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38 results on '"Dong, Kuiyong"'

17. AgI‐Catalyzed Reaction of Enol Diazoacetates and Imino Ethers: Synthesis of Highly Functionalized Pyrroles.

Author

Dong, Kuiyong, Humeidi, Ahmad, Griffith, Wendell, Arman, Hadi, Xu, Xinfang, and Doyle, Michael P.

Subjects
*ETHER synthesis, *PYRROLES, *ENOL ethers, *BENZOXAZOLES, *DIPYRROMETHANES, *ETHERS
Abstract

An unprecedented AgI‐catalyzed efficient method for the coupling of imino ethers and enol diazoacetates through a [3+2]‐cycloaddition/C−O bond cleavage/[1,5]‐proton transfer cascade process is reported. The general class of imino ethers that includes oxazolines, benzoxazoles and benzimidates are applicable substrates for these reactions that provide direct access to fully substituted pyrroles with uniformly high chemo‐ and regioselectivity. High variability in substitution at the pyrrole 2‐, 5‐ and N‐positions characterizes this methodology that also presents an entry point for further pyrrole diversification via facile modification of resulting N‐functional pyrroles. [ABSTRACT FROM AUTHOR]

Published
2021
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24. Strain‐Induced Nucleophilic Ring Opening of Donor–Acceptor Cyclopropenes for Synthesis of Monosubstituted Succinic Acid Derivatives.

Author

Marichev, Kostiantyn O., Wang, Kan, Greco, Nicole, Dong, Kuiyong, Chen, Jinzhou, Lei, Jinping, and Doyle, Michael P.

Subjects
SUCCINIC acid, ACID derivatives, NUCLEOPHILES, METAL carbenes, CATALYSIS, ACETAMIDE, DIAMIDES
Abstract

1,2,3‐Trisubstituted donor–acceptor cyclopropenes (DACPs) generated in situ from enoldiazo compounds react with nucleophiles to form α‐substituted succinic acid derivatives in high yields. Initial dirhodium(II) carboxylate catalysis rapidly converts enoldiazo‐acetates or ‐acetamides to DACPs that undergo catalyst‐free Favorskii ring opening with amines, and also with anilines, alcohols, and thiols, when facilitated by catalytic amounts of 4‐dimethylaminopyridine (DMAP). This methodology provides easy access to mixed esters and amides of monosubstituted succinic acids, including derivatives of naturally occurring compounds. It also affords dihydrazide, dihydroxamic acid, and diamide derivatives, as well as α‐substituted tetrahydropyridazine‐3,6‐diones in high yields. Attempts to generate optically enriched DACPs were not successful because their populations having the R and S configurations formed with a chiral dirhodium catalyst are quite similar, and the loss of enantiocontrol likely originates from the DACP ring forming step which is reversible with its intermediate metal carbene. [ABSTRACT FROM AUTHOR]

Published
2021
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35. Selective Synthesis of-Lactams via Catalytic Metal Carbene C-H Insertion Reactions

Author

Dong, Kuiyong, Qiu, Lihua, and Xu, Xinfang

Abstract

-Lactam, with its unique four-membered ring structure, is an irreplaceable motif in antibacterial medicines, and the diversity synthesis of monocyclic -lactam becomes a very effective approach for the discovery of new pharmacological properties and bioactivities. During the last few decades, efforts have been spent on the chemical synthesis of -lactams, including approaches via metal catalysis and organocatalysis. In this review, progresses in catalytic intramolecular metal carbene insertion reaction for the -lactams structure construction during the last two decades are demonstrated, which emphasize the chemo-, diastereo- and enantioselectivity advances in these transformations of diazo compounds with structural diversity. And a few of selected initial researches led to significant advances are also mentioned in this article.

Published
2016

36. Editorial.

Author

Dong Kuiyong

Published
2014

37. Strain-Induced Nucleophilic Ring Opening of Donor-Acceptor Cyclopropenes for Synthesis of Monosubstituted Succinic Acid Derivatives.

Author

Marichev KO, Wang K, Greco N, Dong K, Chen J, Lei J, and Doyle MP

Subjects
Amines chemistry, Catalysis, Cyclopropanes chemistry, Succinates chemical synthesis, Succinic Acid chemistry
Abstract

1,2,3-Trisubstituted donor-acceptor cyclopropenes (DACPs) generated in situ from enoldiazo compounds react with nucleophiles to form α-substituted succinic acid derivatives in high yields. Initial dirhodium(II) carboxylate catalysis rapidly converts enoldiazo-acetates or -acetamides to DACPs that undergo catalyst-free Favorskii ring opening with amines, and also with anilines, alcohols, and thiols, when facilitated by catalytic amounts of 4-dimethylaminopyridine (DMAP). This methodology provides easy access to mixed esters and amides of monosubstituted succinic acids, including derivatives of naturally occurring compounds. It also affords dihydrazide, dihydroxamic acid, and diamide derivatives, as well as α-substituted tetrahydropyridazine-3,6-diones in high yields. Attempts to generate optically enriched DACPs were not successful because their populations having the R and S configurations formed with a chiral dirhodium catalyst are quite similar, and the loss of enantiocontrol likely originates from the DACP ring forming step which is reversible with its intermediate metal carbene., (© 2020 Wiley-VCH GmbH.)

Published
2021
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38. Synthesis of Chiral Tetrasubstituted Azetidines from Donor-Acceptor Azetines via Asymmetric Copper(I)-Catalyzed Imido-Ylide [3+1]-Cycloaddition with Metallo-Enolcarbenes.

Author

Marichev KO, Wang K, Dong K, Greco N, Massey LA, Deng Y, Arman H, and Doyle MP

Abstract

The all-cis stereoisomers of tetrasubstituted azetidine-2-carboxylic acids and derivatives that possess three chiral centers have been prepared in high yield and stereocontrol from silyl-protected Z-γ-substituted enoldiazoacetates and imido-sulfur ylides by asymmetric [3+1]-cycloaddition using chiral sabox copper(I) catalysis followed by Pd/C catalytic hydrogenation. Hydrogenation of the chiral p-methoxybenzyl azetine-2-carboxylates occurs with both hydrogen addition to the C=C bond and hydrogenolysis of the ester., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2019
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