Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Study of asymmetric aldol and Mannich reactions catalyzed by proline-thiourea host-guest complexes in nonpolar solvents
Date
2013-04-30
Author
Demir, Ayhan Sıtkı
BAŞÇEKEN, SİNAN
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
172
views
0
downloads
Cite This
A proline-thiourea host-guest complex has been described as a good catalyst for asymmetric reactions such as aldol and Mannich reactions. High stereoselectivities were obtained under optimal conditions. Thiourea was observed to have an important effect on the reactivity and selectivity, even in an unconventional nonpolar reaction medium and without the need to utilize low temperatures. This proline-thiourea host-guest system has the ability to participate in a hydrogen bonding network.
Subject Keywords
Physical and Theoretical Chemistry
,
Inorganic Chemistry
,
Organic Chemistry
,
Catalysis
URI
https://hdl.handle.net/11511/57272
Journal
TETRAHEDRON-ASYMMETRY
DOI
https://doi.org/10.1016/j.tetasy.2013.03.014
Collections
Department of Chemistry, Article
Suggestions
OpenMETU
Core
A new and efficient chemoenzymatic route to both enantiomers of alpha '-acetoxy and alpha '-hydroxy-alpha-methoxy cyclic enones
Demir, Ayhan Sıtkı; Caliskan, Z; Aydin, AE; Bicer, I (Elsevier BV, 2006-03-06)
A chemoenzymatic synthesis of both enantiomers of the pharmacologically interesting alpha'-acetoxy and alpha'-hydroxy-alpha-methoxy cyclic enones starting from alpha-hydroxy cyclic enones is described. Protection of 1,2-diketones, manganese(III) acetate-mediated acetoxylation followed by enzyme-mediated hydrolysis of alpha'-acetoxy enones gives acetoxy enones 3a-d and hydroxy enones 4a-d with high enantiomeric excesses (up to 99%) and good yields. The transesterification of rac-4b in the presence of DMAP af...
Nonlinear effects in proline-thiourea host-guest complex catalyzed aldol reactions in nonpolar solvents
Demir, Ayhan Sıtkı; Eymur, Serkan (Elsevier BV, 2010-03-16)
An aldol reaction catalyzed by a proline-thiourea host-guest complex in a nonpolar solvent shows excellent nonlinear effects. This proline-thiourea system has the ability to form a hydrogen-bonding network. The enantiomeric excess of proline in a solution can be significantly enhanced by its incorporation with a urea molecule into its solid racemate. This suggests a general and facile route to homochirality, which may be involved in the origin of chirality on earth.
A new and efficient chemoenzymatic route to both enantiomers of alpha '-acetoxy-alpha-methyl and gamma-hydroxy-alpha-methyl cyclic enones
Demir, Ayhan Sıtkı; Findik, H; Kose, E (Elsevier BV, 2004-03-08)
A chemoenzymatic synthesis of both enantiomers of the pharmacologically interesting alpha'-acetoxy-alpha-methyl and gamma-hydroxy-alpha-methyl cyclic enones starting from alpha-methyl-beta-methoxy cyclic enones is reported. Manganese(Ill) acetate-mediated acetoxylation followed by the enzyme-mediated hydrolysis of alpha'-acetoxy enone provides acetoxy enones 1a and 2a and hydroxy enones 1b and 2b with high enantiomeric excesses in good yields. The reduction of the acetoxy and hydroxy enones furnished both e...
Reaction of Metal-Carbene Complexes with Cyclobutenediones: The First General C-C Bond Insertion Reaction for Fischer Carbene Complexes
Zora, Metin (American Chemical Society (ACS), 1993-01-01)
Alkylcarbene-chromium complexes react with cyclobutenediones to give 2-alkoxy-4-cyclopentene-1,3-diones in moderate yield, accompanied by varying amounts of 4-cyclopentene-1,3-dione derivatives which result from reduction of the initial product by the chromium byproduct. The reaction is general for a variety of cyclobutenedione derivatives with alkoxy, alkyl, or aryl substituents. The major products of the reaction between arylcarbene complexes and cyclobutenediones are 5-alkylidenefuranone derivatives. A m...
Synthesis of ferrocenyl pyrazoles by the reaction of (2-formyl-1-chlorovinyl)ferrocene with hydrazines
Zora, Metin (Elsevier BV, 2007-10-15)
Synthesis of ferrocenyl-substituted pyrazoles via the reaction between (2-formyl-1-chlorovinyl)ferrocene and hydrazine derivatives is described. Depending upon the substitution pattern of hydrazine, the reaction affords 1-alkyl/aryl-5-ferrocenylpyrazoles and/or 1-alkyl/ aryl-3-ferrocenylpyrazoles. The reaction appears to be general for a variety of hydrazine derivatives.
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
A. S. Demir and S. BAŞÇEKEN, “Study of asymmetric aldol and Mannich reactions catalyzed by proline-thiourea host-guest complexes in nonpolar solvents,”
TETRAHEDRON-ASYMMETRY
, pp. 515–525, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57272.