Chemical Photocatalysis

Cover
Half Title
Also of interest
Chemical Photocatalysis
Copyright
Preface
Preface to the second edition
Contents
List of contributing authors
1. Early pioneers of organic photochemistry
	References
2. Photophysics of photocatalysts
	2.1 Setting the frame
	2.2 The experimentalist’s perspective
	2.3 The theoreticians’ perspective: A closer look
		2.3.1 Transition probabilities
		2.3.2 Orbitals
	References
3. Flavin photocatalysis
	3.1 Introduction
		3.1.1 General properties
	3.2 Early examples of flavin photocatalysis
	3.3 Flavin photocatalysis in synthesis application
	3.4 Flavin-related compounds in photocatalysis
	3.5 Isomerizations, cyclizations and cycloeliminations
	3.6 Photooxidations via singlet oxygen mechanism
	3.7 Conclusion
	References
4. Templated enantioselective photocatalysis
	4.1 Introduction
	4.2 Early studies. Paternò–Büchi cycloadditions of a chiral aromatic aldehyde and cyclic enamines
	4.3 Enantioselective Norrish–Yang cyclization reaction of prochiral imidazolidinones
	4.4 Enantioselective photochemical [4 + 4]-cycloadditions and electrocyclic [4π]-ring closure of 2-pyridones
	4.5 Enantioselective [6π]-photocyclization of acrylanilides
	4.6 Enantioselective Diels–Alder reaction of a photochemically generated ortho-quinodimethane
	4.7 Formal [3 + 2]-photocycloadditions of 2-substituted naphthoquinones
	4.8 Intramolecular [2 + 2]-photocycloadditions of substituted 5,6-dihydro-1H-pyridin-2-ones
	4.9 Enantioselective radical cyclizations
		4.9.1 Reductive radical cyclization reactions of 3-(ω-iodoalkylidene)-piperidin-2-ones
		4.9.2 Reductive radical cyclization of 3-(3-iodopropoxy)propenoic acid derivatives
		4.9.3 Radical cyclization reactions of 4-substituted quinolones
	4.10 [2 + 2]-photocycloaddition reactions of isoquinolones
	4.11 [2 + 2]-photocycloaddition reactions of substituted quinolones
		4.11.1 Intermolecular [2 + 2]-photocycloaddition reactions of quinolones
		4.11.2 Inter- and intramolecular [2 + 2]-photocycloadditions of 4-(2′-aminoethyl)quinolones
		4.11.3 Intramolecular [2 + 2]-photocycloadditions of 4-(ω-alkenyloxy)-quinol-2-ones
	4.12 Light-induced enantioselective catalysis
		4.12.1 Enantioselective type II photooygenations of 2-pyridones
		4.12.2 Enantioselective addition of α-amino radicals to 3-alkylidene indolin-2-ones
		4.12.3 Catalyzed enantioselective photo-induced electron transfer reactions
		4.12.4 Xanthone-catalyzed enantioselective [2 + 2]-photocycloadditions of quinolones
		4.12.5 Intermolecular enantioselective [2 + 2]-photocycloadditions of pyridones
		4.12.6 Enantioselective [2 + 2]-photocycloadditions using visible light
	4.13 Conclusion
	References
5. Photocatalysis with nucleic acids and peptides
	5.1 Introduction
	5.2 DNA-assisted enantioselective reactions
		5.2.1 Photocatalytically active DNA (PhotoDNAzymes)
		5.2.2 Benzophenone as photosensitizers for PhotoDNAzymes
	5.3 Small peptides as organocatalysts
		5.3.1 Development of peptides for photocatalytic addition to styrenes
	5.4 Conclusion
	References
6. Photocatalytic decarboxylations
	6.1 Introduction
	6.2 Decarboxylative reactions
		6.2.1 Reactions via sp3-hybridized radicals from alkyl carboxylic acids
			Protodecarboxylation
			Alkylation
			Vinylation
			Allylation
			Alkynylation
			Arylation
			C–Heteroatom bond formations
		6.2.2 Reactions via sp2-hybridized radicals
			6.2.2.1 From aromatic carboxylic acids
			6.2.2.2 From α-keto acids
				Alkylation
				Vinylation
				Alkynylation
				Arylation
				Amidation
			6.2.2.3 From α,β-unsaturated carboxylic acids
				Alkylation
				Sulfonylation
	6.3 Conclusion
	References
7. Photoredox catalyzed α-functionalization of amines – visible light mediated carbon-carbon and carbon-hetero bond forming reactions
	7.1 Introduction
	7.2 Aza-Henry reaction
	7.3 Addition of malonates
	7.4 Mannich reaction
	7.5 Allylation
	7.6 Cyanation of tertiary amines
	7.7 Alkynylation
	7.8 [3+2] cycloaddition reaction
	7.9 Acylation
	7.10 C-heteroatom (C–P, C–O, C–N) bond formation
	7.11 Conclusion
	References
8. Visible-light photoredox catalysis with [Ru(bpy)3]2+: General principles and the twentieth-century roots
	8.1 Introduction
	8.2 [Ru(bpy)3]2+ and its photoredox properties
	8.3 Application of [Ru(bpy)3]2+ as catalyst in the twentieth century
	8.4 Conclusions
	Abbreviations
	References
9. Homogeneous visible light mediated transition metal catalysis other than Ruthenium and Iridium
	9.1 Introduction
	9.2 Copper in visible light catalysis
	9.3 Chromium in visible light catalysis
	9.4 Iron in visible light catalysis
	9.5 Nickel in visible light catalysis
	9.6 Zirconium in visible light catalysis
	9.7 Molybdenum in visible light catalysis
	9.8 Cerium in visible light catalysis
	9.9 Rhenium and platinum in visible light catalysis
	9.10 Uranium in visible light catalysis
	9.11 Summary
	References
10. Coupling photoredox and biomimetic catalysis for the visible-light-driven oxygenation of organic compounds
	10.1 Introduction
	10.2 Combining photoredox catalysis with heme-type catalysts
	10.3 Combining photoredox catalysis with biomimetic non-heme iron catalysts
	10.4 Coupled photoredox catalysts based on copper
	10.5 Di- and trinuclear ruthenium dyads for oxygenation
	10.6 Biocatalytic oxygenation
	10.7 Summary
	References
11. Synergistic visible light photoredox catalysis
	11.1 Introduction
	11.2 Stabilized iminium ions
		11.2.1 Secondary amine catalyzed Mannich reactions
		11.2.2 Coinage metal catalyzed alkynylation reactions
		11.2.3 NHC catalyzed acylations
	11.3 Electrophilic carbon centered radicals
		11.3.1 Secondary amine catalyzed α-alkylation of aldehydes
		11.3.2 Palladium-catalyzed C-H arylation
		11.3.3 Copper-catalyzed trifluoromethylation of aryl boronic acids
		11.3.4 Gold-catalyzed intra- and intermolecular arylative transformationsof alkenes and alkynes
	11.4 Nucleophilic carbon centered radicals
		11.4.1 Carbonyl radical anion (ketyl radical) and related species
			11.4.1.1 Reductive cyclization
			11.4.1.2 Intermolecular transformations involving ketyl radical species
		11.4.2 α-Amino alkyl radicals
		11.4.3 β-Enaminyl radicals
		11.4.4 Alkyl radicals in Ni/photoredox dual catalytic cross coupling reactions
	11.5 Conclusions and Future Outlook
	References
12. Excited radical anions and excited anions in visible light photoredox catalysis
	12.1 Introduction
	12.2 Radical anions as visible light absorbing photosensitizers
		12.2.1 Perylene diimide radical anion
		12.2.2 Rhodamine 6G (Rh-6G) radical anion
		12.2.3 9,10-Dicyanoanthracene (DCA) radical anion
		12.2.4 Anthraquinone radical and semiquinone anions
	12.3 Excited state anions in visible light photoredox catalysis
	12.4 The ground state PAH’s radical anions in visible light photoredox catalysis
	12.5 Conclusion
	References
13. Metal complexes for photohydrogenation and hydrogen evolution
	13.1 Analysis of construction components of artificial photocatalytic sy
		13.1.1 Chromophore
		13.1.2 Electron relay
		13.1.3 Redox equivalents
		13.1.4 Reduction catalysts
		13.1.5 Intramolecular hydrogen evolving photocatalysts
		13.1.6 Oxidation catalysts
		13.1.7 Intramolecular oxidation catalysts
		13.1.8 Comparison of inter- and intramolecular photocatalysis
	13.2 Intramolecular photocatalysts for hydrogen production and hydrogenation
		13.2.1 Hydrogen production
		13.2.2 Photohydrogenation
		13.2.3 Photophysics
		13.2.4 Ru(tpphz)Pd-type catalysts as photochemical molecular devices (PMD)
	13.3 Conclusion
	References
14. Heterogeneous semiconductor photocatalysis
	14.1 Inorganic semiconductors
		14.1.1 General features of a photocatalyst
			14.1.1.1 Band structure and band gap
			14.1.1.2 The fermi level and charge separation
		14.1.2 How to tune a photocatalyst
			14.1.2.1 Doping and co-catalysts
			14.1.2.2 Particle size effect
		14.1.3 Selected examples of photocatalysts and their application to organic synthesis
			14.1.3.1 TiO2 – an UV active photocatalyst
			14.1.3.2 Selected examples of visible light active photocatalysts
	14.2 Organic semiconductors
		14.2.1 Basic properties of organic semiconductors
			14.2.1.1 Band structure and band gap
			14.2.1.2 Photoinduced electron transfer – exciton generation and dissociation
		14.2.2 Application of conjugated polymers in photocatalysis
			14.2.2.1 Linear conjugated polymers
			14.2.2.2 Conjugated polymers with layered structure
	References
15. Polyoxometalates in photocatalysis
	15.1 Introduction
		15.1.1 Polyoxometalates – molecular metal oxide clusters
		15.1.2 Concepts in polyoxometalate photochemistry
		15.1.3 The basics of POM photochemistry
		15.1.4 Traditional photooxidation of organic substrates
	15.2 Recent developments in POM photochemistry
		15.2.1 Water oxidation by Ru- and Co-polyoxometalates
		15.2.2 Polyoxoniobate water oxidation
		15.2.3 Water oxidation by Dawson anions in ionic liquids
		15.2.4 Photoreductive CO2-activation
		15.2.5 Photoreductive H2 generation
	15.3 Optimizing photocatalytic performance of polyoxometalates
		15.3.1 Structurally adaptive systems
		15.3.2 Optimized photoactivity by metal substitution
		15.3.3 Inspiration from the solid-state world
	15.4 Conclusion
	References
16. Description of excited states in photochemistry with theoretical methods
	16.1 Introduction
	16.2 The concept of PESs
	16.3 Computational methods for excited states
		16.3.1 QM methods
			16.3.1.1 Time-dependent coupled cluster response
			16.3.1.2 Time-dependent density functional theory
		16.3.2 Solvent description via the QM/MM approach
			16.3.2.1 MM methods
			16.3.2.2 QM/MM coupling
	16.4 Procedure
	16.5 Examples
	16.6 Roseoflavin
	16.7 Benzophenone in dinucleotides
	16.8 Photoinduced ring closure in DAE
	16.9 Conclusion
	References
17. Transient absorption with a streak camera
	17.1 Introduction
	17.2 Experimental setup
	17.3 Data analysis
		17.3.1 SVD and rank analysis
		17.3.2 Global lifetime analysis
		17.3.3 Eliminating invalid data
		17.3.4 Maximum entropy analysis
	17.4 Performance
		17.4.1 RFTA alone
		17.4.2 Photooxidation of MBA with RFTA
	17.5 Discussion
	17.6 Conclusion
	References
18. Time resolved spectroscopy in photocatalysis
	18.1 UV/Vis absorption spectroscopy: More than just ε!
	18.2 Time-Resolved spectroscopic methods from fs to µs to elucidate photocatalytic processes
		18.2.1 Transient absorption spectroscopy: Signals, time scales, and data processing
		18.2.2 Spectroscopy on the fs to ps time scale
		18.2.3 Spectroscopy on the ns to μs time scale
		18.2.4 Rate models and the determination of the species associated spectra of the intermediate states
	18.3 Diffusion limited reactions
		18.3.1 Diffusion limited excited state quenching with time dependent reaction rate
		18.3.2 Application of the diffusion fit function to experimental data
	18.4 Costs of photocatalysis: The reaction quantum yield
		18.4.1 Requirements for an accurate definition of the quantum yield
		18.4.2 Determination of the quantity of excited molecules in transient absorption measurements
		18.4.3 Example of the spectroscopic determination of reaction quantum yields: Flavin photocatalysis
	18.5 From light absorption to chemistry: Sensitizing mechanisms in homogeneous photocatalysis
		18.5.1 Sensitization by excitation energy transfer
		18.5.2 Photoredox catalysis: Requirements on catalyst and substrate
	18.6 Epilogue
	References
Index