E-resources
Peer reviewed
-
Clemente, Fernando R; Houk, K. N
Journal of the American Chemical Society, 08/2005, Volume: 127, Issue: 32Journal Article
The effects of different amino acid catalysts and substrate substituents on the stereoselectivity of the title reactions have been studied with the aid of density functional theory methods. Experimental data available in the literature have been compiled. B3LYP/6-31G(d) calculations match the general experimental trends and provide useful insights into the origins of the variations in stereoselectivities. Acyclic primary amino acids allow a greater conformational flexibility in the aldol transition states compared with proline. This makes them poorer enantioselective catalysts with triketone substrates with a methyl ketone side chain. The steric repulsion upon substitution at the terminal methyl group increases the energy difference between anti- and syn-chairs with primary amino acid catalysts and, consequently, the stereoselectivities. Proline, in contrast, is a poor catalyst for the latter reactions because the substituent's steric bulkiness raises the activation energy of the favored C−C bond-forming pathway.
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Shelf entry
Permalink
- URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year | Impact factor | Edition | Category | Classification | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Select the library membership card:
If the library membership card is not in the list,
add a new one.
DRS, in which the journal is indexed
Database name | Field | Year |
---|
Links to authors' personal bibliographies | Links to information on researchers in the SICRIS system |
---|
Source: Personal bibliographies
and: SICRIS
The material is available in full text. If you wish to order the material anyway, click the Continue button.