Author
Shengde Wu
Other affiliations: Purdue University, University of Indianapolis
Bio: Shengde Wu is an academic researcher from Indiana University. The author has contributed to research in topics: Enantioselective synthesis & Catalysis. The author has an hindex of 5, co-authored 6 publications receiving 800 citations. Previous affiliations of Shengde Wu include Purdue University & University of Indianapolis.
Papers
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473 citations
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TL;DR: In this article, the use of Schiff base substrates in amino acid synthesis is briefly reviewed, and a new active catalyst species is proposed for asymmetric PTC alkylation of active methylene compounds.
197 citations
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TL;DR: In this article, improved processes for the enantioselective synthesis of α-amino acids are described, which involve combinations of solvents, highly-mixed and low-temperature reaction conditions, and novel catalysts.
Abstract: Described are improved processes for the enantioselective synthesis of α-amino acids which involve combinations of solvents, highly-mixed and low-temperature reaction conditions, and novel catalysts. Also described are novel catalysts and precursors to α-amino acid derivatives.
121 citations
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25 citations
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24 Aug 1994
TL;DR: In this article, improved phase-transfer catalyzed processes for the higher-yield enantioselective synthesis of precursors for alpha-alkyl amino acids are described.
Abstract: Described are improved phase-transfer catalyzed processes for the higher-yield enantioselective synthesis of precursors for alpha-alkyl amino acids. The alpha-alkylation of N-blocked amino acid esters is carried out with alkyl chlorides or bromides (and benzyl analogues thereof) using novel quaternary ammonium derivatives of chinchonine and chinchonidine. These novel enantioselective catalysts comprise N-substituted, O-substituted cinchoninium or cinchonidinium chlorides or bromides, or 3a,3b-dihydro N-substituted, O-substituted cinchoninium or cinchonidinium chlorides or bromides, where the N-substituent is alkylaryl, and wherein the alkyl contains 1-5 carbon atoms and the aryl has up to thirty carbons, and the O-substituent is alkyl or alkenyl, each having up to about ten carbon atoms. Also involved in this improved process is the use of combinations of solvents, high-speed mixing and below ambient temperatures. The novel precursor starting materials for the alpha-alkyl amino acids are also described.
6 citations
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1,378 citations
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TL;DR: Michael reaction of malonates to nitrooleolefins with chiral bifunctional organocatalysts, bearing both a thiourea and tertiary amino group, afforded Michael adducts with high yields and enantioselectivities.
Abstract: Michael reaction of malonates to nitroolefins with chiral bifunctional organocatalysts, bearing both a thiourea and tertiary amino group, afforded Michael adducts with high yields and enantioselectivities (up to 95%, up to 93% ee).
1,202 citations
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TL;DR: This review describes developments in the burgeoning field of asymmetric ion-pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction.
Abstract: Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion-pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction.
751 citations
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710 citations
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694 citations