A cascade C-H activation, annulation and etherification protocol of N-hydroxybenzamides with propargylamines provides a flexible and powerful route to N-alkoxylated 3-arylisoindolin-1-ones. Three new bonds (C-C, C-N, and C-O) are generated to afford a series of isoindolin-1-ones bearing a tetrasubstituted carbon in 49% to 82% yields. The utility of this method is showcased by gram-scale synthesis,

The reaction of non-fluorinated silyl enol ether with alkyne is useful for the synthesis of β,γ-unsaturated carbonyl compounds. However, most of the existing methods for realizing such organic transformation usually employ stoichiometric amounts of relatively expensive Lewis acids/metallic salts. Herein, an iron(III)-catalyzed difluoroalkylation of aryl alkynes with difluoroenol silyl ether was developed

An electrochemical oxidative C-H/S-H cross-coupling reaction between acetonitrile and heteroaryl thiols has been developed. Me4NBr is employed as a redox catalyst to oxidize both the Csp3-H of acetonitrile and S-H of heteroaryl thiols. Heteroaryl vinyl sulfides were afforded under metal-free and oxidant-free reaction conditions in good yields and stereoselectivities with excellent functional group

We present an efficient method for forming C-N bonds via intramolecular amidation catalyzed by well-defined Cp*Co(N,O)I complexes. The reaction has been operate under mild conditions and produced a regioselective amidation product without the use of a bulky anion or expensive fluorinated solvents. The Cp*Co(N,O)-I catalyst is very effective for intramolecular benzylic, tertiary, and internal C(sp3)-H

We herein developed a protocol for the asymmetric synthesis of artificial AAs featuring a 3-spiropyrrolidine oxindole skeletal with continuous tetrasubstituted carbon stereocenters by a 1,3-dipolar cycloaddition reaction of in situ generated azomethine ylides with a chiral dehydroalanine Ni(II) complex. A three-component reaction of the Ni(II) complex with various isatins and AAs in green solvent (ethanol)

A transition-metal-free aminocyanation of aryl alkynes has been achieved using indium tribromide, InBr3 or B(C6F5)3 as a Lewis acid. This aminocyanation protocol features with non-toxic cyanide source, a good substrate scope and valuable aminocyanation products. Mechanistic studies reveal the complex formation between Lewis acid and alkyne to produce in situ alkyne nitrile as a key intermediate. Further

We report a procedure for the multigram synthesis of 4-(dimethylamino)pyridinium azide, stable, non-explosive, low-hygroscopic source of azide ion soluble in both protic and aprotic organic solvents. In protic ionic liquid media this reagent was shown to serve as a safer equivalent of toxic and unstable hydrazoic acid. The high synthetic utility of this system was demonstrated using donor-acceptor

A direct C-H phosphonylation of pyridine by N-benzylating activation is reported, which afforded 4-pyridylphosphine oxides with high regioselectivity, without the employment of metal catalyst or expensive activator. By increasing the electrophilicity of pyridinium with electron-withdrawing substituents on the N-benzyl group, the phosphonylation process could be realized at room temperature. Control

Cross dehydrogenative coupling (CDC) reactions have become a convenient synthetic strategy for the synthesis of various (het)aromatic scaffolds. In recent times ball milling (BM) has emerged as a powerful tool to perform reactions in a greener way. The current review highlights various applications of cross dehydrogenative coupling reactions under ball milling towards synthesis of useful molecules

We report herein a catalytic synthetic method for enantioenriched N-substituted pyridones. By employing chiral iridium catalyst generated from the Carreira [P/olefin] ligand, intermolecular asymmetric allylic amination of allyl alcohols with pyridones proceeded smoothly with excellent chemo-, regio- and enantio-selectivities (>19:1 N/O, >19:1 b/l and ≥89% ee). The reaction underwent through a kinetic

Halohydrin dehalogenases (HHDHs) possess an unnatural activity of introducing functionalities such as N3, CN, NO2 etc., into a molecule through the ring-opening reaction of epoxides. The enantioselectivity of HHDHs is substrate-dependent and not always high enough for synthetic applications. B-group of HHDHs has been neglected in the past, due to observed low enantioselectivity based on performance

An intramolecular C-H amination for the synthesis of carbazoles with a Pd(II)/ TBPB system has been developed. This catalytic amination process forms the carbazole products in good to excellent yields. It is noteworthy that this method implied the advantages of the catalytic mode involving perester with transition metal catalyst in the activation of inert C-H bonds. In addition, the transformation

A synthetic strategy for the construction of 2,2-disubstituted indolin-3-ones from 2-alkynylnitroarenes and ketones has been described. The corresponding indolin-3-one derivatives were afforded in moderate to excellent product yields by using mild conditions. After a Wittig-like process, the key intermediates 3H-indol-3-ones were generated from 2-alkynylnitroarenes, which could be further transformed

Catalysts generated by combinations of Pd(TFA)2 and pyridine-hydrazone ligands have been applied to 1,2 addition of arylboronic acids to aliphatic N-carbamoyl (Cbz) hydrazones, affording protected α-aryl monoalkylhydrazines with high enantioselectivities (37-99% ee). Subsequent removal of the benzyloxy carbonyl protecting group provides a direct entry to free monosubstituted hydrazines, key building

Enantiomers of chiral substances typically have distinct biological activities, thus, the explorations of biochemical processes at the enantiomeric level has has very high significance. This study investigated DNA polymerase–catalyzed reaction modulated by various types of chiral cobalt complexes. The experimental data showed that polymerase reactions were inhibited or accelerated in the presence of

An electrochemical decarboxylative aminomethylation reaction of imidazo[1,2-a]pyridines with various N-substituted glycines in acetonitrile at room temperature has been described. The reaction could be conducted under light-free, catalyst-free, oxidant-free, and air conditions, affording the C3-aminomethylated imidazo[1,2-a]pyridines in good to high yields. Remarkably, N-aryl, N,N-dialkyl, and N-alkyl-N-aryl

Saturated N-heterocycles are prominent motifs found in various natural products and pharmaceuticals. Despite the increasing interest in this class of compounds, the synthesis of saturated bicyclic azacycles requires tedious multi-step syntheses. Herein, we present a one-pot protocol for the synthesis of octahydroindoles, decahydroquinolines, and octahydroindolizines through a cascade reaction.

Heterocyclic N-oxides are prevalent in numerous natural products with broad applications in pharmaceuticals, agrochemicals, material sciences, and asymmetric synthesis. Owing to their profound biological and physiological activity and unique chemical reactivity, the importance of these compounds has stimulated substantial interest among organic synthetic chemists. More importantly, C-2 functionalization

A general method is developed to allow de novo construction of quinolines and C2-functionalized quinolines from ortho-alkenyl anilines in the presence of a difluorocarbene precursor. This method exploits a crucial reactivity of in-situ generation of isocyanides from condensation of primary aniline with difluorocarbene. Subsequent α-addition of isocyanide by neighbouring alkenyl group constructs the

Functionalization of white phosphorus with disulfides, amines and KOH to phosphoramidodithioates containing both P−N, P−S and P=O bonds via a four-component reaction is presented. It proceeds with high yields and provides an attractive approach for the construction of valuable N−P(O)−S motif using a one-step strategy. The advantages of this newly developed process include a clean reaction profile,

The ylide-functionalized diisopropyl phosphine (prYPhos) promotes Pd-catalyzed Suzuki-Miyaura couplings of aryl chlorides and bromides with arylboronic acids. Using Pd2(dba)3/prYPhos as the catalyst and K2CO3 as the base, various (hetero)biaryls were synthesized in 45–98% yields at mild reaction conditions, tolerating sensitive functional groups and steric hindrance. The electron rich, sterically demanding

The “borrowing hydrogen” (BH) method for C-alkylation reactions using alcohol as alkylating agents is an important synthetic transformation. In this respect, designing cheap and bench stable earth abundant metal catalyst for borrowing hydrogen transformation is a key challenge to be witnessed. Herein we have presented a synthesis of non-phosphine, easily accessible and bench stable SNS−Ni complexes

Reported herein is a photocatalytic platform for the vicinal aminopyridylation of indoles. The accurate difunctionalization reaction undergoes a tandem process involving a radical-mediated 1,3-dipolar cycloaddtion which generated from the single-electron oxidation of N-aminopyridinium ylides, a cleavage of the N−N bond as well as an oxidation of indoline ring. The electrophilic pyridyl and nucleophilic

A synthetic method of o-sulfanylanilines from cyclohexanones, amines, and thiophenols under transition-metal-free conditions is disclosed. This is the first report on the direct thioamination of cyclohexanones via N-iodosuccinimide (NIS) promoted oxidative dehydroaromatization. Non-aromatic cyclohexanones were smoothly dehydrogenated, and acted as an aryl source using oxygen as a green oxidant. The

Organosilicon reagents are highly versatile and privileged scaffolds in modern synthetic chemistry, largely due to the range of transformations the groups are amenable to. The β-Silicon effect is one of the fundamental phenomena underpinning the inherent reactivity of organosilicon reagents, allowing unsaturated organosilanes to undergo a range of electrophilic substitutions with a variety of nucleophiles

A ruthenium(II)-catalyzed hydroamination of allenoates with arylamines has been developed. This strategy provides an approach to synthesize E-allylic amines in good yields with high atom-economy and high levels of chemo-, regio- and E-selectivities with a broad substrate scope.

An operationally simple protocol for the synthesis of medium-sized lactones and macrolactones via an intramolecular ring expansion of cyclic ketones has been developed. Using this method, a series of 10- and 12-membered lactones was synthesized under mild conditions. Preliminary mechanistic studies showed that a radical pathway might be involved in this reaction.

The acidic hydrogen-tethered allylic carbonates were successfully applied in phosphine catalysis. Their (4+2) annulation reaction with sulfamate-derived cyclic imines under phosphine catalysis worked well to produce tetrahydropyridine-fused heterocyclic compounds in high yields. A moderate ee was obtained in the initial screening. The zwitterionic intermediate produced through in-situ deprotonation

The direct asymmetric addition of heteroatom nucleophiles to imines represents one of the most efficient tools for the formation of carbon-heteroatom bonds and has received much interest recently. The review is devoted to the asymmetric addition reactions of non-carbon nucleophiles to imines. The present review is divided into five main sections: reactions with N-nucleophiles; reactions with P-nucleophiles;

Difunctionalization of alkenes enables construction of complex compounds in one pot. In this report, we presented an intermolecular, redox-neutral three-component dicarbofunctionalization of activated alkenes under mild reaction conditions. The mechanistic studies indicated tertiary alkyl radicals from oxalate salts were first added to alkenes in Giese-type fashion, followed by nucleophilic addition

An atom-economical approach for the synthesis of 3-aminofurans/thiophenes via a conjugate addition of alcohols and thiols with electron withdrawing groups (EWGs) at α positions on alkynenitriles followed by a modified Thorpe-Ziegler cyclization have been reported. This operationally simple protocol offers a rapid access to a library of 3-aminofurans/thiophenes in moderate to good yields.

A transition-metal-free photoinduced radical-mediated α-oxy C−H cyclobutylation reaction of bicyclo[1.1.0]butane (BCB) compounds was described. In this protocol, α-oxy C(sp3)−H motifs including ethers and alcohols were activated via photocatalytic conditions, releasing the ring strain of BCBs and generating 1,3-disubstituted cyclobutanes in 40–80% yields. Control experiments and Stern-Volmer quenching

Arylation of tertiary aryl and alkyl phosphines bearing 2-cyanoethyl group with aryl(mesityl)iodonium triflates under blue light irradiation followed by retro-Michael reaction of the in situ generated quaternary phosphonium salts initiated by DBU represent a novel efficient and general method for the preparation of distinctly substituted tertiary arylphosphines. An operationally simple, one-pot protocol

Herein, we report a visible-light-induced [2+2+1] dearomative cascade cyclization of indole/furan alkynes with NaHSO3, providing an array of diverse highly strained sulfonyl polycycles. Compared to our previous work, this method does not require the use of additional sacrificial oxidants and have wider reaction scope. Preliminary mechanistic studies suggest that the indole moiety initiated the reaction

A metal- and solvent-free strategy for the preparation of maleimide-fused carbazoles has been developed. This protocol started from 2-(indol-3-yl)cyclohexanones and maleimides, providing various maleimide-fused carbazoles in 45–90% yields. The present approach was catalyzed by trimethylsulfoxonium iodide and involved a cascade of oxidation, [4+2] annulation, and dehydrogenative aromatization. Moreover

This review highlights the allylic C−H alkylation of alkenes (AAH) with nucleophiles under Pd0 or PdII catalysis and achiral or chiral conditions. The η3-allylpalladium intermediates of these reactions are formed from the cleavage of an allylic hydrogen which becomes a leaving group, like the acetate moiety of allyl acetates during the classical Tsuji-Trost procedure. Most of these cross-dehydrogenative-couplings