• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3738-3742
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• 2011

Bismuth tribromide ($BiBr_3$) catalyzed Mannich-type reactions of N-acyliminium ions which generated in situ from N-benzyloxycarbonylamino p-tolylsulfones have been developed. In the presence of catalytic amount of $BiBr_3$, N-benzyloxycarbonylamino p-tolylsulfones prepared from aromatic and aliphatic aldehydes reacted with silyl enol ether and silyl enol ester under mild reaction conditions to afford N-Cbz-protected ${\beta}$-amino ketones and N-Cbz-protected ${\beta}$-amino esters in moderate to good yield, respectively.

• Journal of the Korean Chemical Society
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• v.38 no.12
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• pp.908-914
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• 1994

6a-Hydroxy- and 6a-methoxy-derivatives (1∼6) of octahydro-2,3-dioxo-cyclopenta[b]-pyrrole-3a-carboxylate were synthesized from oxalylation of enamine A, which was prepared from condensation of five-membered cyclic ${\beta}$-keto ester and phenylalkylamine, followed by addition of water or methanol. The formation of heterocyclic ring was assumed to occur by the way of unstable N-acyliminium (B). Stable adduct C (1∼6) was obtained from nucleophilic addition to the endo-ene type pyrrolinium B.

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1623-1628
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• 2002

Tetracyclic pyrido[2,3-b]azepine derivatives 4a-d and 4f as analogues of mirtazapine were synthesized via N-acyliminium ion cyclization by using aromatic rings such as benzene and thiophene ring as a ${\pi}-nucleophile$, and evaluated for the binding affinity for ${\alpha}2-adrenoceptor$. Among tested compounds, 2,3,9,13b-tetrahydro-1H-benzo[f]pyrrolo[2,1-a]pyrido[2,3-c]azepine (4a) was the most potent (Ki = 0.26 ${\mu}M)$ but showed about 3-fold less binding affinity than mirtazapine (Ki = 0.08 ${\mu}M)$ for a2-adrenoceptor.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.350.2-350.2
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• 2002

The reaction of N-acyliminium ion with a variety of nucleophiles is one of the powerful method to introduce various substituents at the a-carbon of an amine. Particularly this type of inter and intramolecular C-C bond formation can be effectively applied to the synthesis of the bioactive natural or unnatural compounds as well as many bioactive peptidomimetics. Accordingly. much attention has been devoted to the practical and efficient methods for the generation of acyliminium ion precursors though there are many important aspects in the reaction involving N-acyliminium ions. (omitted)

• YAKHAK HOEJI
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• v.38 no.1
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• pp.86-90
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• 1994

7,8-Dioxo-A-norerythrinan (A) was synthesized from acid catalyzed cyclization of 6a-hydroxv-1-(2-phenylethyl)-octahydrocyclo-penta[b] pyrrole-3a-carboxylic acid ethyl ester (B) with concomitant deethoxycarbonylation. The intermediate (B) was a hydroxylated compound of N-acyliminium (C). The unstable pyrrolinium (C) was prepared from oxalylation of the enamine of phenethylamine and ethyl 2-oxocyclopentanecarboxylate.

• Bulletin of the Korean Chemical Society
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• v.9 no.3
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• pp.129-132
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• 1988

The stereochemistry of N-acyliminium cyclizations to form decahydropyrrolo[2,1-a]isoquinolin-3(2H)-ones was studied. Particular attention was paid to the stereocontrol by an acetoxy group present on pyrrolidone ring. Two of the three new chiral centers were formed stereospecifically, and the third was controlled by elimination-hydrogenation sequence.

• Bulletin of the Korean Chemical Society
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• v.15 no.4
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• pp.278-279
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• 1994

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.340.2-340.2
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• 2002

As a part of our continuing studies directed toward the synthesis of the medium to macrolactam alkaloids, we have been interested in the versatile functionalization of the lactam carbonyl. Synthetic routes involving cyclic N-acyliminium ions are generally useful strategies that have been applied for a wide variety of synthetic transformation. Especially, the use of a-alkoxy azacycles as precursors to cyclic N-acyliminium ions was well reviewed. (omitted)

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.755-757
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• 2008

A short and highly efficient synthetic method to prepare synthetically useful tetrahydroindolizinone derivatives from the ring-closing metathesis of N-allyl-5-allyl-5-hydroxylactams is described.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1924-1928
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• 2004

Allylations of N-benzyl and N-methyl cyclic imides were accomplished successfully under mild Barbier type conditions using zinc metal, allyl bromide and catalytic amount of $PbBr_2$. Subsequent coupling reactions with some carbon nucleophiles afforded 1,2- and 1,4-addition products in moderate to high yields.