Abstract
Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 333-336 |
| Number of pages | 4 |
| Journal | Tetrahedron Letters |
| Volume | 50 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2009 Jan 21 |
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Keywords
- Amination
- Chiral auxiliary
- Reversal of stereoselectivity
ASJC Scopus subject areas
- Biochemistry
- Drug Discovery
- Organic Chemistry
Cite this
Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones : the metal enolate-dependent synthesis of two possible hydrazide diastereomers. / Chao, Chin Sheng; Cheng, Chung Kai; Li, Ssu Hsien; Chen, Kwunmin.
In: Tetrahedron Letters, Vol. 50, No. 3, 21.01.2009, p. 333-336.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones
T2 - the metal enolate-dependent synthesis of two possible hydrazide diastereomers
AU - Chao, Chin Sheng
AU - Cheng, Chung Kai
AU - Li, Ssu Hsien
AU - Chen, Kwunmin
PY - 2009/1/21
Y1 - 2009/1/21
N2 - Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.
AB - Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.
KW - Amination
KW - Chiral auxiliary
KW - Reversal of stereoselectivity
UR - http://www.scopus.com/inward/record.url?scp=57149132089&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57149132089&partnerID=8YFLogxK
U2 - 10.1016/j.tetlet.2008.11.003
DO - 10.1016/j.tetlet.2008.11.003
M3 - Article
AN - SCOPUS:57149132089
VL - 50
SP - 333
EP - 336
JO - Tetrahedron Letters
JF - Tetrahedron Letters
SN - 0040-4039
IS - 3
ER -