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SOMO catalysis and. Photoredox Organocatalysis:. Work of David W.C. MacMillan. Dominic Fiset 05/10/11. About Me. RIP 1972-1995. About Me. Outline. Introduction David W.C. MacMillan First Developments in Organocatalysis Aminocatalysis : Activation modes
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SOMO catalysis and Photoredox Organocatalysis: Work of David W.C. MacMillan Dominic Fiset 05/10/11
About Me RIP 1972-1995
Outline • Introduction • David W.C. MacMillan • First Developments in Organocatalysis • Aminocatalysis: Activation modes • Singly-Occupied Molecular Orbital catalysis • Previously Reported Radical Alkylation • Mechanistic Considerations • Scope and Limitations • PhotoredoxOrganocatalysis • Merging SOMO Catalysis with Photoredox Chemistry • Mechanistic Considerations • Synthetic Utility
Pr. David W.C. MacMillan • Biography • Born in Bellshill, Scotland, in 1968 • 1987-91: Undergrad with Dr. Ernie Colvin at the University of Glasgow - 1991- 96: PhD. with Professor Larry E. Overman - 1996-98: Postdoctoral research fellow with Professor David E. Evans • 1998-2000: Independent Research at University of California, Berkeley • 2000-2006: Professor of Chemistry at the California Institute of Technology • 2006-...: Professor of Chemistry at Princeton University • 2o10-…: Editor-in-Chief of Chemical Science published by RSC • Research Interests • Organocatalysis • Mechanist investigation • SOMO catalysis • Merging photoredox catalysis and organocatalysis • Total synthesis of complex natural products • h http://www.princeton.edu/chemistry/macmillan/index.xml
Birth of Organocatalysis Hajos-Parrisch-Eder-Sauer-Wiechert reaction (1970s) • (a) Cheong, P. H.-Y.; Legault, C. Y.; Um, J. M.; Çelebi-Ölçüm, N.; Houk, K. N. Chem. Rev. 2011, 111, 5042 • (b) Hajos, A. G.; Parrish, D. R. J. Org. Chem. 1974, 39, 1612 • (c) Eder, U.; Sauer, G.; Wiechert, R. Angew. Chem., Int. Ed. Engl.1971, 10, 496.
Advent of MordernOrganocatalysis: Asymmetric Aminocatalysis Enamine catalysis: Aldol reaction Iminium catalysis: Diels-Alder reaction • (a) List, B.; Lerner, R. A.; Barbas, C. F., III J. Am. Chem. Soc. 2000, 122, 2395. • (b) List, B. Synlett 2001, 1675 • 2. Ahrendt, K. A.; Borths, C. J.; MacMillan, D. W. C. J. Am. Chem. Soc. 2000, 122, 4243
Asymmetric aminocatalysis: Activation Modes • (a) Grondal, C.; Jeanty, M.; Enders, D. Nat .Chem. 2010, 2, 167. • (b) MacMillan, D. W. C. Nature 2008, 455, 304
The Holy Grail Reaction Pioneering work by List and Córdeva Catalytic asymmetric intermolecular α-alkylation of aldehydes • (a) Vignola, N.; List, B. J. Am. Chem. Soc. 2003, 126, 450 • (b) Ibrahem, I.; Córdova, A. Angew. Chem. Int. Ed. 2006, 45, 1952 • 2. Melchiorre, P. Angew. Chem. Int. Ed. 2009, 48, 1360
The Holy Grail Reaction: A New Activation Mode Asymmetric intermolecular α-alkylation of aldehyde Is there a solution ? • MacMillan, D.W.C. Lecture 4: New acctivation mode (SET pathways), available online at http://www.princeton.edu/chemistry/macmillan/research/MacMillan%20Lecture%204.pdf
A New Activation Mode:Singly-Occupied Molecular Orbital Catalysis Aminocatalysis: A new activation mode 1 SOMO catalysis: A new synthetic paradigm • Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582
Enamine oxidation: Racemic SOMO catalysis Stereoselective addition of radicals to chiral enamines: work of Shubert Cation radicals of enamines: work of Murakami and coworkers Construction of quaternary center: work of Cossy • Renaud, P.; Schubert, S. Synlett 1990, 624 • Narasaka, K.; Okauchi, T.; Tanaka, K.; Murakami, M. Chem. Lett. 1992, 21, 2099 • (a) Cossy, J.; Bouzide, A. J. Chem. Soc., Chem. Commun. 1993, 1218(b) Cossy, J.; Bouzide, A.; Leblanc, C. Synlett 1993, 202
SOMO catalysis: Work of D.W.C. MacMillan • Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582
Intermolecular Allylation of Aldehydes • Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582
Potential for a Broad Scope • Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582
SOMO Catalysis: Evidence for Radical Pathway • (a) Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582 • (b) Le Tadic-Biadatti, M.-H.; Newcomb, M. Journal of the Chemical Society, Perkin Transactions 2 1996, 1467
Organo-SOMO Catalysis • (a) Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582 • (b) Le Tadic-Biadatti, M.-H.; Newcomb, M. Journal of the Chemical Society, Perkin Transactions 2 1996, 1467
Chemoselective Oxidation • (a) Devery, J. J.; Conrad, J. C.; MacMillan, D. W. C.; Flowers, R. A. Angew. Chem. Int. Ed. 2010, 49, 6106 • (b) Beel, R.; Kobialka, S.; Schmidt, M. L.; Engeser, M. Chem. Commun. 2011, 47, 3293 • (c) Um, J. M.; Gutierrez, O.; Schoenebeck, F.; Houk, K. N.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 6001
Origin of the Enantioselectivity Steric Control Approach • Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582
Catalytic Turnovers • Water Plays a Key Role • Concentration of catalyst is maintained by H2O (below 2.00 eq, the catalyst is • deactivated) • Effect on the phase-transfer process that controls the homogenous concentration • of the oxidant (CAN) • - Bench-grade DME contains sufficient water to achieve optimal results • (a) Beeson, T. D.; Mastracchio, A.; Hong, J.-B.; Ashton, K.; MacMillan, D. W. C. Science 2007, 316, 582 • (b) Devery, J. J.; Conrad, J. C.; MacMillan, D. W. C.; Flowers, R. A. Angew. Chem. Int. Ed. 2010, 49, 6106
SOMO catalysis: Work of M. P. Sibi • (a) Sibi, M. P.; Hasegawa, M. J. Am. Chem. Soc. 2007, 129, 4124 • (b) Van Humbeck, J. F.; Simonovich, S. P.; Knowles, R. R.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10012
Work of M. P. Sibi: Revisited by MacMillan • (a) Sibi, M. P.; Hasegawa, M. J. Am. Chem. Soc. 2007, 129, 4124 • (b) Van Humbeck, J. F.; Simonovich, S. P.; Knowles, R. R.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10012
Work of M. P. Sibi: Revisited by MacMillan Conditions Recently Re-Optimized by MacMillan: ‘’Synergistic catalysis’’ • (a) Van Humbeck, J. F.; Simonovich, S. P.; Knowles, R. R.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10012 • (b) Simonovich, S. P.; Van Humbeck, J. F.; MacMillan, D. W. C. Chemical Science 2011, ASAP, DOI: 10.1039/C1SC00556A
a-Enolation of Aldehydes • Jang, H. Y.; Hong, J. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2007, 129, 7004
a-Vinylation of Aldehydes: Mechanism • Kim, H.; MacMillan, D. W. C. J. Am. Chem. Soc. 2008130, 39
a-Vinylation of Aldehydes: Scope Synthetic Application • Kim, H.; MacMillan, D. W. C. J. Am. Chem. Soc. 2008130, 39
Carbo-oxidation of Styrenes • Graham, T. H.; Jones, C. M.; Jui, N. T.; MacMillan, D. W. C. J. Am. Chem. Soc. 2008, 130, 16494.
Carbo-oxidation of Styrenes Rapid Acess to Heterocyclic Rings Homobenzylation of aldehyde • Graham, T. H.; Jones, C. M.; Jui, N. T.; MacMillan, D. W. C. J. Am. Chem. Soc. 2008, 130, 16494.
Organo-SOMO Cascade Cycloadditions • Jui, N. T.; Lee, E. C. Y.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10015
Organo-SOMO Cascade Cycloadditions • Jui, N. T.; Lee, E. C. Y.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10015
Organo-SOMO Cascade Cycloadditions • Jui, N. T.; Lee, E. C. Y.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 10015
Intramolecular a-Allylation Catalyst –controlled stereoselective piperidine formation • Pham, P. V.; Ashton, K.; MacMillan, D. W. C. Chemical Science 2011, 2, 1470
Intramolecular a-Arylation of Aldehydes • (a) Nicolaou, K. C.; Reingruber, R. d.; Sarlah, D.; Bräse, S. J. Am. Chem. Soc. 2009, 131, 6640 • (b) Conrad, J. C.; Kong, J.; Laforteza, B. N.; MacMillan, D. W. C. J. Am. Chem. Soc. 2009, 131, 11640 • (c) Um, J. M.; Gutierrez, O.; Schoenebeck, F.; Houk, K. N.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 6001
a-Chlorination and Terminal Epoxide Formation • Amatore, M.; Beeson, T. D.; Brown, S. P.; MacMillan, D. W. C. Angew. Chem. Int. Ed. 2009, 48, 5121
a-Chlorination and Terminal Epoxide Formation • Amatore, M.; Beeson, T. D.; Brown, S. P.; MacMillan, D. W. C. Angew. Chem. Int. Ed. 2009, 48, 5121
a-Chlorination and Terminal Epoxide Formation • Amatore, M.; Beeson, T. D.; Brown, S. P.; MacMillan, D. W. C. Angew. Chem. Int. Ed. 2009, 48, 5121
a-Allylation of Ketones • (a) Northrup, A. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 2458 • (b) Mastracchio, A.; Warkentin, A. A.; Walji, A. M.; MacMillan, D. W. C. Proceedings of the National Academy of Sciences 2010, 107, 20648
Polyene Cyclization • (a) MacMillan, D.W.C. Lecture 4: New acctivation mode (SET pathways), available online at http://www.princeton.edu/chemistry/macmillan/research/MacMillan%20Lecture%204.pdf • (b) Rendler, S.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 5027
Polyene Cyclization: Mechanism • (a) MacMillan, D.W.C. Lecture 4: New acctivation mode (SET pathways), available online at http://www.princeton.edu/chemistry/macmillan/research/MacMillan%20Lecture%204.pdf • (b) Rendler, S.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 5027
Polyene Cyclization: Scope 1. Rendler, S.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 5027
Merging SOMO and Photoredox catalysis Reversing the role of the aminocatalyst 1. Rendler, S.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 5027
Light Photoredox Catalysis 1 Narayanam, J. M. R.; Stephenson, C. R. J. Chem. Soc. Rev. 2011, 40, 102
Light Photoredox Catalysis 1 Juris, A.; Balzani, V.; Barigelletti, F.; Campagna, S.; Belser, P.; von Zelewsky, A. Coord. Chem. Rev. 1988, 84, 85
Merging SOMO and Photoredox catalysis 1 Nicewicz, D. A.; MacMillan, D. W. C. Science 2008, 322, 77
Merging SOMO and Photoredox catalysis 1 Nicewicz, D. A.; MacMillan, D. W. C. Science 2008, 322, 77
Photoredox organocatalysis: Mechanism 1 Nicewicz, D. A.; MacMillan, D. W. C. Science 2008, 322, 77
PhotoredoxOrganocatalysis: Control Experiments • Rigorous exclusion of light: • No alkylation product • Removal of Ru(bpy)32+: • <10% of alkylation product over an extended timeframe (24h) • Ru(bpy)32+ can be replaced by high-energy UV irradiation source • Reaction efficiency over 80% • Fluorescent quenching experiments with Ru(bpy)32+* • Ru(bpy)32+* excited state behaves as an oxidant in the photoredox cycle 1 Nicewicz, D. A.; MacMillan, D. W. C. Science 2008, 322, 77
Enantioselective a-Trifluoromethylation 1 Nagib, D. A.; Scott, M. E.; MacMillan, D. W. C. J. Am. Chem. Soc. 2009, 131, 10875
Enantioselective a-Trifluoromethylation 1 Nagib, D. A.; Scott, M. E.; MacMillan, D. W. C. J. Am. Chem. Soc. 2009, 131, 10875
Enantioselective a-Benzylation 1 Shih, H.-W.; Vander Wal, M. N.; Grange, R. L.; MacMillan, D. W. C. J. Am. Chem. Soc. 2010, 132, 13600