• Journal of Integrative Natural Science
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• v.2 no.3
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• pp.185-189
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• 2009

The new MPV-type reagent, Al-fluorodiisobutylalane (DIBAF), has been prepared and their reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined in order to find out a new reducing system with unique applicability in organic synthesis. In general, the reagent is extremely mild, showing only reactivity toward aldehydes, ketones, and epoxides. The reagent achives a clean 1,2-reduction of enals to the corresponding allylic alcohols in a 100% purity, but shows no reactivity toward enones. The reagent also shows an excellent regioselective cleavage of substituted epoxides. In addition, DIBAF produces the thermodynamically more stable alcohol epimer in high stereoselectivity in the reduction of cyclic ketones.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2915-2920
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• 2013

Convenient synthetic method for 4-arylethylpyrazoles and 4-styrylpyrazoles was developed using ${\alpha}$-alkenyl-${\alpha},{\beta}$-enones readily accessed from the Morita-Baylis-Hillman reaction. For the synthesis of 4-arylethylpyrazole, the reactions with arylhydrazines needed to be carried out in o-dichlorobenzene under $N_2$ balloon atmosphere. On the other hand, 4-styrylpyrazoles required the reactions in ethanol under $O_2$ balloon atmosphere.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.658-662
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• 1990

A method for regioselective mono-carbonylation of halobenzyl halide is described. Alkyl halophenylacetate is easily prepared by carbonylating a benzylic halide of halobenzyl halide in the presence of catalytic amount of cobalt carbonyl, a base, and an alcohol under atmospheric pressure of carbon monoxide. The base plays a decisive role in the selectivity of product and NEt$_3$ is the best one among bases used.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.153-156
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• 2011

A concise synthesis of (${\pm}$)-rhinacanthin A is achieved in two steps by epoxidation of dehydro-$\alpha$-lapachone, followed by chemo- and regioselective reduction. Dehydro-$\alpha$-lapachone was also synthesized in two steps starting from 4-methoxy-1-naphthol by ethylenediamine diaetate (EDDA)-catalyzed benzopyran formation and a CAN-mediated oxidation reaction. $\beta$-Lapachone was synthesized in three steps from 4-methoxy-1-naphthol by benzopyran formation, catalytic hydrogenation, and Jones oxidation. As additional reactions, synthesis of pyranonaphthoquinone derivatives with the pyranokunthone B skeleton has been achieved in a single step from readily available 2-hydroxy-6-methoxy-1,4-naphthoquinone and 2-hydroxy-7-methoxy-1,4-naphthoquinone.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.219-224
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• 2011

The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane ($DIBAO_3SCF_3$), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane ($DIBAO_3SCH_3$) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of $DIBAO_3SCF_3$ appears to be much higher than that of $DIBAO_3SCH_3$, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of $\alpha,\beta$-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl- or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2961-2966
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• 2010

Reduction of carbonyl compounds such as aldehydes, ketones, $\alpha,\beta$-unsaturated enals and enones, $\alpha$-diketones and acyloins was carried out readily with $NaBH_3CN$ in the presence of wet $SiO_2$ as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - $80^{\circ}C$) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.959-965
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• 2005

Investigation of structure-activity relationships of novel quinazolines has identified 7,8-dihydro-[1,4]dioxino-[2,3-g]quinazolines as a potent inhibitor of EGFR. These compounds have a benzodioxane framwork, which was prepared by regioselective O-alkylation of ethyl 3,4-dihydroxy benzoate by epoxide ring opening. Compounds 3f and 3k were more potent than ZD-1839 in EGF enzyme and EGFR autophosporylation inhibition assays.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.859-862
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• 2010

The reactions of ketene dithioacetals with ethane-1,2-diamine, propane-1,3-diamine, 2-aminoethanol, 3-aminopropanol, and 2-aminoethanethiol in ordinary water in the absence of any acid/base catalyst afforded the heterocyclic ketene N,N-, N,O- and N,S-acetals in good yields.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1531-1534
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• 2009

(2S,3R)-3-Hydroxy-2-(hydroxymethyl)-3,6-dihydro-2H-pyridine 8, an important precursor for the synthesis of polyhydroxylated piperidine azasugars, has been prepared from L-serine. Highly stereoselective nucleophilic addition to amino aldehyde 5 gave the corresponding allylic alcohol 6 which proceeded to give dihydro-2H-piridine 7a via a Grubbs II catalyzed RCM. Stereoselective H-bond directed epoxidation of allylic alcohol led to the oxiranyl alcohol 9 which was easily converted to L-deoxyaltronojirimycin by regioselective ring opening.

• Archives of Pharmacal Research
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• v.14 no.4
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• pp.364-369
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• 1991

The synthesis and regioselective reactions of a chiral allyl sulfide. (S)-(+)-(1-methylpyrrolidin-2-yl)methyl allyl sulfide (MAS, 1) are described. Remarkable ${\alpha}-regioselectivity$ was observed in the alkylation of the carbanion of MAS while 1:3 mixtures of ${\alpha}-and\;{\gamma}-adducts$ were produced in the addition of the MAS anion to aldehydes. However, a dramatic change of the regioselectivity was witnessed when Lewis acids such as $Et_3Al$, $Et_3B$, and $Ti(O^iPr)_4$ were used as additives in the addition reaction. In these cases, ${\alpha}-adducts$ were formed exclusively. A rationale for the change of regioselectivity is provided. And the stereochemical aspect of the addition reaction is also described.