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Organocatalyzed highly enantioselective direct aldol reactions of aldehydes with hydroxyacetone and fluoroacetone in aqueous media: the use of water to control regioselectivity.
Chemistry. 2007; 13(2):689-701.C

Abstract

An organocatalyst prepared from (2R,3R)-diethyl 2-amino-3-hydroxysuccinate and L-proline exhibited high regio- and enantioselectivities for the direct aldol reactions of hydroxyacetone and fluoroacetone with aldehydes in aqueous media. It was found that water could be used to control the regioselectivity. The presence of 20-30 mol% of the catalyst afforded the direct aldol reactions of a wide range of aldehydes with hydroxyacetone to give the otherwise disfavored products with excellent enantioselectivities, ranging from 91 to 99% ee, and high regioselectivities. Aldolizations of fluoroacetone with aldehydes mediated by 30 mol% of the organocatalyst in aqueous media preferentially occurred at the methyl group, yielding products with high enantioselectivities (up to 91% ee); however, these additions took place dominantly at the fluoromethyl group in THF. Optically active 3,5-disubstituted tetrahydrofurans and (2S,4R)-dihydroxy-4-biphenylbutyric acid were prepared by starting from the aldol reaction of hydroxyacetone. Theoretical studies on the role of water in controlling the regioselectivity revealed that the hydrogen bonds formed between the amide oxygen of proline amide, the hydroxy of hydroxyacetone, and water are responsible for the regioselectivity by microsolvation with explicit one water molecule as a hydrogen-bond donor and/or an acceptor.

Authors+Show Affiliations

Key Laboratory for Asymmetric Synthesis and Chirotechnology of Sichuan Province, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, 610041, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17013967

Citation

Chen, Xiao-Hua, et al. "Organocatalyzed Highly Enantioselective Direct Aldol Reactions of Aldehydes With Hydroxyacetone and Fluoroacetone in Aqueous Media: the Use of Water to Control Regioselectivity." Chemistry (Weinheim an Der Bergstrasse, Germany), vol. 13, no. 2, 2007, pp. 689-701.
Chen XH, Luo SW, Tang Z, et al. Organocatalyzed highly enantioselective direct aldol reactions of aldehydes with hydroxyacetone and fluoroacetone in aqueous media: the use of water to control regioselectivity. Chemistry. 2007;13(2):689-701.
Chen, X. H., Luo, S. W., Tang, Z., Cun, L. F., Mi, A. Q., Jiang, Y. Z., & Gong, L. Z. (2007). Organocatalyzed highly enantioselective direct aldol reactions of aldehydes with hydroxyacetone and fluoroacetone in aqueous media: the use of water to control regioselectivity. Chemistry (Weinheim an Der Bergstrasse, Germany), 13(2), 689-701.
Chen XH, et al. Organocatalyzed Highly Enantioselective Direct Aldol Reactions of Aldehydes With Hydroxyacetone and Fluoroacetone in Aqueous Media: the Use of Water to Control Regioselectivity. Chemistry. 2007;13(2):689-701. PubMed PMID: 17013967.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Organocatalyzed highly enantioselective direct aldol reactions of aldehydes with hydroxyacetone and fluoroacetone in aqueous media: the use of water to control regioselectivity. AU - Chen,Xiao-Hua, AU - Luo,Shi-Wei, AU - Tang,Zhuo, AU - Cun,Lin-Feng, AU - Mi,Ai-Qiao, AU - Jiang,Yao-Zhong, AU - Gong,Liu-Zhu, PY - 2006/10/3/pubmed PY - 2006/10/3/medline PY - 2006/10/3/entrez SP - 689 EP - 701 JF - Chemistry (Weinheim an der Bergstrasse, Germany) JO - Chemistry VL - 13 IS - 2 N2 - An organocatalyst prepared from (2R,3R)-diethyl 2-amino-3-hydroxysuccinate and L-proline exhibited high regio- and enantioselectivities for the direct aldol reactions of hydroxyacetone and fluoroacetone with aldehydes in aqueous media. It was found that water could be used to control the regioselectivity. The presence of 20-30 mol% of the catalyst afforded the direct aldol reactions of a wide range of aldehydes with hydroxyacetone to give the otherwise disfavored products with excellent enantioselectivities, ranging from 91 to 99% ee, and high regioselectivities. Aldolizations of fluoroacetone with aldehydes mediated by 30 mol% of the organocatalyst in aqueous media preferentially occurred at the methyl group, yielding products with high enantioselectivities (up to 91% ee); however, these additions took place dominantly at the fluoromethyl group in THF. Optically active 3,5-disubstituted tetrahydrofurans and (2S,4R)-dihydroxy-4-biphenylbutyric acid were prepared by starting from the aldol reaction of hydroxyacetone. Theoretical studies on the role of water in controlling the regioselectivity revealed that the hydrogen bonds formed between the amide oxygen of proline amide, the hydroxy of hydroxyacetone, and water are responsible for the regioselectivity by microsolvation with explicit one water molecule as a hydrogen-bond donor and/or an acceptor. SN - 0947-6539 UR - https://www.unboundmedicine.com/medline/citation/17013967/Organocatalyzed_highly_enantioselective_direct_aldol_reactions_of_aldehydes_with_hydroxyacetone_and_fluoroacetone_in_aqueous_media:_the_use_of_water_to_control_regioselectivity_ L2 - https://doi.org/10.1002/chem.200600801 DB - PRIME DP - Unbound Medicine ER -
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