Ph.D. Project Summary
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This document summarizes research on using axially chiral ligands in asymmetric catalysis. It discusses using ligands like BINAP, Quinap, and Quinazolinap in rhodium-catalyzed hydroborations of olefins. It also examines using Quinazolinap ligands in palladium-catalyzed allylic alkylations and copper-catalyzed beta-boration of alpha,beta-unsaturated esters. Finally, it acknowledges collaborators and outlines future areas of research.
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Ph.D. Project Summary
- 1. Asymmetric Catalysis with Axially Chiral Ligands William Fleming National University of Ireland University College Dublin September 2009
- 7. My Targets: Prepare ligands with electronic diversity at the 7-position. Quinazolinap Ligands
- 9. Quinazolinone: Ligand Synthesis Chlorination of the quinazolinone:
- 10. Suzuki-Miyaura cross coupling: Ligand Synthesis
- 11. Demethylation / Triflation Ligand Synthesis
- 13. Resolution
- 14. Resolution
- 17. Asymmetric Allylic Alkylations Trost, B. et al. Chem. Rev. 2003 , 2921 Optimised conditions:
- 18. Conv.: 100 % Ee: 78 % ( S ) (MW 82 %) Conv.: 100 % Ee: 85 % R=R’=Bu: Conv.: 100 % Ee: 51 % R=H, R’=Ph: Conv.: 100 % Ee: 64 % Conv.: 100 % Ee: 58 % Asymmetric Allylic Alkylations
- 21. Rhodium-Catalysed Asymmetric Hydroborations a Rh(COD)(acac) only, no ligand - 58:42 24 0 Cl 9 a 0 56:44 26 0 Cl 8 11 ( S ) 62:38 100 rt Cl 7 - 42:58 12 0 OMe 6 a 11 ( S ) 51:49 20 0 OMe 5 60 ( S ) 68:32 100 rt OMe 4 - 45:55 30 0 H 3 a 66 ( S ) 83:17 94 0 H 2 65 ( S ) 80:20 100 rt H 1 ee (%) α:β conv. (%) temp. ( o C) X entry
- 22. Rhodium-Catalysed Asymmetric Hydroborations a Ratio of cis:trans β-methylstyrene after 2h reaction time. - 62 ( S ) >99:1 10 0 trans 4 - 68 ( S ) 90:10 72 rt trans 3 75:25 10 ( S ) >99:1 6 0 cis 2 0:100 62 ( S ) >99:1 94 rt cis 1 cis:trans a ee (%) α:β conv. (%) temp. ( o C) substrate entry
- 23. Rhodium-Catalysed Asymmetric Hydroborations 58 ( S ) 91:9 35 0 OMe 4 54 ( S ) 83:17 55 rt OMe 3 60 ( S ) 87:13 70 0 H 2 60 ( S ) 85:15 50 rt H 1 ee (%) α:β conv. (%) temp. ( o C) X = entry
- 24. Rhodium-Catalysed Asymmetric Hydroborations a Ratio of cis:trans stilbene after 2h reaction time. - - 2 0 trans 4 - 20 ( S ) 34 rt trans 3 88:12 - 1 0 cis 2 26:74 30 ( S ) 41 rt cis 1 cis:trans a ee (%) conv. (%) temp. ( o C) substrate entry
- 25. Rhodium-Catalysed Asymmetric Hydroborations 35 ( S ) >99:1 15 0 2 4 64 ( S ) >99:1 70 rt 2 3 57 ( S ) >99:1 100 0 1 2 55 ( S ) >99:1 100 rt 1 1 ee (%) α:β conv. (%) temp. ( o C) n = entry
- 26. Rhodium-Catalysed Asymmetric Hydroborations Guiry, P. J. et al. JOC , 2004 , 6572
- 27. Rhodium-Catalysed Asymmetric Hydroborations Guiry, P. J. et al. JOC , 2004 , 6572
- 29. Copper-Catalysed β -Boration of α , β -Unsaturated Esters
- 30. Asymmetric Boration of Methyl Crotonate. 1 2 3 4 5 6 50 100 6 6 20 95 5 5 13 71 4 4 25 100 3 3 51 65 2 2 40 100 1 1 Ee (%) Conversion (%) Ligand Entry
- 31. Asymmetric Boration of Ethyl Crotonate. 1 2 3 4 5 6 72 100 6 6 34 100 5 5 15 82 4 4 12 99 3 3 40 75 2 2 38 98 1 1 Ee (%) Conversion (%) Ligand Entry
- 32. Asymmetric Boration of i -Butyl Crotonate. 1 2 3 4 5 6 79 100 6 6 35 100 5 5 20 26 4 4 20 100 3 3 42 100 2 2 48 23 1 1 Ee (%) Conversion (%) Ligand Entry
- 33. Asymmetric Boration of t -Butyl Crotonate. 1 5 6 72 100 6 6 42 100 5 5 43 100 1 1 Ee (%) Conversion (%) Ligand Entry
- 34. Quinap in Asymmetric β -Boration of Crotonates 50 % ee 71 % ee 79 % ee 72 % ee Fleming, W. J.; Muller-Bunz, H.; Lillo, V.; Fernandez, E.; Guiry, P. J. OBC 2009 , 2520
- 39. Copper Catalysed β -boration of α , β -Unsaturated Esters Marder et al. Chem. Commun. 2009 , 3987