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An expedient and efficient carbonylative protocol proceeded via palladium‐catalyzed tandem cyclic ketonization and carbonylative spirolactonization has been developed. This carbonylation reaction is compatible with a wide range of hydroxyalkyl ketone tethered benzyl chlorides bearing different functional groups and can be proceeded under comericially available Pd2(dba)3/BINAP catalyst system, providing a straithfowrd and practical approach to a broad range of [6,6]‐oxaspirolactones. The synthesized [6,6]‐oxaspirolactones are commonly found as core structures in natural products and can potentially serve as C2‐symmetric ligand synthons. [ABSTRACT FROM AUTHOR]

The diphosphination of alkenes through a radical pathway offers a promising approach for the rapid construction of aryl bisphosphines. However, such a synthetic strategy has not been successfully applied to the preparation of alkyl bisphosphines, partially due to the difficulties in the generation of phosphorus‐centered radicals from common alkyl phosphine compounds. We herein demonstrate that this challenge can be overcome by hiring Janus‐faced chlorophosphine as the phosphine source that can act as not only a radical precursor to generate phosphine‐centered radicals but also a radicalphile to capture alkyl radicals. With this novel strategy, a photocatalyzed reductive diphosphination reaction has been established, allowing for a straightforward synthesis of both aryl and alkyl 1,2‐bisphosphines from readily accessible alkenes and chlorophosphines. [ABSTRACT FROM AUTHOR]

The catalytic transformation of ubiquitous but inert C−N bonds is highly appealing in synthetic chemistry, but the efficient cleaving inert C−N bond and simultaneous incorporation of both the cleaved C‐moiety and N‐moiety into the desired products has been a long‐standing formidable challenge so far. Here, we developed a radical‐addition triggered cyclization and C−N bond cleavage process enabled by the unique I2/Ni or benzyl halide/Ni‐catalytic system, allowing the formal insertion of diene into the inert C−N bond. This reaction features high atom economy and enables an expedient annulative carboamination of aminodienes to diverse pyrrolidines, piperidines, and tetrahydroisoquinolines. Mechanistic studies have revealed that the reaction is initiated via the generation of a benzyl radical and the formation of quaternary ammonium salt is key for the C−N bond cleavage. [ABSTRACT FROM AUTHOR]

A novel and efficient palladium‐catalyzed regioselective and stereodivergent ring‐closing reaction of aminoenynes with aldehydes and boronic acids or hydrosilane is developed. This three‐component reaction allows for the modular synthesis of a series of exocyclic 1,3‐dienes bearing 5‐ to 8‐membered saturated N‐heterocycles. The reactions utilize a simple Pd‐catalyst and work with broad range of aminoenynes, aldehydes and organometallic reagents under mild reaction conditions. The products represent useful intermediates for chemical synthesis due to the versatility of the conjugated diene. Preliminary mechanistic details of the method are also revealed. [ABSTRACT FROM AUTHOR]

The catalytic C(sp3)−C(sp3) coupling of alkyl halides and tertiary amines offers a promising tool for the rapid decoration of amine skeletons. However, this approach has not been well established, partially due to the challenges in precisely distinguishing and controlling the reactivity of amine‐coupling partners and their product homologues. Herein, we developed a metal‐free photocatalytic system for the aminomethylation of alkyl halides through radical‐involved C(sp3)−C(sp3) bond formation, allowing for the synthesis of sterically congested tertiary amines that are of interest in organic synthesis but not easily prepared by other methods. Mechanistic studies disclosed that sterically hindered N‐substituents are key to activate the amine coupling partners by tuning their redox potentials to drive the reaction forward. [ABSTRACT FROM AUTHOR]

An efficient strategy for preventing the β‐hydride elimination of alkylpalladium species by ligation of the palladium with adjacent amino‐group was developed, which enabled a novel palladium‐catalyzed ring‐closing aminoalkylative amination of unactivated aminoenynes. The reaction is amenable to aminals, as well as aliphatic aldehydes with secondary amines, which provides straightforward access to structurally diverse exocyclic allenic amines bearing 5 to 12‐membered N‐heterocycles. With chiral phosphoramidite‐ligated palladium complex as the catalyst, an enantioselective variant was achieved with up to 93 % ee. Simultaneously, synthetic transformations of the chiral products were also conducted to afford structurally unique spirodiamines including one pharmaceutically active molecule via axial‐to‐central chirality transfer. [ABSTRACT FROM AUTHOR]

Transition‐metal mediated activation of inert chemical bonds is an ongoing topic in homogeneous catalysis. In view of the abundance and accessibility of alkylarenes and benzylamines, the use of them as benzyl source in catalytic benzylation reactions via benzylic C—H and C—N bond activation is highly desirable. Indeed, compared with the traditional approaches with benzyl halide as the substrates, benzylation reactions via C—H and C—N bond cleavage provide more efficient, atom‐economic strategies to access myriads of synthetically important molecules. In this account, our group's efforts on catalytic benzylation reactions via directed C—H activation, nondirected C—H activation and C—N bond activation are summarized. What is the most favorite and original chemistry developed in your research group? Palladium‐catalyzed aminal chemistry. How do you supervise your students? Discuss with my students and encourage them to think about where the scientific problem is. What is the most important personality for scientific research? Honesty, curiosity and passion. What are your hobbies? Reading and playing badminton. Who influences you mostly in your life? My parents, who always inspire me to go forward. What is your favorite journal(s)? Journals that fairly review the manuscripts and publish inspiring, innovative research results. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: A new strategy for the generation of the active Pd‐alkyl species from aminal via C—N bond activation has been established, in which the formation of zwitterionic intermediate through aza‐Michael addition of aminal to nitrodienes or dienones is identified as a key step for the activation of the C—N bond. The efficient strategy has enabled a new palladium‐catalyzed α‐aminomethylation of nitrodienes and dienones via double C—N bond activation. The scope and versatility of the reaction were demonstrated and a broad range of substrates bearing electron‐donating and ‐withdrawing groups on the aromatic rings were all compatible with this reaction to furnish the desired α‐aminomethylated products in moderate to good yields with excellent regioselectivities and E/Z selectivities. [ABSTRACT FROM AUTHOR]

Supporting information for this article is given via a link at the end of the document. By intercepting the acylpalladium species with C=N bond of azaarenes or imines other than free amines or alcohols, the difunctionalization of C=N bond was established via palladium‐catalyzed carbonylation/nucleophilic addition sequence. This method is compatible with a diverse range of azaarenes and imines and allows for the efficient synthesis of a wide range of quinazolinones and derivatives. The synthetic utility has been demonstrated by one‐step synthesis of evodiamine and its analogue with inexpensive starting materials. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: A new and efficient cyclization reaction has been developed to synthesize cyclic α,α‐disubstituted β‐amino esters via iron‐catalyzed intramolecular aminomethyloxygenative cyclization of diazo compounds with N,O‐aminal under mild reaction conditions. A broad range of hydroxy‐α‐diazoesters with different substituents and various N,O‐aminals were compatible with this protocol, affording the corresponding α,α‐disubstituted β‐amino esters bearing a five‐ to eight‐membered oxacycle in good yields. [ABSTRACT FROM AUTHOR]

Abstract: A new palladium‐catalyzed selective aminomethylation of conjugated 1,3‐dienes with aminals via double C—N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear α,β‐unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C—N bond to furnish a cascade double C—N bond activation, in which an allylic 1,3‐diamine and allylic 1,2‐diamine were initially formed as key intermediates through the palladium‐catalyzed C—N bond activation of aminal and the α,β‐unsaturated allylic amine was subsequently produced via palladium‐catalyzed C—N bond activation of the allylic diamines. [ABSTRACT FROM AUTHOR]

A nickel‐catalyzed alkylarylation of active alkenes with tertiary benzylamines was achieved by charge‐transfer‐complex promoted C−N bond activation. The reaction proceeded through initial Ni‐catalyzed C−N bond activation, followed by sequential radical addition, redox and proton abstraction with cleaved amine moiety in the absence of oxidant, and provides an efficient method to prepare various alkyl‐substituted oxindoles and dihydroquinolinones in good yields. [ABSTRACT FROM AUTHOR]

A series of tetradentate sp2N/ sp3N hybrid chiral N4 ligands derived from rigid chiral diamines were synthesized, which enabled the first manganese-catalyzed enantioselective epoxidation of electron-deficient alkenes with hydrogen peroxide (H2O2) as an oxidant. The reaction furnishes enantiomerically pure epoxy amides, epoxy ketones as well as epoxy esters in good yields and excellent enantioselectivities (up to 99.9% ee) with lower catalyst loading. Preliminary studies on structure-activity relationship demonstrated that maintaining comparatively lower electron-donating ability of the sp3N and relatively higher electron-donating ability of sp2N of the N4 ligands is beneficial to getting higher activity and selectivity, thus providing us a new view to understand epoxidation with H2O2. [ABSTRACT FROM AUTHOR]

A novel and catalyst-free multicomponent reaction with cyclic tertiary amines, electron-deficient aryl halides or heteroaromatic halides, and Na2S enabled by facile C−N bond cleavage of the cyclic tertiary amines was developed. This direct and operationally simple method can be applied with a wide range of functional groups and provides an efficient and rapid approach to potentially drug-like products containing amine, azaarene, thioether, or phenol ether functionalities in good to excellent yields. The utility of this method was demonstrated by the rapid synthesis of the analgesic ruzadolane. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed aminopalladation reaction followed by nucleophilic addition with aldehydes and dehydration is described. This direct and operationally simple procedure provides a rapid and reliable approach to a wide range of functionalized tetrahydroisoquinolines with high selectivity. Mechanistic studies disclosed that the nucleophilic addition, performed via a highly ordered transition-state, is the turnover-limiting step in which the inherent β-hydride elimination of the key Csp3−Pd species was controlled by the confined conformation and the nucleophilicity of the Csp3−Pd bond was enhanced by the strong electron-donating effect of the nitrogen atom. [ABSTRACT FROM AUTHOR]

An operationally simple and efficient copper-catalyzed three-component tandem reaction of terminal alkynes, diazo compounds and amines to yield β-enamino esters is described. This straightforward protocol takes place rapidly with a wide range of substrates and gives the desired β-enamino esters in good to excellent yields. Preliminary mechanistic studies suggested that the reaction probably proceeds through Cu-catalyzed formal C-H insertion to produce an alkynoate intermediate, which was then trapped by amines to give the β-enamino esters. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed C-H bond functionalization has become one of the most promising strategies to prepare complex molecules from simple precursors. However, the utilization of environmentally unfriendly oxidants in the oxidative C-H bond functionalization reactions reduces their potential applications in organic synthesis. This account describes our recent efforts in the development of a redox-neutral C-H bond functionalization strategy for direct addition of inert C-H bonds to unsaturated double bonds and a redox-green C-H bond functionalization strategy for realization of oxidative C-H functionalization with O2 as the sole oxidant, aiming to circumvent the problems posed by utilizing environmentally unfriendly oxidants. In principle, these redox-neutral and redox-green strategies pave the way for establishing new environmentally benign transition-metal-catalyzed C-H bond functionalization strategies. [ABSTRACT FROM AUTHOR]

A fundamentally novel approach to bioactive quinolizinones is based on the palladium-catalyzed intramolecular cyclocarbonylation of allylamines. [Pd(Xantphos)I2], which features a very large bite angle, has been found to facilitate the rapid carbonylation of azaarene-substituted allylamines into bioactive quinolizinones in good to excellent yields. This transformation represents the first dearomative carbonylation and is proposed to proceed by palladium-catalyzed CN bond activation, dearomatization, CO insertion, and a Heck reaction. [ABSTRACT FROM AUTHOR]

A novel and efficient palladium-catalyzed hydroaminocarbonylation of alkenes with aminals has been developed under mild reaction conditions, and allows the synthesis of a wide range of N-alkyl linear amides in good yields with high regioselectivity. On the basis of this method, a cooperative catalytic system operating by the synergistic combination of palladium, paraformaldehyde, and acid was established for promoting the hydroaminocarbonylation of alkenes with both aromatic and aliphatic amines, which do not react well under conventional palladium-catalyzed hydroaminocarbonylation. [ABSTRACT FROM AUTHOR]

A convenient and efficient iron-catalyzed nucleophilic addition of simple alkenes to isochroman acetals has been established for the synthesis of 1-alkenyl isochromans. In the presence of 5-20 mol % iron(III) p-toluenesulfonate, the alkenyl functionalized isochromans were prepared in moderate to excellent yields. This transformation provides a novel methodology for the synthesis of 1-alkenyl isochromans from simple alkenes and isochroman acetals. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed intramolecular CH bond sulfuration reaction of aryl thiocarbamates has been developed. This strategy provides a new route to benzo[ d][1,3]oxathiol-2-ones with tolerance of a wide range of substituents. Mechanistic studies suggested that the CH activation-sulfuration to afford 2-imino-1,3-benzoxathiole intermediate might involve an electrophilic palladation process. [ABSTRACT FROM AUTHOR]

A new and atom-economic palladium-catalyzed aminomethylamination of allenes with aminals by CN bond activation is described. This direct and operationally simple method provides a fundamentally novel approach for the synthesis of 1,3-diamines. Mechanistic studies suggest that a unique cationic π-allylpalladium complex containing an aminomethyl moiety is generated as a key intermediate through the carbopalladation of the allene with a cyclometalated palladium-alkyl species. [ABSTRACT FROM AUTHOR]

A rhodium(III)-catalyzed direct selective C-2 alkenylation reaction of indoles with alkenes has been developed with molecular oxygen as the sole oxidant. The rhodium/oxygen catalytic system is applicable to a broad range of indoles and alkenes, which provides a novel access to various C-2 alkenylated indoles and pyrroles. [ABSTRACT FROM AUTHOR]

An efficient Ru catalyst constructed from simple and commercially available triphenylphosphane and enantiopure (1 S,1′ S)-1,1′-biisoindoline (BIDN) was applied to the asymmetric hydrogenation of aromatic ketones. A range of simple aromatic ketones could be hydrogenated with good to excellent enantioselectivities (up to 95 % ee). An appropriate enantioselective transition state was proposed to explain the high enantioselectivity obtained with this catalytic system. This study represents the first example to establish a practical Noyori-type catalyst with a simple achiral monophosphane for highly enantioselective hydrogenation. [ABSTRACT FROM AUTHOR]

A conceptually new cooperative catalytic system via a synergistic combination of aldehyde and copper catalysis has been established based on systemic mechanistic studies. This new cooperative catalysis has been successfully applied in the direct aerobic oxidative CH amination of azoles at room temperature, which was previously realized under harsh conditions. Mechanistic studies including isotopic labeling experiments and kinetic isotope effect (KIE) experiments support a reaction pathway that involves formation of an aminal, hydrolysis of the aminal to generate the copper-amide species, subsequent CH amination and re-oxidation of copper(I) to copper(II) by oxygen. It not only provides an efficient method to realize the oxidative CH amination of benzoxazoles with free amines at room temperature, but also paves the way for establishing new CN bond formation reactions by using this efficient cooperative catalysis. [ABSTRACT FROM AUTHOR]

The Lewis acid-catalyzed conjugate addition of 2-alkylazaarenes to methylenemalononitriles through sp3 CH bond functionalization has been developed, which provides an efficient and reliable method for incorporation of the nitrile group into the heterocycles. [ABSTRACT FROM AUTHOR]

The direct CH benzylation of azoles with benzyl chlorides proceeds efficiently, via sequential cleavage of one sp2 CH bond and two sp3 CH bonds in the presence of a palladium catalyst, to generate a wide range of tribenzylated azoles with a quaternary carbon center efficiently. The same catalyst could also promote the mono- and di-benzylation reactions through fine turning of the base and reaction conditions. [ABSTRACT FROM AUTHOR]

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Review: 380 refs. [ABSTRACT FROM AUTHOR]