The C–H functionalization of enamines has attracted much attention over the past few years; however, heteroarylation still remains rare.

The elaboration of step-economy and catalytic approaches for accessing diverse fluorinated heterocyclics is highly desirable. Described herein a radical-polar crossover enabled three-component cyclization to polysubstituted fluoropyrazoles by using CF2Br2 as novel C1F1 synthon. Mechanistic experiments revealed that the in situ generation reactive intermediate gem-difluorovinylimine ion key this transformation. This protocol unlocks reactivity adds significant synthetic values fluorine chemistry.

Herein, we present a practical strategy for the direct construction of structurally diverse trifluoromethyl carbinol-containing compounds, especially CF3-substituted tertiary alcohol with chromone derivatives from easily available o-hydroxyaryl enaminones and trifluoroacetaldehyde/ketone under metal-free conditions. This reaction features broad substrate scope good yields is scaled up. Notably, one-pot in two-steps obtained products amidines also developed to provide series multi-substituted...

Switchable multicomponent reactions have been attractive tools for the construction of compound libraries with skeleton diversity and complexity by slightly changing reaction conditions. Described herein is a regioselectivity-switchable formal [1 + 2 2] cycloaddition from difluoroalkyl compounds, enaminones, RNHNH2, ultimately using 1-methylindazol-3-amine as traceless mediator to switch inherent regioselectivity 1,3,4-trisubstituted pyrazole formation 1,4,5-trisubstituted pyrazoles....

A highly efficient molecular iodine mediated Radziszewski-type reaction of methyl ketones, anilines, and tosylmethyl isocyanide has been developed. This protocol represents an elegant fragment assembly imidazoles via a formal [2 + 1 1] annulation. It is the first example where ketones serve as α-dicarbonyl compounds aldehydes in reactions.

An unprecedented direct dual C–H bond functionalization of unprotected anilines and methyl ketones has been demonstrated. It is the first example iodine-promoted highly chemo- site-selective oxidative C–H/C–H cross-coupling to furnish C4-dicarbonylation in moderate good yields. Moreover, coproduct HI acted as a catalyst reaction. The salient feature this approach rather than N–H anilines.

The first synthesis of 2,3-diaroyl quinolines via a formal [3 + 2 1] cycloaddition enaminones, aryl methyl ketones, and amines is disclosed. This reaction efficiently affords 1,4-dicarbonyl scaffold, which useful building block for constructing complex fused heterocycles. Furthermore, the scaffold has been used directly to prepare pyridazino[4,5-b]quinoline skeletons in one-pot.

Here we develop a novel visible-light-driven three-component cyclization by trapping an 1,3-vinylimine ion intermediate for the direct synthesis of pyrimido[1,2-b]indazole derivatives from bromodifluoroacetic acid derivatives, enaminones, and 3-aminoindazoles under mild conditions. Notably, robust methodology provides valuable opportunity introduction aliphatic substituents enables good compatibility complex bioactive molecules. Furthermore, this is first example photoinduced multicomponent...

A novel and efficient three-component reaction with two C–N bonds one C–F bond formation has been reported, which provides a straightforward route to variety of fluorinated pyrimido[1,2-b]indazole derivatives. This transformation the advantage excellent functional group compatibility, including aliphatic aromatic substituents enaminones. Moreover, metal additives are not necessary for this reaction, is great significance synthesis application heterocycles.

Comprehensive Summary Catalytic and green strategies for the synthesis of privileged scaffolds are synthetically appealing. We now report a radical‐polar crossover (RPC)‐enabled three‐component cyclization bromodifluoroalkyls with enaminones 6‐aminouraciles via visible‐light‐induced domino cyclization. The reaction exhibited broad substrate scope (> 40 examples) including complex molecules, which highlighted utility this strategy construction library bioactive analogs.

Comprehensive Summary The development of switchable solvent‐free multicomponent reactions to build high‐value‐added products is an important demand for organic synthesis. Herein, we detailed the successful implementation a strategy construction diverse 4‐fluoroalkyl‐1,4‐dihydropyrimidines and 4‐fluoroalkyl‐pyrimidines via solvent/additive‐free [3 + 2 1] annulation, starting from readily available enamines, trifluoroacetaldehyde hydrate or 1‐ethoxy‐2,2‐difluoroethanol amidines hydrochloride....

An efficient and practical de novo synthesis of pyrrole-2-carbaldehyde skeletons featuring oxidative annulation Csp3–H to C═O oxidation is presented, exemplified by the preparation derivatives from aryl methyl ketones, arylamines, acetoacetate esters. Preliminary mechanistic investigations indicate that aldehyde oxygen atom originates oxygen. Moreover, developed scalable approach provides a distinct advantage over traditional functionalization C–H moieties, avoiding use stoichiometric...

An I2-promoted domino bicyclization approach via multiple sequential C-H functionalization was serendipitously discovered for the synthesis of 1,2-fused oxindoles from methyl ketones and anilines. This optimized, resulting in a concise atom-economical one-pot construction anilines rather than using preexisting indolin-3-ones or indoles. Mechanistic studies revealed that key step involved an oxidative cross-coupling between situ generated phenylglyoxal α,α-diaminoketone.

A synergistic I2/amine promoted formal [4 + 2] cycloaddition of methyl ketones, arylamines, and aryl(alkyl)acetaldehydes as alkene surrogates has been established. This protocol allowed the modular synthesis various 2-acyl-3-aryl(alkyl)quinolines, rather than 2,4-substituted quinolines. Notably, arylamines not only participated reactants in this reaction but also acted indispensable catalysts to promote enamine formation. Moreover, mechanistic investigation suggested that occurred via an...

A highly efficient I2-promoted formal [4 + 2] cycloaddition has been developed for the synthesis of 2-acylquinolines from methyl ketones and arylamines using 1,4-dithane-2,5-diol as an ethylene surrogate. Moreover, investigation mechanism suggested that this reaction occurred via iodination/Kornblum oxidation/Povarov/aromatization sequence. It is noteworthy arylamine substrate also played important role in promoting reaction.

We report an I2/FeCl3-co-promoted formal [2 + 2+1] annulation of aryl methyl ketones, 2-aminobenzyl alcohols, and p-toluenesulfonylmethyl isocyanide (TosMIC) by neighboring group (-CH2OH) assistance. This is a novel example using the Van Leusen reagent as unique C1N1 "two-atom synthon" in synthesis imidazoles. Preliminary mechanism studies showed that TsCH2NH2 might be key intermediate this reaction. Furthermore, reaction not only unlocks strategy for imidazole synthesis, but also exploits...

Herein, a photoinitiated radical relay reaction of quinoxalin-2(1H)-ones, with acyloxy nitroso compounds as source radicals, is described. Although the C-H functionalization quinoxalin-2(1H)-ones has been investigated, its difunctionalization, simultaneous construction C-C and N-N bonds directly via reaction, rarely reported. Moreover, obtained products underwent sequential reactions to access C7-NO2 under mild conditions.

Abstract A photoinduced multicomponent reaction of arylamines, enaminones and difluorobromoacetates for the synthesis 2,3‐difunctionalized quinolines is reported. This strategy features broad functional groups tolerance wide substrate scopes that enables further synthetic applications obtained products. Mechanistic studies reveal intermolecular [3+3] cyclization between in‐situ generated 1,3‐vinylimine ions arylamines key step in this transformation. magnified image

The development of different concept approaches and user-friendly carbonyl surrogates for aminocarbonylation is highly desirable. Herein, we report the photocatalytic enaminones with easily available o-aminobenzamides CF2Br2 through an oxygen migration-defluorination strategy. reaction features switchable transformation construction carbamoyl-substituted enol products allows expedient synthesis fully substituted maleimides under mild conditions.

A novel iodine-promoted oxidative cross-coupling/cyclization of 2-(pyridin-2-yl)acetate derivatives and methyl ketones via the cleavage multiple Csp3-H bonds has been developed, which also achieved efficient a C-C bond in derivatives. This protocol represents an elegant molecular fragment assembly diverse 3-(pyridin-2-yl)indolizines formal [3 + 1 1] annulation. Notably, pyridine serve two pivotal roles to provide fragments construct 3-(pyridin-2-yl)indolizine skeletons, rather than single...

An I₂-promoted formal [3+2] cycloaddition for access to oxazoles has been demonstrated. The salient feature of this approach is unconventional 2,5-disubstituted oxazole formation from isocyanides and ketones rather than 4,5-substituted oxazoline.

An efficient I2/CuCl2-promoted one-pot three-component strategy for the construction of 1,2,3-thiadiazoles from aliphatic- or aromatic-substituted methyl ketones, p-toluenesulfonyl hydrazide, and potassium thiocyanate has been developed. Simple commercially available starting materials, a broad substrate scope, excellent functional group tolerability make this practical applications. Furthermore, 1,2,3-thiadiazole synthesis was realized by using as an odorless sulfur source.

The first synthesis of arylquinazolinones has been disclosed via the consecutive oxidative cyclization/ring-opening anilines and methyl ketones. This transformation is characterized by splitting ketone as acyl C1 sources through C(CO)–C(sp3) bond cleavage, using DMSO a source C–S which expands use ketones valuable building blocks enriches library preparation quinazolinones. Moreover, preliminary mechanistic studies indicate that this multicomponent reaction underwent sequence.

The iodine-catalyzed catalytic formal [3 + 3 1] cycloaddition for the preparation of a seven-membered O-heterocyclic ring is presented, which an achievement methyl and carbonyl group reactivity 3-methyl-5-pyrazolones to forge Csp3-O bond. This novel protocol provides straightforward efficient access structurally diverse fused O-heterocycles through iodination/Kornblum oxidation/oxidative coupling/C-O bond formation cascade reaction. approach demonstrates unprecedented concurrent realization...