Dual Catalysis Research Articles

Ni-catalyzed regioselective C–C bond formation of 1,1-disubstituted allenes with aldehydes

A regio- and stereoselective coupling process between allenes and aldehydes has been developed to obtain a linear homoallylic secondary alcohols by photoredox/Ni dual catalysis.

Nickel/photoredox dual-catalyzed reductive cross-coupling of aryl halides and aldehydes

A photoredox-assisted nickel-catalyzed reductive coupling of aryl halides and aldehydes to afford silyl-protected alcohols is reported. Key to success of this strategy is to identify α-silylamines as efficient organic reductants.

Synthesis of a Series of 4H-Pyran Derivatives with Multicomponent Reaction in DBSA/H2O Microemulsion System

A series of 4H-pyran derivatives were synthesized through a three-component condensation reaction in a pot using aromatic aldehyde, cyclohexanedione, and malononitrile in the dodecyl benzenesulfonic acid/H2O microemulsion system. This protocol is attractive because dodecyl benzenesulfonic acid microemulsion is superior for organic reaction due to its dual catalysis. On the one hand, dodecyl benzenesulfonic acid acts as a Brønsted acid to catalyze the reaction; on the other hand, it can form a microemulsion as surfactant to enlarge the boundary area and entrap water produced during esterification reaction. In addition, the reaction process is simple, with high liaison formation efficiency, good yields, and environmentally harmless reaction conditions. The dodecyl benzenesulfonic acid/H2O microemulsion system was equally effective when used in consecutive reactions.

Direct synthesis of dialkyl ketones from deoxygenative cross-coupling of carboxylic acids and alcohols

A direct deoxygenative cross-coupling between carboxylic acids and alcohols for dialkyl ketone synthesis via photoredox/nickel dual catalysis was developed. This protocol provides a powerful platform to construct a range of diverse ketone scaffolds.

Photoinduced C–H arylation of 1,3-azoles via copper/photoredox dual catalysis

The photo-induced azole C–H arylation was realized with a dual-catalytic copper-based system. Exceedingly mild reaction conditions at ambient temperature and visible light irradiation enabled a broad scope with high functional group tolerance.

Alkenylation of unactivated alkanes: synthesis of Z-alkenes via dual Co-TBADT catalysis.

Hydroalkylation of terminal alkynes via C-H activation is the most atom-economical and straightforward method for synthesizing alkenes. They remain confined to using C(sp2)-H or activated C(sp3)-H bonds. A chelating group enabled the alkenylation of C(sp3)-H bonds, resulting in E alkenes. Protocols by which alkenylation of unactivated C(sp3)-H bonds occurs without a chelating group via metal-hydride or radical pathways remain unknown. Our cobalt-HAT catalysis achieves the desired Z alkene with excellent regio- and diastereoselectivity via C-H activation.

Photoredox chromium and cobalt dual catalysis for carbonyl allylation with butadiene via allyl radical intermediates

The allylation of aldehydes with dienes was achieved using cobalt and chromium catalysts through a metal-hydride hydrogen atom transfer (MHAT) pathway. The novel reaction resulted in the formation of various homo-allyl alcohols with excellent diastereoselectivity.

Copper/ruthenium relay catalysis enables 1,6-double chiral inductions with stereodivergence.

The dual catalysis strategy is an efficient and powerful tool to fulfill the stereodivergent synthesis of stereoisomeric products from the same set of starting materials. Great attention has been given to the construction of chiral compounds with two contiguous stereocenters. However, the synthesis of two remote noncontiguous stereocenters is more challenging and is less developed, despite the high demand for synthetic tactics. We herein developed an unprecedented example of the stereodivergent preparation of synthetically useful and biologically important chiral ζ-hydroxy amino ester derivatives containing remote 1,6-noncontiguous stereocenters and a unique β,γ-unsaturation moiety. This cascade dehydrogenation/1,6-Michael addition/hydrogenation protocol between readily-available ketoimine esters and racemic branched dienyl carbinols was rationally realized with bimetallic copper/ruthenium relay catalysis. The key features of the process were atom economy, step economy, and redox-neutrality. All four stereoisomers of chiral ζ-hydroxy amino ester derivatives were easily achieved by the orthogonal permutations of a chiral copper catalyst and chiral ruthenium catalyst. Importantly, a much more challenging stereodivergent synthesis of all eight stereoisomers of chiral peptide products containing three remote stereocenters was accomplished with excellent results through the cooperation of two chiral catalyst pairs and substrate enantiomers.

Incorporation of Ir(C^N)2(N^N)-NiCl2 in a (N^N)-covalent organic framework for transcendent dual catalysis in photochemical cross-coupling synthesis

The incorporation of Ir(C^N)2(N^N)-NiCl2 in quinoline-based (N^N)-covalent organic framework exhibits remarkable photocatalytic activities in cross-coupling synthesis.

Visible light driven photoredox/nickel-catalyzed stereoselective synthesis of Z- or E-vinyl thioethers from thiosilane and terminal alkynes.

A new method for the synthesis of anti-Markovnikov Z- or E-vinyl thioethers from thiosilane and terminal alkynes under visible-light-induced photoredox/nickel dual catalysis conditions is described. With a judicious choice of a simple nickel catalyst and a ligand, this strategy enables efficient and divergent access to both Z- or E-vinyl thioethers from the same set of simple starting materials. Notably, the approach is free of odorous thiol and has excellent compatibility with functional groups and substrate scope.

Recent advancements in Ni/photoredox dual catalysis for Csp3–Csp3 cross-coupling reactions

This minireview highlights recent advancements in the past five years (since 2019) in Ni/photoredox dual catalysis for Csp3–Csp3 cross-coupling reactions.

Nickel metallaphotoredox-catalyzed C–O bond activation/Csp2–Csp3 coupling enabled by phosphine

A novel and general nickel/photoredox dual catalysis platform for benzyl alcohol C–O bond activation/Csp2–Csp3 cross coupling of benzothiazolyl bromide and free alcohol, enabled by the catalytic generation of an alkyl radical, is reported.

Trifluoromethylthiolation of Arenes Using Lewis Acid and Lewis Base Dual Catalysis.

Incorporation of the highly lipophilic trifluoromethanesulfenyl group into bioactive molecules facilitates transport through lipid membranes, and thus, CF3S-containing compounds are important for drug discovery. Although reagents and procedures have been reported for arene trifluoromethylthiolation, methods are still required that are applicable to a diverse substrate scope and can be performed under mild conditions. Here, we describe a rapid and efficient approach for the trifluoromethylthiolation of arenes by catalytic activation of N-trifluoromethylthiosaccharin using a combination of iron(III) chloride and diphenyl selenide. This dual catalytic process allowed regioselective functionalization of a wide range of arenes and N-heterocycles under mild conditions and was used for the trifluoromethylthiolation of bioactive compounds such as tyrosine and estradiol.

Dual Photoredox Catalysis with Vanadium Complexes in Low Oxidation State: Diastereoselective Pinacol Coupling

AbstractDual photoredox catalysis is modifying the approach to sustainable metal catalysis based on metals in low oxidation state, as the use of stoichiometric metal as reductants are avoided. In this study, we showcase the potential use of vanadium in a dual photoredox process, allowing us to effectively control the formation of V(II) and its corresponding chemical reactions. A diastereoselective pinacol coupling with aromatic aldehydes is described. The process shows broad scope, and interestingly, unprotected salicylic aldehydes are compatible with the reaction protocol. Additionally, among all the ligands investigated we found that inexpensive bipyridines control the diastereoselection of the reaction favoring the d,l chiral compound (dr>20:1 for most of the aldehydes investigated). To promote the reaction and avoid an unproductive and not stereoselective radical coupling of the generated ketyl radical, the use of [DMQA]+, a stable organic dye, was found crucial. Furthermore, this dye possesses the remarkable capability of efficiently capturing light in the red segment of the visible spectrum, effectively raising efficiency of the protocol. The utilization of red light carries notable advantages in terms of penetration and safety, making it particularly significant. Moreover, careful photophysical investigations were able to give indications about the mechanism of the reaction.

Inside Back Cover: Dual Catalysis of Gold Nanoclusters: Photocatalytic Cross‐Dehydrogenative Coupling by Cooperation of Superatomic Core and Molecularly Modified Staples (Angew. Chem. Int. Ed. 2/2024)

Inside Back Cover: Dual Catalysis of Gold Nanoclusters: Photocatalytic Cross‐Dehydrogenative Coupling by Cooperation of Superatomic Core and Molecularly Modified Staples (Angew. Chem. Int. Ed. 2/2024)

Innenrücktitelbild: Dual Catalysis of Gold Nanoclusters: Photocatalytic Cross‐Dehydrogenative Coupling by Cooperation of Superatomic Core and Molecularly Modified Staples (Angew. Chem. 2/2024)

Innenrücktitelbild: Dual Catalysis of Gold Nanoclusters: Photocatalytic Cross‐Dehydrogenative Coupling by Cooperation of Superatomic Core and Molecularly Modified Staples (Angew. Chem. 2/2024)

Amidative β-Scission of Alcohols Enabled by Dual Catalysis of Photoredox Proton-Coupled Electron Transfer and Inner-Sphere Ni-Nitrenoid Transfer.

The photoredox/Ni dual catalysis is an appealing strategy to enable unconventional C-heteroatom bond formation. While significant advances have been achieved using this system, intermolecular C(sp3)-N bond formation has been relatively underdeveloped due to the difficulty in C(sp3)-N reductive elimination. Herein, we present a new mechanistic approach that utilizes dioxazolones as the Ni(II)-nitrenoid precursor to capture carbon-centered radicals by merging proton-coupled electron transfer (PCET) with nickel catalysis, thus forming synthetically versatile N-alkyl amides using alcohols. Based on mechanistic investigations, the involvement of (κ2-N,O)Ni(II)-nitrenoid species was proposed to capture photoredox PCET-induced alkyl radicals, thereby playing a pivotal role to enable the C(sp3)-N bond formation.

Visible-Light-Driven Regioselective Decarboxylative Acylation of N-Methyl-3-phenylquinoxalin-2(1H)-one by Dual Palladium-Photoredox Catalysis Through C-H Activation.

We report herein an efficient visible-light-promoted approach for the regioselective decarboxylative C-H acylation of N-methyl-3-phenylquinoxalin-2(1H)-ones using α-oxo-2-phenylacetic acids via dual palladium-photoredox catalysis. The reactions were carried out at room temperature in the presence of 24 W blue LEDs. The established protocol tolerated a wide range of functional groups and enabled the synthesis of several acylated N-methyl-3-phenylquinoxalin-2(1H)-ones in good to excellent yields. The proposed mechanism for this transformation was supported by control experiments.

Redox-Neutral Cyclization of 2-Isocyanobiaryls through Photoredox/PPh3 Dual Catalysis.

The photoredox/PPh3-mediated cyclization of 2-isocyanobiaryls has been developed. A substantial range of functional-group-rich phenanthridine derivatives were synthesized at room temperature in a highly selective and atom-economic manner. Mechanistic studies suggested that the cyclization process is probably mediated both by Ph3P radical cation with key 1,2-hydride transfer and hydrogen atom generated through O-H bond homolytic cleavage of Ph3P-OH radical intermediate.

Dual Chiral Catalysis Enabled Asymmetric Syntheses of Amines

Dual Chiral Catalysis Enabled Asymmetric Syntheses of Amines