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Catalytic Enantioselective Fluorination. Teerawat Songsichan 1 st June 2017. Laboratory of Synthesis and Natural Products (LSPN). Content. 1. Introduction 2. Electrophilic Fluorination 2.1 Metal-Catalyzed Fluorination Involving Enolates
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Catalytic Enantioselective Fluorination TeerawatSongsichan 1st June 2017 Laboratory of Synthesis and Natural Products (LSPN)
Content 1. Introduction 2. Electrophilic Fluorination 2.1 Metal-Catalyzed Fluorination Involving Enolates 2.2 Metal-Catalyzed Fluorination Not Involving Enolates 2.3 Organocatalytic Electrophilic Fluorination 2.4 Fluorination Using Multiple Catalysts 2.5 One-Pot and Tandem Processes 3. Nucleophilic Fluorination 4. Summary and Outlook - Catalytic Enantioselective Trifluoromethylation and Perfluoroalkylation - Catalytic Enantioselective Monofluoromethylation - Catalytic Enantioselective Difluoromethylation - Catalytic Enantioselective Trifluoromethylthiolation
Introduction • Impact of Fluorine in Pharmaceuticals • It is well known that fluorine’s electronegativity, size, omniphobicity/lipophilicity, and electrostatic interactions can dramatically influence chemical reactivity. • One of the major effects of fluorination is a modulation of acidity and basicity of a parent compound. This can strongly influence binding affinity, pharmacokinetic properties, and bioavailability of a given drug candidate. • In general, about one-third of the top-performing drugs, currently on the market, contain fluorine atoms in their structures. Atorvastatin (Lipitor) treatment of high cholesterol Fluticasone propionate anti-inflammatory drug Ciprofloxacin (Ciprobay) antibacterial drug Fustero, S.; Soloshonok, V. A.; Liu, H. Chem. Rev. 2013, 114, 2432.
Introduction • Common Fluorinating reagents • Electrophilic reagents • - Elemental fluorine (F2) • - Fluoroxyltrifluoromethane (CF3OF) • - N-Fluoropyridinium salts • - Selectfluor • - N-Fluorobenzenesulfonimide (NFSI) • Nucleophilic reagents • - Ammonium fluoride (e.g. tetrabutylammonium fluoride, TBAF) • - Pyridinium poly(hydrogen fluoride), PPHF (Olah’s reagent) • - DAST [Et2NSF3] / Deoxofluor [(MeOCH2CH2)2NSF3]
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Ti/TADDOL Catalysts Togni, A. Angew. Chem., Int. Ed. 2000, 39, 4359.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Ti/TADDOL Catalysts Togni, A. Beilstein J. Org. Chem. 2011, 7, 1421.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Ti/TADDOL Catalysts Togni, A. Org. Lett. 2003, 5, 1709. Togni, A. Tetrahedron2006, 62, 7180.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Pd/BINAP Catalysts Sodeoka, M. J.Am. Chem. Soc. 2002, 124, 14530.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Pd/BINAP Catalysts Sodeoka, M. Tetrahedron 2006, 62, 7168.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Pd/BINAP Catalysts Sodeoka, M. J. Am. Chem. Soc. 2005, 127, 10164.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Pd/BINAP Catalysts Kim, D. Y. Tetrahedron Lett. 2005, 46, 3115. Kim, A. Y. Org. Lett. 2005, 7, 2309. Kim, S. Y. Tetrahedron Lett. 2013, 54, 3359.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Ni/BINAP Catalysts Sodeoka, M. Angew. Chem., Int. Ed. 2007, 46, 5435.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Cu/Bis(oxazoline) [Box] Catalysts Cahard, D. Tetrahedron: Asymmetry2004, 15, 1007.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Cu and Ni/Bis(oxazoline) [Box] Catalysts Shibata, N.; Toru, T. Synlett2004, 10, 1703.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Zn/Bis(oxazoline) [Box] Catalysts Shibata, N.; Toru, T. Angew. Chem., Int. Ed. 2008, 47, 164.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Involving Enolates • Metal/Bis(oxazoline) [Box] Catalysts • Other substrates: • Other ligands:
Electrophilic Fluorination • Metal-Catalyzed Fluorination Not Involving Enolates • Platinum-Catalyzed Enantioselective Cyclization and C3-Fluorination of Polyenes Substrate product minor product Gagne, M. R. J. Am. Chem. Soc. 2013, 135, 628.
Electrophilic Fluorination • Metal-Catalyzed Fluorination Not Involving Enolates • Palladium-Catalyzed Three-component Coupling of Selectfluor, Styrenes, and Boronic Acids Toste, F. D. J. Am. Chem. Soc. 2014, 136, 4104.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Tertiary Amine Catalysis Shibata, N.; Toru, T. J. Fluorine Chem. 2006, 127, 548.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Tertiary Amine Catalysis Shibata, N.; Toru, T. Angew. Chem., Int. Ed. 2008, 47, 4157. Gouverneur, V. Angew. Chem., Int. Ed. 2011, 50, 8105.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Enamine Catalysis Jørgensen, K. A. Angew. Chem., Int. Ed. 2005, 44, 3703.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Enamine Catalysis Brenner-Moyer, S. E. Org. Lett. 2010, 12, 3356.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Enamine Catalysis MacMillan, D. W. C. J. Am. Chem. Soc. 2011, 133, 1738. Houk, K. N. J. Am. Chem. Soc. 2014, 136, 9556.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • NHC Catalysis Lin, Z.; Sun, J. Angew. Chem., Int. Ed. 2012, 51, 10359.
Electrophilic Fluorination • Organocatalytic Electrophilic Fluorination • Thiourea-Catalyzed Enantioselective Fluorination • Chiral Phosphoric Acid-Catalyzed Enantioselective Fluorination Hu, Y.Adv. Synth. Catal. 2012, 254, 515. Akiyama, T. Chem. Lett. 2014, 43, 137.
Electrophilic Fluorination • Fluorination Using Multiple Catalysts • Combination of Chiral Anion Phase-Transfer Catalysis and Enamine Catalysis Toste, F. D. J. Am. Chem. Soc. 2014, 136, 5225.
Electrophilic Fluorination • One-Pot and Tandem Processes • Asymmetric Synthesis of Fluorinated Flavanone Derivatives • Diastereo- and Enantioselective Tandem 1,4-Addition/Fluorination Transitionstate model for the oxa-Michael addition step. (Re face attack) Zhao, G. Chem.–Eur. J. 2009, 15, 13299. Ma, J.-A. Angew. Chem., Int. Ed. 2011, 50, 9442.
Nucleophilic Fluorination • Cooperative Catalysis in the Enantioselective Fluorination of Epoxides Doyle, A. G. J. Am. Chem. Soc. 2010, 132, 3268. Doyle, A. G. J. Am. Chem. Soc. 2011, 133, 16001.
Nucleophilic Fluorination • Cooperative Catalysis in the Enantioselective Fluorination of Aziridines Doyle, A. G. Tetrahedron2013, 69, 5702.
Nucleophilic Fluorination • Palladium-Catalyzed Asymmetric Synthesis of Allylic Fluorides Doyle, A. G. J. Am. Chem. Soc. 2010, 132, 17402. Doyle, A. G. J. Am. Chem. Soc. 2011, 133, 15902.
Summary and Outlook • There has been remarkable progress in the past decade toward catalytic asymmetric methods for the introduction of fluorine atom into small molecules. • Both transition metal catalysis and organocatalysis were applied as the strategies for the catalytic enantioselective fluorination. • Various types of products were obtained. • Reviews: • Toste, F. D. Chem. Rev. 2015, 115, 826. • Cahard, D. Chem. Rev. 2008, 108, PR1. • Cahard, D. Chem. Rev. 2004, 104, 6119.