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The preparation of ferrocenes with both axial and planar chiralities poses a considerable challenge. Herein we report a new strategy for the construction of both axial and planar chiralities in a ferrocene system via palladium/chiral norbornene (Pd/NBE*) cooperative catalysis. In this fascinating domino reaction, the firstly established axial chirality is dictated by Pd/NBE* cooperative catalysis, while the latter planar chirality is controlled by the pre-installed axial chirality through a unique axial-to-planar diastereoinduction process. This method exploits readily available ortho-ferrocene-tethered aryl iodides (14 examples) and the bulky 2,6-disubstituted aryl bromides (14 examples) as the starting materials. 5- to 7-membered benzo-fused ferrocenes with both axial and planar chiralities (29 examples) are obtained in one step with constantly excellent enantioselectivities (> 99% e.e.) and diastereoselectivities (> 19:1 d.r.).

A palladium-catalyzed [4 + 3] annulation of 2-bromobiphenyls and epoxides for the construction of dihydrodibenzo[b,d]oxepines is reported.

The kinetic resolution (KR) of racemates is one of the most widely used approaches to access enantiomerically pure compounds. Over the past two decades, catalytic nonenzymatic KR has gained popularity in the field of asymmetric synthesis due to the rapid development of chiral catalysts and ligands in asymmetric catalysis. Chiral tertiary alcohols are prevalent in a variety of natural products, pharmaceuticals, and biologically active chiral compounds. The catalytic nonenzymatic KR of racemic tertiary alcohols is a straightforward strategy to access enantioenriched tertiary alcohols. This short review describes recent advances in catalytic nonenzymatic KR of tertiary alcohols, including organocatalysis and metal catalysis.1 Introduction2 Organocatalysis2.1 Peptide Catalyst2.2 Chiral Phosphoric Acid Catalyst2.3 Chiral Lewis Base Catalyst2.4 Chiral Quaternary Ammonium Salt Catalyst3 Metal Catalysis3.1 Mixed La-Li Heterobimetallic Catalyst3.2 Rh Catalyst3.3 Hf Catalyst3.4 Pd Catalyst3.5 Cu Catalyst3.6 Ag Catalyst4 Conclusion and Outlook

This paper considers the output feedback stabilization problem of linear systems with infinite distributed delays in their inputs and outputs. A low gain observer is proposed to estimate the state of the concerned system with infinite distributed delays in its inputs and outputs. The observer based output feedback controller is then developed. It is shown that the resulting closed loop system is globally asymptotically stable. It should be pointed out that the output feedback control problem of linear systems with infinite distributed input and output delays is first time investigated to the best of our knowledge. Finally, some numerical examples are presented to demonstrate the effectiveness of the proposed controller.

A concise total synthesis of (±)-stepharine and (±)-pronuciferine using readily available reagents as the starting materials is reported. This synthesis features a three-component Catellani reaction/Au-catalyzed 6-exo-dig cyclization for the assembly of 1-methylene-tetrahydroisoquinoline scaffold and an oxidative dearomatization for constructing spiro-cyclohexadienone scaffold.

This paper considers the leaderless consensus problem of linear time-invariant multi-agent systems with infinite distributed communication delays. A novel distributed low gain controller is proposed based on the solution to a parametric algebraic Riccati equation. It is shown via the newly developed Lyapunov-like method that not only the consensus of linear time-invariant multi-agent systems can be achieved exponentially under some mild assumptions but also an estimate of the exponential convergence rate of consensus is given in this work. The Lyapunov-like method is also extended to handle a special case of linear time-varying multi-agent systems. In addition, the obtained results include the results on the leaderless consensus of linear multi-agent systems with bounded distributed communication delays as special cases. To the best of our knowledge, this is the first work that develops the Lyapunov-like method for the leaderless consensus problems of both time-invariant and time-varying linear multi-agent systems with infinite distributed communication delays. Finally, a numerical example is presented to illustrate the effectiveness of the proposed controller.

Nitroaromatics are tremendously valuable organic compounds with a long history of being used as pharmaceuticals, agrochemicals, and explosives as well as vital intermediates to a wide variety of chemicals. Consequently, the exploration of aromatic nitration has become an important endeavor in both academia and industry. Herein, we report the identification of a powerful nitrating reagent, 5-methyl-1,3-dinitro-1

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.

Reported here is a concise total synthesis of (-)-berkelic acid in eight linear steps. This synthesis features a Catellani reaction/oxa-Michael cascade for the construction of the isochroman scaffold, a one-pot deprotection/spiroacetalization operation for the formation of the tetracyclic core structure, and a late-stage Ni-catalyzed reductive coupling for the introduction of the lateral chain. Notably, four stereocenters are established from a single existing chiral center with excellent stereocontrol during the deprotection/spiroacetalization process. Stereocontrol of the intriguing deprotection/spiroacetalization process is supported by DFT calculations.

Recent years have witnessed palladium-catalyzed C–H activation emerging as a versatile strategy for the construction of valuable scaffolds. Palladacyclopentane-type intermediates, usually created by C–H activation from an aryl-Pd(II) precursor, provide opportunities for subsequent C–H hetero-functionalizations and have therefore received much attention in organic synthesis. In this review article, we summarise recent advances in the C–H hetero-functionalization of arenes through palladacyclopentane-type intermediates over the past decade.

1,3-trans-Disubstituted tetrahydroisoquinoline (THIQ) is a common heterocyclic structural unit of naphthylisoquinoline alkaloids. The assembly of this structural unit is not trivial, which constitutes a substantial challenge in the total synthesis of naphthylisoquinoline alkaloids and related pharmaceuticals. Herein, we report a modular and convergent method for the rapid assembly of 1,3-trans-disubstituted THIQ frameworks through a three-component Catellani reaction and a Au

We report the construction of a molecular vise by pairing a tritopic phenylphosphorus(III) linker and a monotopic linker in opposite positions within a metal-organic framework. The angle between these linkers at metal sites is fixed upon changing the functionality in the monotopic linker, while the distance between them is precisely tuned. This distance within the molecular vise is accurately measured by 1H-31P solid-state nuclear magnetic resonance spectroscopy. This unveils the impact of the distance on catalytic performance without interference from electrostatic effects or changes in the angle of the ligand, which is unprecedented in classic organometallic complexes.

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 convergent approach to assemble the fused BCDE tetracyclic framework of wortmannin is presented. This route features a very challenging Suzuki-Miyaura coupling to prepare the fully functionalized furan intermediate, a Negishi-type acylation to unite the two enantio-enriched fragments, and a subsequent hydrogen-atom-transfer-initiated 6-endo radical cyclization to install the central cyclohexadienone moiety, which establishes the C10 all-carbon quaternary stereocenter.

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).

Reported is a cooperative catalytic system consisting of a complex of Pd with dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (XPhos) and the potassium salt of 5-norbornene-2-carboxylic acid that permits the use of epoxides as dual-functionalized alkylating reagents in Catellani-type reactions for the assembly of heterocycles. Salient features of this research include readily available substrates, use of the potassium salt of 5-norbornene-2-carboxylic acid as a catalytic mediator as well as a base, and excellent regioselectivity for the cleavage of epoxides. This mild, chemoselective, scalable, atom- and step-economic protocol offers a straightforward approach for the assembly of isochroman and 2,3-dihydrobenzofuran scaffolds.

Reported is a modular strategy for the preparation of the unique benzofused dioxabicycle scaffolds involving a Catellani reaction of aryl iodides, epoxides, and terminal alkynes and an oxa-cyclizat...

Reported is the borono-Catellani arylation process for unsymmetrical biaryls synthesis, utilizing the readily available pinacol ester of arylboronic acids, aryl bromides, and olefins as the reactants. The distinct reactivity of arylboronic ester and aryl bromides secures the excellent chemoselectivity in the pivotal arylation step. The reaction is enabled by the cooperative catalysis of Pd(OAc)2 and the NBE derivative N7, with molecular oxygen as the terminal oxidant.

The Catellani reaction is known as a powerful strategy for the expeditious synthesis of highly substituted arenes and benzo-fused rings, which are usually difficult to access through traditional cross-coupling strategies. It utilizes the synergistic interplay of palladium and norbornene catalysis to facilitate sequential ortho C-H functionalization and ipso termination of aryl halides in a single operation. In classical Catellani-type reactions, aryl halides are mainly used as the substrates, and a Pd0 catalyst is required to initiate the reaction. Nevertheless, recent advances showcase that Catellani-type reactions can also be initiated by a PdII catalyst with different starting materials instead of aryl halides via different reaction mechanisms and under different conditions. This emerging concept of PdII /norbornene cooperative catalysis has significantly advanced Catellani-type reactions, thus enabling future developments of this field. In this Minireview, PdII -initiated Catellani-type reactions and their application in the synthesis of bioactive molecules are summarized.

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.

A palladium(ii)/norbornene cooperative catalysis enabled redox-neutral ortho-C-H amination of pinacol aryl- or heteroarylborates for the synthesis of structurally diverse anilines is reported. This method is scalable, robust (tolerance of air and moisture), phosphine ligand-free, and compatible with a wide range of functionalities. These practical features make this reaction amenable for industry. A plethora of synthetically very useful halogenated anilines, which often cannot be prepared via other transition-metal-catalyzed aminations, are readily produced using this method. Particularly, the orthogonal reactivity between pinacol arylborates and aryl iodides is demonstrated. Preliminary deuterium-labeling studies reveal a redox-neutral ipso-protonation mechanism of this process, which will surely inspire the future development of this field. Overall, the exceptionally broad scope (47 examples) and reliability of this procedure, together with the wide availability of pinacol arylborates, make this chemistry a valuable addition to the existing methods for aniline synthesis.

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.

Heterocycles 2-pyridone and uracil are privileged pharmacophores. Diversity-oriented synthesis of their derivatives is in urgent need in medicinal chemistry. Herein, we report a palladium/norbornene cooperative catalysis enabled dual-functionalization of iodinated 2-pyridones and uracils. The success of this research depends on the use of two unique norbornene derivatives as the mediator. Readily available alkyl halides/tosylates and aryl bromides are utilized as ortho-alkylating and -arylating reagents, respectively. Widely accessible ipso-terminating reagents, including H/DCO2Na, boronic acid/ester, terminal alkene and alkyne are compatible with this protocol. Thus, a large number of valuable 2-pyridone derivatives, including deuterium/CD3-labeled 2-pyridones, bicyclic 2-pyridones, 2-pyridone-fenofibrate conjugate, axially chiral 2-pyridone (97% ee), as well as uracil and thymine derivatives, can be quickly prepared in a predictable manner (79 examples reported), which will be very useful in new drug discovery., Diversity-oriented synthesis of 2-pyridone and uracil derivatives is in urgent need in medicinal chemistry as they are useful pharmacophores. Here the authors show that palladium/norbornene cooperative catalysis enabled dual-functionalization of iodinated 2- pyridones and uracils.

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

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.

In this paper, the adaptive event-based control approach is applied to study leader-following consensus of multi-agent systems with linear dynamic models. Adaptive event-based controller and triggering function for each agent are designed, where the adaptive function is only dependent on its own event time instants. A sufficient condition on consensus is proposed, which shows that the adaptive event-based method presented in this paper not only can reduce the communication among neighboring agents, but also can determine the event time instants for each agent without using the global information. Furthermore, the Zeno-behavior for the concerned closed-loop system is excluded. Finally, an example is presented to illustrate the effectiveness of the obtained theoretical results.

This paper investigates the consensus problem of multi-agent systems (MASs) described by linear dynamic models. In order to avoid using the global information and reduce communication burden, the distributed adaptive event-based control approach is presented. Some novel triggering functions and control protocols are designed. The obtained results show that consensus can be achieved only with local information and communicating with neighbors continually is avoided as well. In addition, the Zeno-behavior for the concerned closed-loop system is excluded. Finally, a numerical example is provided to validate the availability of the obtained theoretical results.

Reported is a modular one-step three-component synthesis of tetrahydroisoquinolines using a Catellani strategy. This process exploits aziridines as the alkylating reagents, through palladium/norbornene cooperative catalysis, to enable a Catellani/Heck/aza-Michael addition cascade. This mild, chemoselective, and scalable protocol has broad substrate scope (43 examples, up to 90 % yield). The most striking feature of this protocol is the excellent regioselectivity and diastereoselectivity observed for 2-alkyl- and 2-aryl-substituted aziridines to access 1,3-cis-substituted and 1,4-cis-substituted tetrahydroisoquinolines, respectively. Moreover, this is a versatile process with high step and atom economy.

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.