exception of the relatively moderate reduction of acetate, were reduced very slowly, however lactones were reduced at a moderate rate. Epoxides reacted slowly, but amides and nitriles as well as the nitro compounds were all inert to this reagent. And cyclohexanone oxime and phenyl isocyanate were reduced very sluggishly. Last of all, all sulfur compounds studied were inert to this hydride.