Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• reactions with nucleophiles like malonates, cyanides, and phosphites. The study further revealed that the radicals generated from these processes can be successfully utilized in dual catalysis with copper, yielding a variety of alkynylated products (Figure 11) [65]. Compound 46 has been shown to exhibit

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• , Gutierrez and Molander reported the coupling 4-alkyl-1,4-dihydropyridines 31 with heterobicyclic alkenes 30 under photoredox/Ni dual catalysis (Scheme 6) [39]. In contrast to other photoredox-mediated transformations, the authors utilized the inexpensive organic photosensitizer 4-CzIPN (Scheme 6 and Scheme

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• ON/OFF manner [99]. To test for dual catalysis (Figure 22b), State-I was reacted at 50 °C with 1.0 equiv of catalyst 99 (with respect to rotor) and 10.0 equiv (with respect to rotor) of substrates 75, 86, 95, and 102 in CD2Cl2/CD3CN 5:1 for 2 h. Analysis demonstrated that 30% of product 101 but no

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• additions of these heteroarenes with crotonaldehyde yielded the adducts in moderate to good enantioselectivity under dual catalysis of chiral amines (Scheme 5) [69]. Conclusion The asymmetric aza-Michael reaction being a useful synthetic strategy for constructing C–N bonds to make a variety of nitrogen

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• often requires relatively high catalyst loadings, directing groups, high reaction temperatures (100–160 °C), stoichiometric additives, or oxidants such as peroxide or silver salts that can be undesirable for large scale synthesis. Recently, photoredox dual catalysis has witnessed significant

• combined with radical species [41][42][43], a wide variety of reactions have been discovered. Within a remarkable renaissance of photoredox dual catalysis, nickel/photoredox catalysis has recently been identified as a viable C‒H functionalization tool under milder reaction conditions [40][44][45][46][47

• –H functionalization is a valuable method for synthesizing useful organic compounds from simple alkane starting materials [51][69][70]. Recently, Lu and co-workers reported an enantioselective benzylic C–H arylation method for synthesizing 1,1-diarylalkanes 26 via a photoredox and nickel dual

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• stereoselective one-pot procedure for the synthesis of five-membered annulated coumarins 28 was described by the group of Enders [40]. Using dual catalysis, with a cinchona primary amine derivative 22 and silver carbonate, a series of functionalized coumarin derivatives 28 were obtained in good yields (up to 91

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• [76]. Cases of C–P bond construction employing photoredox [77][78] or photoredox/nickel dual catalysis [79] have been identified in the field of photochemistry. However, here we introduce the methods initiated by EDA complexes for C–P bond construction. In 2018, Lakhdar and colleagues [44] reported a

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• SelfSORT-II, in which the 46 kHz-nanorotor acts as copper(I)-based catalyst in a click reaction. ON/OFF control of a networked catalytic catch–release system. A multicomponent information system for the reversible reconfiguration of switchable dual catalysis. a) The chemically fueled cascaded ion

• + + [Cu2(40)2]2+ + 2 × [Cu(42)]+ (= SelfSORT-II). With SelfSORT-I containing the heterocycle 42, a known organocatalyst, and SelfSORT-II holding the potential click catalyst [Cu(42)]+, it was speculated that both networked states could be catalytically active thus allowing the ON/OFF regulation of a dual

• catalysis. For the evaluation of this property, the state SelfSORT-I was heated at 50 °C with 1.0 equiv of the catalyst 42 (with respect to the rotor), and 10.0 equiv (with respect to the rotor) of substrates 43, 44, 46, and 47 in CD2Cl2/CD3CN 5:1. After heating the mixture for 2 h, 30% of the product 45

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• catalytic system is extremely appealing. In that perspective, the scope of this review aims to present innovative reactions combining C–H activation and visible-light induced photocatalysis. Keywords: C–H activation; C–H functionalization; dual catalysis; photoredox catalysis; radical chemistry

• catalysis is undoubtedly the most thoroughly investigated approach and consequently, the most widely described in the literature [66][67]. The interest of the scientific community towards this dual catalysis and further developments were pioneered by MacMillan [68] and Molander [69]. The general mechanism

• general strategy, in 2014, Rueping and co-workers reported the pioneering contribution concerning the synthesis of indoles via an intramolecular C–H/C–H oxidative coupling of N-arylenamines under air atmosphere. This procedure was based on dual catalysis involving a double C–H activation system and

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

• Quentin Lefebvre,
• Christophe Salomé and
• Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

• thus be rapidly accessed, identifying privileged or challenging scaffolds and paving the way for further exploration. Keywords: benchtop analytics; fragment-based library; heterocyclic sp2–sp3 fragments; N-arylation; photoredox-nickel dual catalysis; Introduction Heterocyclic sp2–sp3 fragments are

• initiated a high-throughput program of fragment-based library generation and after shortcomings using more classical cross-coupling conditions, we turned our attention to the photoredox-nickel dual-catalysis strategy recently reported by MacMillan and Buchwald [10]. The reported conditions use lower

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• involving Ni complexes as catalysts, MacMillan and co-workers showed that Ni metallocatalysis can be successfully combined with photocatalysis (with Ir complexes) in a dual catalysis platform, which enables sp3–sp3 and sp2–sp3 bond formations [35]. In this context, metalloporphyrins emerge as an interesting

• platform for dual catalysis due to their ability to promote both metallocatalysis and photocatalysis in a one-pot system [36][37][38][39]. Martin and co-workers carried out the C–O bond cleavage of alcohols using a cobalt porphyrin under visible light irradiation and a carbon monoxide atmosphere (Scheme 11

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• of photoredox catalysts for the functionalization of inert bonds in the domain of synthetic organic chemistry. Keywords: dual catalysis; light; ortho and para C–H bond functionalization; photoredox catalysis; Introduction Over a short period of time, direct C–H bond functionalizations by photoredox

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

Copper-catalyzed asymmetric sp³ C–H arylation of tetrahydroisoquinoline mediated by a visible light photoredox catalyst

• Pierre Querard,
• Inna Perepichka,
• Eli Zysman-Colman and
• Chao-Jun Li

Beilstein J. Org. Chem. 2016, 12, 2636–2643, doi:10.3762/bjoc.12.260

• , St Andrews, Fife, KY16 9ST, UK 10.3762/bjoc.12.260 Abstract This report describes a highly enantioselective oxidative sp3 C–H arylation of N-aryltetrahydroisoquinolines (THIQs) through a dual catalysis platform. The combination of the photoredox catalyst, [Ir(ppy)2(dtbbpy)]PF6, and chiral copper

Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions

• Rajeev S. Menon,
• Akkattu T. Biju and
• Vijay Nair

Beilstein J. Org. Chem. 2016, 12, 444–461, doi:10.3762/bjoc.12.47

• catalyst rapidly shuttles the intermediate δ-keto aldehyde 61 to the final product preventing the erosion of enantioselectivity [54]. This cascade reaction constitutes a fine example of symbiotic dual-catalysis wherein both catalysts perform better together in a one-pot reaction than they do independently

A concise enantioselective synthesis of the guaiane sesquiterpene (−)-oxyphyllol

• Martin Zahel and
• Peter Metz

Beilstein J. Org. Chem. 2013, 9, 2028–2032, doi:10.3762/bjoc.9.239

• Recently, we developed an efficient access to the anticancer guaiane (−)-englerin A (5) starting from (−)-photocitral A (6), which in turn can be prepared in only 2 steps from commercially available (−)-isopulegol through dual catalysis [6]. Due to the structural similarity of the hydroazulene core in

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• processes, merging it with another type of catalysis has become a recent development in the field of visible light photocatalysis. One direct benefit of this dual catalysis approach is to allow expansion of the types of nucleophiles capable of adding to the iminium ions generated under photoredox conditions

• work much better using the former catalyst. Other types of pronucleophiles such as malonates are also effective in the Mannich reaction. The Rueping group extended the concept of dual catalysis by merging visible light photocatalysis with a metal-catalyzed process (Scheme 10) [77]. To make this

• the photogenically-produced iminium ion 27a, thus achieving the formation of Csp3–Csp bonds. Rovis and coworkers recently developed another mode of dual catalysis involving visible light photocatalysis with chiral N-heterocyclic carbene catalysis, which allows catalytic asymmetric α-acylation of N

Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

• Yannick Borguet,
• Xavier Sauvage,
• Guillermo Zaragoza,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2010, 6, 1167–1173, doi:10.3762/bjoc.6.133

• inhibited the cyclization as evidenced by GC analysis, which revealed a complete conversion of substrate 4 into intermediate 5, but did not show any sign of product 6 formation (Table 2, entry 3). On the other hand, it was possible to accomplish the dual catalysis at 160 °C with only 1 mol % of catalyst