Regio- and diastereoselective reactions of chiral secondary alkylcopper reagents with propargylic phosphates: preparation of chiral allenes

• Published in: Chemical science (Cambridge) Vol. 11; no. 2; pp. 5328 - 5332
• Main Authors: Skotnitzki, Juri, Kremsmair, Alexander, Keefer, Daniel, Schüppel, Franziska, Le Cacher de Bonneville, Brieuc, de Vivie-Riedle, Regina, Knochel, Paul
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 28.05.2020; Royal Society of Chemistry; The Royal Society of Chemistry
• Subjects: Chemistry; Chemistry, Multidisciplinary; Configuration management; Phosphates; Physical Sciences; Reagents; Regioselectivity; Science & Technology; Stereoselectivity; EPOXIDES; SYN; ETHERS; CONTINUUM; ENANTIOSELECTIVE SYNTHESIS; AXIAL CHIRALITY
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc05982b

The diastereoselective S N 2′-substitution of secondary alkylcopper reagents with propargylic phosphates enables the preparation of stereodefined alkylallenes. By using enantiomerically enriched alkylcopper reagents and enantioenriched propargylic phosphates as electrophiles anti -S N 2′-substitutions were performend leading to α-chiral allenes in good yields with excellent regioselectivity and retention of configuration. DFT-calculations were performed to rationalize the structure of these alkylcopper reagents in various solvents, emphasizing their configurational stability in THF. The diastereoselective S N 2′-substitution of secondary alkylcopper reagents with propargylic phosphates enables the preparation of stereodefined alkylallenes.