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Herein, a novel chelation-assisted C-H arylation reaction of benzo[h]quinoline is described. This transformation, using [RuCl

A divergent reaction of isocyanides with o-bromobenzaldehydes for the synthesis of isoindolinone-derived ketenimines and lactams was disclosed. The reaction features readily available reactants, relatively mild conditions, and high yields of products. Ketenimines could be applied in further transformations for access to other functional molecules. A mechanism study showed that the palladium-migration/imine-insertion process was the key step in this reaction.

Herein, a novel palladium-catalyzed regioselective diarylation/deamination of homoallylamines is described. During the process, a ubiquitous free amine (NH

It has always been a challenge in free radical chemistry to control site selectivity during the reaction of free radicals with aromatic rings. Herein, we report the site-selective carboxylation of anisoles through the direct reaction of the bromoform radical with a benzene ring at the

A divergent reaction of isocyanides with

A Co-catalyzed cyclization reaction of isocyanides, azides, and amines to access quinazoline derivatives was described. This protocol features a high atom economy, mild reaction conditions, excellent yields, and a broad substrate scope. This cascade reaction involved three or four C-N bonds and the formation of one or two rings. The quinazolin-4(H)-imines obtained are proven to be versatile intermediates for further valuable transformations. It was also found that the cobalt catalyst could be isolated from the reaction mixture and reused.

A facile synthesis of N-(carboselenoate) benzimidazolones through metal-free reactions of ortho-diisocyanoarenes with selenosulfonates is reported here. The desired products are obtained in moderate to good yields with good functional group compatibility. The ortho-diisocyanoarenes are applied to the construction of 2-benzimidazolone derivatives for the first time.

A new synthesis of quindoline derivatives promoted by Mn(III)/Brønsted acid via a dehydroxylation/azidation/cyclization cascade of diaryl(1 H-indol-2-yl)methanols with trimethylsilyl azide was developed. The reaction features very effective transformation involving two C(sp

A regioselective rhodium-catalyzed thiolation of N-tosyl acrylamides with readily available disulfides has been developed. Through N-tosylamide-assisted activation of the alkenyl C(sp2)–H bond, a series of (Z)-alkenyl sulfides were constructed in moderate to excellent yields with good tolerance of functional groups. Turnover numbers (TONs) of up to 7100 were obtained utilizing 0.01 mol % RhIII catalyst. In addition, diphenyl diselenide was also successfully applied to this reaction for the construction of (Z)-β-alkenyl selenides under identical conditions.

A Co(II)/Ag(I) synergistically catalyzed three-component reaction of isocyanide with terminal alkyne and water to afford alkynamide derivatives is reported. The insertion of monoisocyanide into the C–H bond of terminal alkynes is an efficient, straightforward, atom-economical route to alkynamides, which are useful synthons in organic synthesis. This synergistic process achieves the cleavage of a C–H bond and the construction of new C–C and C═O bonds under mild conditions through the reaction of Co(II)-activated isocyanides and a Ag(I)-complex-activated terminal alkyne. This reaction has broad substrate versatility and functional group tolerance.

S3•–-mediated [1 + 2 + 2] and [1 + 3 + 1] cycloaddition reactions of aromatic alkynes to give tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives via two C–S bond formations are developed. These two protocols provide new, simple, and straightforward strategies to construct tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives under transition-metal-free conditions. This study also expands the application of S3•– in organic reactions.

A novel and efficient approach for the selenium functionalization of indoles was developed with selenium powder as the selenium source, catalyzed by 2,2,6,6-tetramethylpiperidinooxy (TEMPO) and employing O2 as the green oxidant. This protocol provides a practical route for the synthesis of 3-selenylindole derivatives and has the advantages of readily available starting materials, mild reaction conditions, and a wide scope of substrates. Electron spin-resonance (ESR) studies reveal that the approach involves the formation of nitrogen-centered radicals and selenium radicals via oxidation of in situ generated selenoates.

A Pd-catalyzed insertion and cycloaddition of CO2 and isocyanide into 2-iodoanilines under atmospheric pressure has been developed and affords quinazoline-2,4(1H,3H)-diones through the formation of new C–C, C–O, and C–N bonds under mild conditions. This reaction provides a new and practical method not only for the construction of quinazoline-2,4(1H,3H)-diones but also for the efficient utilization of carbon dioxide.

A novel silver-catalyzed fluorination reaction of carbonyl directed alkynes in the presence of N-fluorobenzenesulfonimide and water with high regioselectivities has been developed. The established protocol provides an alternative method for rapid assembly of α-fluoroketone derivatives under simple and mild reaction conditions. The reaction pathway involves a ring closure and opening process for the construction of new C-O and C-F bonds. In addition, a fluorine-containing indanone was observed through further N-heterocyclic carbene catalyzed intramolecular crossed-benzoin reaction of α-fluoroketone.

A palladium-catalyzed cascade arene/alkyne annulation reaction for the synthesis of fluorene-benzoxazine derivatives is developed. This transformation involves a 6-exo-dig cyclization, a 1,3-oxazine vinylpalladium intermediate, and a C-H bond activation.

A palladium-catalyzed tandem C-Br/C-H functionalization and cyclization of alkenes with organohalides is reported. This reaction provides an operationally simple method for the synthesis of various fluorene, pyrroloindole, and benzoxazine derivatives, which are useful pharmaceutical framework and photoelectronic devices. Two new C-C/O bonds, a quaternary carbon center and a new ring, are simultaneously formed in this one-pot reaction.

A Mn(III) mediated cascade cyclization of new designed multifunctionalized 3-isocyano-[1,1′-biphenyl]-2-carbonitrile with arylboronic acid to construct pyrrolopyridine derivatives is developed. A series of pyrroloporidine compounds have been constructed through the formation of two new C–C bonds and one C–N bond via a radical pathway.

A regioselective rhodium-catalyzed thiolation of N-tosyl acrylamides with readily available disulfides has been developed. Through N-tosylamide-assisted activation of the alkenyl C(sp

A Co(II)/Ag(I) synergistically catalyzed three-component reaction of isocyanide with terminal alkyne and water to afford alkynamide derivatives is reported. The insertion of monoisocyanide into the C-H bond of terminal alkynes is an efficient, straightforward, atom-economical route to alkynamides, which are useful synthons in organic synthesis. This synergistic process achieves the cleavage of a C-H bond and the construction of new C-C and C═O bonds under mild conditions through the reaction of Co(II)-activated isocyanides and a Ag(I)-complex-activated terminal alkyne. This reaction has broad substrate versatility and functional group tolerance.

A novel synthetic approach toward 1,4-disubstituted 1,2,3-triazoles and 1,5-disubstituted 1,2,3-triazoles by aerobic oxidative cycloaddition of α-chlorotosylhydrazone with primary aryl amine has been developed. Significantly, the reaction proceeds smoothly to afford 1,4-disubstituted 1,2,3-triazoles and 1,5-disubstituted 1,2,3-triazoles under catalyst-free, metal-free, azide-free, and peroxide-free conditions.

A Pd-catalyzed insertion and cycloaddition of CO

An efficient I2 (20 mol %)/TBPB mediated oxidative formal [4 + 1] cycloaddition of N-tosylhydrazones with anilines via C-N/N-N bond formation and S-N cleavage has been developed. This protocol represents a simple, general, and efficient approach for the construction of 1,2,3-triazoles under metal-free and azide-free conditions by utilizing a catalytic amount of I2.

An I2/TBHP mediated oxidation of commercially available indoles has been developed, which affords isatins in moderate to good yields.

A multicomponent domino reaction for the chemoselective, catalyst-free synthesis of polysubstituted pyrroles from readily available isocyanides, primary or secondary amines, and gem-diactivated olefins has been developed. Structurally diverse pyrroles were obtained in moderate to good yields under mild conditions.

A novel catalyst-free one-pot tandem reaction for the stereoselective construction of polycyclic spiroindolines was developed. This method offers a straightforward access to structurally diverse polycyclic spiroindoline derivatives in high yields (up to 90%) with excellent levels of diastereoselectivity.

A novel CuI/BF(3)·Et(2)O/O(2)-mediated reaction utilizing ketones and benzylamines for the construction of substituted imidazoles in one step under mild conditions has been demonstrated. This protocol involved the removal of eight hydrogen atoms, the functionalization of four C(sp(3))-H bonds and three new C-N bond formations.

An intriguing new Wacker-type oxidation of alkynes catalyzed by PdBr(2) and CuBr(2) is described, which opens an efficient access to 1,2-diketones using molecular oxygen. Under the optimized conditions, a variety of alkynes, including diarylalkynes, arylalkylalkynes, and dialkylalkynes, were compatible substrates in this transformation. The mechanism of this reaction was preliminarily investigated by control experiments.

A novel palladium-catalyzed formylation of aryl halides with isocyanide in the presence of Et3SiH has been demonstrated, which provides a strategy toward important aldehydes with moderate to excellent yield. The advantage of this reaction includes milder conditions, convenient operation, lower toxicity, and wide functional group tolerance.

A novel and efficient protocol for the creation of 6-amino phenanthridine derivatives by Co(acac)2-catalyzed isocyanide insertion with 2-aryl anilines under an O2 atmosphere via homolytic aromatic substitution (HAS) type C–H functionalization has been developed. This reaction not only proceeds smoothly utilizing O2 as the oxidant but also provides a new approach to construct phenanthridine derivatives utilizing readily available 2-aryl anilines with isocyanides instead of 2-isocyanobiaryls with different radical precursors.

A novel I2/TBHP-mediated direct oxidative diamination reaction of indoles with anilines was developed. The reaction proceeded smoothly under aqueous and open air reaction conditions. This protocol provides a practical synthetic method for the synthesis of Tryptanthrin and the construction of N-C3 linked pyrrolidinoindolines which is the core structure of Psychotrimine.

Multicomponent reactions of acenaphthylene-1,2-dione with diaroylmethanes and electron-rich pyrazol-5-amines have been discovered. A series of new and polyfunctionalized pentacyclic pyrazole-fused naphtho[1,8-fg]isoquinolines were regioselectively synthesized. The reactions were easy to perform simply by mixing three common reactants in AcOH. During these reaction processes, the insertion of active methylene of diaroylmethane into the sp(2)-sp(2) C-C bond of the cyclohexa-2,5-dienone ring was readily achieved and two C-C bonds were cleaved under transition-metal-free conditions.

A chiral indium(III)-PYBOX complex prepared from indium triflate and chiral PYBOX has been discovered to effect high enantioselectivities in the addition of allyltributyl stannane to aldehydes. The allylation of a variety of aromatic, alpha,beta-unsaturated, and aliphatic aldehydes resulted in good yields and high enantioselectivities (up to 94% ee).