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Herein, we report a modular and convergent strategy for the assembly of atropisomeric o-terphenyls with 1,2-diaxes via palladium/chiral norbornene cooperative catalysis and axial-to-axial diastereoinduction. Readily available aryl iodides, 2,6-substituted aryl bromides, and potassium aryl trifluoroborates are used as the building blocks, laying the foundation for diversity-oriented synthesis of these scaffolds (46 examples). Other features include the unique axial-to-axial diastereoinduction mode, construction of two axes in a single operation, and step economy. DFT calculations are performed to rationalize the axial-to-axial diastereoinduction process. Synthetic utilities of this method in preparation of atropisomeric oligophenyls, chiral catalysts, and ligands are demonstrated.

Axially chiral biaryls are common structural motifs in functional materials, bioactive natural products, pharmaceuticals and chiral catalysts/ligands. As such, efficient preparation of these privileged scaffolds is an important endeavour in organic chemistry. Herein we report a general and modular platform technology for the construction of axial chirality via palladium/chiral norbornene cooperative catalysis. It is a three-component cascade process that involves widely available aryl iodides, 2,6-substituted aryl bromides and olefins (or alkynes, boronic acids and so on) as the reactants. A wide variety of substrates bearing an assortment of functional groups (88 examples) are compatible with this method. Other features include a distinct stereoinduction model, excellent enantioselectivities, step economy and scalability. This method is also amenable for the synthesis of chiral fluorenols through axial-to-central chirality transfer in high stereochemical fidelity. We anticipate that this work will have broad synthetic utilities in chiral ligands and catalyst-design for asymmetric catalysis. Axial chirality is found in many important compounds, such as bioactive molecules and catalytic components. Now palladium and chiral norbornene cooperative catalysis is reported for the construction of atropisomeric biaryls and chiral fluorenols.

A cooperative catalytic system involving a Pd/XPhos complex and inexpensive 5-norbornene-2-carbonitrile that enables the use of alkyl tosylates as alkylating reagents in the Catellani reaction has been developed. This mild, scalable protocol is compatible with a range of readily available functionalized aryl iodides and alkyl tosylates, as well as terminating olefins (45 examples, up to 97% yield).

Herein we report an asymmetric two-component vinylogous Catellani reaction for the construction of C-N axial chirality through a palladium/chiral norbornene cooperative catalysis and an axial-to-axial chirality transfer process. Various partially aromatic iodinated 2-pyridones, quinolones, coumarin and uracil substrates react with 2,6-disubstituted aryl bromides with a tethered amide group, to afford a wide variety of polycyclic C-N atropisomers (39 examples, up to 97% ee ). The obtained C-N axial chirality is originated from the preformed transient C-C axial chirality with high fidelity. The synthetic utility of this chemistry is demonstrated by facile preparation of complex quinoline and pyridine based C-N atropisomers through a N -deprotection and aromatization sequence. In addition, a remote axial-to-central diastereoinduction process dictated by C-N axial chirality is observed with excellent diastereocontrol. This research opens a new avenue for asymmetric synthesis.

Herein, we report a modular and convergent strategy for the assembly of atropisomeric

Mediators play a central role in Catellani-type reactions. Herein we reported the discovery of inexpensive 5-norbornene-2-carboxylic acid (N4) as a general catalytic mediator (20 mol%) to facilitate ortho C–H activation and the following C–C bond formation of aryl iodides. Firstly, a cooperative catalytic system comprising N4 and a palladium/XPhos complex was developed for the novel Catellani/redox-relay Heck cascade to construct tetrahydronaphthalenes and indanes that contain a quaternary carbon stereogenic center. The striking feature of this work was the avoidance of stoichiometric NBE mediator that are usually required for Catellani-type reactions. Then, preliminary results demonstrated that N4 could act as a general catalytic mediator to replace NBE for other Catellani-type reactions, which will undoubtedly inspire future developments in the field of cooperative catalysis. Finally, control experiments indicated that the carboxylic acid moiety of N4 plays an essential role in its ability to serve as a superior mediator.

Herein we report a highly enantioselective kinetic resolution of tertiary benzyl alcohols via palladium/chiral norbornene cooperative catalysis. With simple aryl iodides as the resolution reagent, a wide range of readily available racemic tertiary benzyl alcohols are applicable to this method. Both chiral tertiary benzyl alcohols and benzo[c]chromene products are obtained in good to excellent enantioselectivities (selectivity factor up to 544). The appealing synthetic utility of the obtained enantioenriched tertiary alcohols is demonstrated by the facile preparation of several valuable chiral heterocycles. Preliminary mechanism studies include DFT calculations to explain the origin of enantiodiscrimination and control experiments to uncover the formation of a transient axial chirality during the kinetic resolution step.

Reported is a novel palladium(II)-initiated Catellani-type reaction that utilizes widely accessible aryl boronic acids as the substrates instead of aryl halides, thereby greatly expanding the existing scope of this powerful transformation. This borono-Catellani reaction was promoted by cooperative catalysis between Pd(OAc)2 and the inexpensive 5-norbornene-2-carbonitrile. Practicality is the striking feature of the reaction: it is run open to air at ambient temperature and no phosphine ligand is needed. This mild, chemoselective, and scalable protocol is compatible with a large range of readily available functionalized aryl boronic acids and bromides, as well as terminating olefins (50 examples, 39-97 % yields). Moreover, the orthogonal reactivity between the borono-Catellani and classical Catellani reaction was demonstrated. This work is expected to open new avenues for developing novel Catellani-type reactions.

A cooperative catalytic system comprising a palladium/XPhos complex and 5-norbornene-2-carboxylic acid was developed. This system promotes a two-component annulation reaction, allowing the construction of tetrahydronaphthalenes and indanes that contain quaternary centers through consecutive Catellani-type C–H activation and redox-relay Heck reaction. Inexpensive 5-norbornene-2-carboxylic acid acts as a catalytic mediator (20 mol %) in this process. This mild, scalable, and chemoselective protocol is compatible with a wide variety of readily available aryl iodides and alkylating reagents. Application of this method in a 4-step synthesis of opioid analgesic eptazocine is demonstrated. Preliminary studies underscore the future promise of rendering this Catellani/redox-relay Heck cascade enantioselective.

A cooperative catalytic system comprising a Pd/XPhos complex and a potassium salt of 5-norbornene-2-carboxylic acid to promote the annulation between aryl iodides and epoxides was developed, thereby providing highly convergent access to valuable 2,3-dihydrobenzofuran (DHBF) scaffolds. The unique potassium salt of the inexpensive 5-norbornene-2-carboxylic acid serves as a highly efficient catalytic mediator (10 mol%), which leads to fewer side reactions. The salient features of the reaction include its broad substrate scope (with respect to both aryl iodides and epoxides), its high atom economy and good chemo-selectivity. Furthermore, no extra base is needed for the process.

Remote C-H bond functionalization of arenes with precise control is a recognized extraordinary challenge in organic synthesis. Recently, Yu and Houk et al. developed an elegant strategy to distinguish and functionalize remote Csp2-H bonds of (hetero)arenes within one-bond distance by the interplay of a remote directing template and a transient norbornene-type mediator. A wide range of medicinally important benzoazines are well compatible with this method. The chemistry significantly expands the toolbox for site-selective functionalization of remote Csp2-H bond of (hetero)arenes. This work has been published in Nature Chemistry in March, 2020.

We report a dual-tasked methylation that is based on cooperative palladium/norbornene catalysis. Readily available (hetero)aryl halides (39 iodides and 4 bromides) and inexpensive MeOTs or trimethylphosphate are utilized as the substrates and methylating reagent, respectively. Six types of "ipso" terminations can modularly couple with this "ortho" C-H methylation to constitute a versatile methylation toolbox for preparing diversified methylated arenes. This toolbox features inexpensive methyl sources, excellent functional-group tolerance, simple reaction procedures, and scalability. Importantly, it can be uneventfully extended to isotope-labeled methylation by switching to the corresponding reagents CD3OTs or 13CH3OTs. Moreover, this toolbox can be applied to late-stage modification of biorelevant substrates with complete stereoretention. We believe these salient and practical features of our dual-tasked methylation toolbox will be welcomed by academic and industrial researchers.

A palladium/norbornene cooperative catalysis promoted annulation involving an ortho-C-H amination and intramolecular Heck cascade between aryl iodides and functionalized amination reagents is reported, thereby providing a highly convergent access to the unique N-containing bridged scaffolds: hexahydro-2,6-methano-1-benzazocine. The salient features of the reaction include its broad substrate scope (with respect to aryl iodides), its high step economy, and good chemoselectivity. Preliminary studies underscore the future promise of rendering this Catellani-type annulation enantioselective.

The Catellani reaction is a powerful strategy that allows the expeditious synthesis of highly substituted arenes, which are not easily accessible through traditional transition-metal-catalyzed cross-coupling reactions. This reaction utilizes the synergistic interplay of palladium and norbornene catalysis to facilitate sequential ortho-C-H functionalization and ipso termination of aryl iodides in a single operation. Since pioneering work by the group of Catellani in 1997, and later by the group of Lautens, this chemistry has attracted considerable attention from the synthetic chemistry community. Dramatic progress has been made by a number of groups in the past two decades. In this Minireview, the alkylating reagents employed in this intriguing reaction and the corresponding applications in organic synthesis are summarized; thus complementing existing reviews to inspire future developments.

A palladium-catalyzed (3 + 2) cycloaddition of vinyl cyclopropane and α,β-unsaturated imines generated in situ from aryl sulfonyl indoles is reported. The reaction proceeds with high diastereoselectivity to provide the optically enriched spirocyclopentane-1,3'-indolenines in up to 74% yield and with up to 97% ee, which contains an all-carbon quaternary center and two tertiary stereocenters. The reaction involves a first conjugate addition of the carbon anion of zwitterionic π-allylpalladium complex from vinyl cyclopropane to the in situ formed unsaturated imine followed by a palladium-catalyzed intramolecular C3-allylation of indole.

The ship-borne satellite earth station was studied to establish a hardware-in-loop simulation system for employee training. Preliminary demand analysis for staff of all levels shows the complexity of this system. Based on the distributed simulation theory of HLA, system framework and implementation approach was proposed. Key technologies for modeling and simulation of ship-borne satellite earth station were discussed in this article. Subsequently the block diagrams of device simulator and simulation agent were clearly described. Finally the specific steps of operation were created to show the details of actual running process, which prove the feasibility of this system.

Palladium-catalyzed enantioselective cycloaddition of vinyl cyclopropane dicarbonitriles and nitroolefins was achieved to generate structurally and optically enriched nitrocyclopentanes with three consecutive chiral carbon centers in up to 96 % yield and with up to 92 % ee. The two diastereoisomers produced in each reaction are readily separable by simple chromatography. The present method allows the preparation of both diastereoisomers in optically enriched form.

Palladium-catalyzed enantioselective cycloaddition of vinyl cyclopropane dicarbonitriles and nitroolefins was achieved to generate structurally and optically enriched nitrocyclopentanes with three consecutive chiral carbon centers in up to 96 % yield and with up to 92 % ee. The two diastereoisomers produced in each reaction are readily separable by simple chromatography. The present method allows the preparation of both diastereoisomers in optically enriched form.

The unsaturated imines, involved in the title [3+2] cycloadditions, are generated in situ from aryl sulfonyl indoles [(I) and (IV)].