Synthesis of Enantiomerically Enriched Allenes by (−)-Sparteine-Mediated Lithiation of Alkynyl Carbamates
- 29 March 2001
- journal article
- letter
- Published by American Chemical Society (ACS) in Organic Letters
- Vol. 3 (8) , 1221-1224
- https://doi.org/10.1021/ol0157104
Abstract
The α-deprotonation of alkynyl carbamates 3 with the chiral base (−)-sparteine (4)/n-butyllithium, transmetalation with ClTi(OiPr)3, and subsequent substitution with an aldehyde results in the formation of enantioenriched 4-hydroxyallenyl carbamates 11. Stereoselection is determined by dynamic resolution of the lithium/(−)-sparteine complexes by selective crystallization.Keywords
This publication has 19 references indexed in Scilit:
- Solution Structure and Stereochemistry of Alkyl- and Silyl-Substituted Allenyl-Propargyllithium ReagentsJournal of the American Chemical Society, 1999
- Enantioselektive Synthese mit Lithium/(−)‐Spartein‐Carbanion‐PaarenAngewandte Chemie, 1997
- Dynamic resolutions in asymmetric synthesisChemical Society Reviews, 1996
- Convenient Synthesis of Enantiomerically Enriched (Oxybutenyl)stannanes and Their Lewis Acid Catalyzed Homoaldol ReactionsSynthesis, 1996
- Bildung von enantiomerenangereicherten Lithiumindeniden mit (−)‐Spartein — Strukturen, stereospezifische Substitution, Einfluß des LösungsmittelsAngewandte Chemie, 1995
- Synthesis of [R,S;R,S]- and [S,R;S,R]-Bis[2-[1-(dimethylamino)ethyl]ferrocenyl] Diselenides and Their Application to Asymmetric Selenoxide Elimination and [2,3]Sigmatropic RearrangementThe Journal of Organic Chemistry, 1995
- Synthesis of Enantiomerically Enriched Allenes via Chiral, Configurationally Stable 1-Lithio-2-alkynyl CarbamatesSynlett, 1991
- Asymmetrische Homoaldol‐Reaktion durch enantioselektive Lithiierung eines prochiralen 2‐ButenylcarbamatsAngewandte Chemie, 1989
- Highly regio- and syn-diastereoselective synthesis of 4-hydroxy-1,2-alkadienylcarbamates from α-titanatedl 2-alkynylcarbamates and aldehydes1,2Tetrahedron, 1987
- Regio‐ und diastereoselektive Synthese von (4‐Hydroxy‐3‐methyl‐1,2‐alkadienyl)carbamaten aus α‐titanierten 2‐Butinylcarbamaten und AldehydenAngewandte Chemie, 1983