• Bulletin of the Korean Chemical Society
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• 제20권4호
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• pp.441-444
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• 1999

The alkyl Grignard addition reaction on 1-benzyltetrazolylimine proceeds to give N-alkylated products (azophilic addition) and, in contrast, the same reaction on 2-benzyltetrazolylimine produced predominantly C-alkylated products (carbophilic addition). In this report we described theoretical explanations for this experimental finding on the basis of the frontier molecular orbitals and the electrostatic nature of the reactants and the reaction intermediates.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.469-471
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• 1997

• 약학회지
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• 제49권1호
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• pp.20-24
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• 2005

The synthesis of 4',5'-doubly branched carbocyclic nucleosides was accomplished in this study. The selective methylation in the 5'-position was made by Felkin-Anh controlled Grignard addition. The construction of the required 4'-quaternary carbon was carried out by using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs' catalyst II. The natural pyrimidine bases (cytosine, uracil, thymine) were efficiently coupled using a Pd(0) catalyst. When the synthesized compounds were examined for their activity against several viruses such as the HIV-1, HSV-1, HSV-2 and HCMV, the cytosine analogue 13 exhibited weak antiviral activity against the HCMV.

• 약학회지
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• 제47권6호
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• pp.417-421
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• 2003

This paper describes a synthetic route to novel 2'-methyl and 4'-hydroxy carbocyclic nucleosides. The methyl group was successfully installed by carbonyl addition reaction of isopropenyl magnesium bromide followed by ring-closing metathesis and the hydroxy group was directly introduced from carbohydrate chiral template "D-lactose".ose".uot;.

• 대한화학회지
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• 제37권9호
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• pp.826-831
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• 1993

3-Cyanopyridine을 organolithium 나 Grignard 시약과 반응시키면 6-위치에 첨가반응이 일어나 2-치환된 5-cyanopyridine류(6-치환된 3-cyanopyridine류)가 합성되었다. 반면, 2- 또는 4-cyanopyridine을 $CH_3Li$이나 $CH_3Mgl$와 반응시키면, 각각 2-acetylpyridine과 4-acetylpyridine이 합성되었다.

• Bulletin of the Korean Chemical Society
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• 제25권11호
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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.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.366-368
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• 1989

The 3-formyl-2-cephem 4, available from 7-aminocephalosporanic acid has been converted to C-3 vinylic cephems. The reactions involved are the Grignard addition to 4, the conversion of the resulting alcohols to mesylates, and the elimination of the mesyl group by LiCl. When ethylmagnesium iodide is used, only 3-[(E)-1-propenyl] cephem is obtained, which is not easily available by conventional Wittig reaction.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1662-1668
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• 2011

Steric and electronic parameters of 4'-substituents play significant roles in steering the conformation of nucleoside analogues. In order to investigate the relationship of 4'-substituent with antiviral enhancement, novel 4'-phenyl-5'-norcarbocyclic adenosine phosphonic acid analogues were racemically synthesized via de novo acyclic stereoselective route from propionaldehyde 5. The phenyl substituted cyclopentenols 15a and 15b as key intermediates were successfully constructed via reiterative carbonyl addition of Grignard reagents and ring-closing metathesis of corresponding divinyl 14. The synthesized nucleoside phosphonic acids analogues 19, 20, 21, and 23 were subjected to antiviral screening against HIV-1.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.411-416
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• 2011

Steric and electronic parameters of 4'-substituents play significant roles in steering the conformation of nucleoside analogues. In order to investigate the relationship of 4'-group with antiviral enhancement, novel 4'-hydroxymethyl-5'-norcarbocyclic adenosine phosphonic acid analogues were designed and synthesized from 2,2-dimethyl-1,3-dioxolane-4-ethanol (5) using reiterative Grignard addition and ring-closing metathesis (RCM) as key reactions. The synthesized adenosine phosphonic acids analogues (22) and (23) were subjected to antiviral screening against HIV-1. Compound (23) exhibited moderate anti-HIV activity ($EC_50$ = 8.61 ${\mu}M$) in the CEM cell line.

• 약학회지
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• 제48권1호
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• pp.88-92
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• 2004

In this study; a series of 2',4'-doubly branched carbocyclic nucleosides (8,9,10) were synthesized from simple acyclic ketone derivative as starting material. The installation of the 4'-quaternary carbon needed was carried out using a 〔3,3〕-sigmatropic rearrangement. In addition, the introduction of a methyl group in the 2'-position was accomplished by Grig-nard reaction. Bis-vinyl was successfully cyclized using a Grubbs' catalyst II. The natural bases (adenine, cytosine, uracil) were efficiently coupled with the use of a Pd(0) catalyst. Although all the synthesized compounds were assayed against several viruses, only cytosine analogue 9 showed weak antiviral viral activity (EC$_{50}$=45.4 $\mu$M) against CoxB3 virus.s.