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Comprehensive Summary: A novel visible‐light‐induced radical cascade 6‐endo cyclization of dienes (N‐(2‐vinylphenyl)acryl amides) is developed utilizing α‐carbonyl bromides as alkyl reagents. This approach affords an efficient way for synthesizing six‐membered benzo‐fused lactam derivatives with chemo‐ and regio‐selectivity and good functional group tolerance. Primary, secondary, and tertiary bromides are well‐compatible with this cascade cyclization reaction. [ABSTRACT FROM AUTHOR]

A four‐component reaction of N‐arylpropiolamides, Hantzsch esters, Na2S2O5 and water via a radical cascade cyclization process with the insertion of sulfur dioxide mediated by K2S2O8 is reported. A series of alkylsulfonated spiro[4,5] trienones are prepared up to 86% yield with a good functional group tolerance and substrate applicability. Preliminary mechanism experiments indicate that carbonyl oxygen of spiro[4,5] trienones originated from water. [ABSTRACT FROM AUTHOR]

A novel strategy of visible‐light photoredox catalysis ipso‐annulation of activated alkynes with polychloroalkanes for the synthesis of 3‐polychloroalkyl spiro[4,5]trienones, which used 4‐methoxybenzenediazonium tetrafluoroborate salt as a hydrogen atom transfer reagent, is described. This polychloroalkylation/ spirocyclization of alkynes offers a widely range of 3‐polychloroalkyl‐spiro[4,5]trienone derivatives in high yields with a broad substrate scope via selective C(sp3)‐H homolytic cleavage. The results of controlled experiments showed that this method involves a radical process. The polyhaloalkyl radical species generated from intermolecular hydrogen atom transfer (HAT) between aryl radical and polychloroalkanes. [ABSTRACT FROM AUTHOR]

A simple and efficient oxidative‐promoted radical cascade annulation of ynone derivatives with ketones for the construction of a series of oxoalkyl‐substituted indenones in moderate to good yields is described. The control experiment results indicate that the oxidative acetmethylation/arylation of ynone derivatives involves a radical cascade cyclization process. This is an operationally simple and efficient protocol which will be attractive in organic synthesis chemistry. [ABSTRACT FROM AUTHOR]

An oxidative sulfonylation/cyclisation of N‐propargylindoles with Hantzsch esters through sulfur dioxide insertion has been developed. The method uses Na2S2O5 as sulfur dioxide source along with 4‐alkyl‐substituted Hantzsch esters as radical precursors for accessing sulfonyl radicals, and allows for the synthesis of 2‐sulfonated 9H‐pyrrolo[1,2‐a]indoles. [ABSTRACT FROM AUTHOR]

A new photoinduced acylation/arylation of N‐(arylsulfonyl)acrylamide with acyl oxime esters through a nitrogen‐centered radical protocol has been disclosed for efficient preparation of functionalized indolin‐2‐ones, which proceeds through a cascade acyl radical addition of carbon‐carbon double bond, aryl migration, desulfonylation, and intramolecular cyclization sequence. This redox‐neutral strategy features excellent selectivity, good substituent tolerance, and wide substrate scope. [ABSTRACT FROM AUTHOR]

A nitrogen‐centered radical strategy for the preparation of 3‐acylated spiro[4,5]trienones via visible‐light‐mediated acylation/ipso‐cyclization of alkynes with acyl oxime esters is reported. The alkyl‐ and aryl‐substituted acyl radicals, which generate from the cleavage of carbon‐carbon σ‐bonds in acyl oxime esters via nitrogen‐centered radical pathway, attack the carbon‐carbon triple bonds in propiolamides and then undergo ipso‐cyclization. This method provides a way for the construction of 3‐acyl‐substituted spiro[4,5]trienones, which can introduce aryl‐ or alkyl‐substituted acyl into spiro[4,5]trienone skeletons. [ABSTRACT FROM AUTHOR]

Iron‐mediated radical cyanoalkylsulfonylation/arylation of active olefins with cycloketone oxime derivatives via cleavage of C−C single bond and insertion of SO2 is developed for the preparation of cyanoalkylsulfonylated oxindoles. This difunctionalization of carbon−carbon double bond via a radical pathway involves cyclobutanone oxime ester fragmentation, sulfonyl radical generation and radical addition/5‐exo cyclization. The methodology displays good functional group tolerance and does not require any external bases or oxidants. [ABSTRACT FROM AUTHOR]

An efficient novel visible-light photoredox-catalyzed dual carbon–carbon bond cleavage of methylenecyclopropanes and cycloketone oximes for the synthesis of 2-cyanoalkylsulfonated 3,4-dihydronaphthalenes through the insertion of sulfur dioxide is established. This dual cleavage of carbon–carbon bonds involves a radical pathway and goes through a sequence of iminyl radical formation, carbon–carbon bond cleavage, sulfur dioxide insertion, sulfonyl radical addition, another carbon–carbon bond cleavage, and intramolecular cyclization. [ABSTRACT FROM AUTHOR]

A novel visible-light promoted sulfonylation/ipso-cyclization of N-arylpropiolamides with arylamines and DABCO·(SO2)2 to synthesize various sulfonated spiro[4,5]trienones is reported. This sulfonylation/ipso-cyclization reaction proceeds via a radical process and undergoes arylsulfonyl radical formation, sulfonylation, and ipso-cyclization. The experimental results indicate that H2O provides an oxygen atom for the construction of the carbonyl group. [ABSTRACT FROM AUTHOR]

Without using any transitionmetal and base, an eco‐friendly, practical and economical protocol has been established for the one‐pot synthesis of diverse (E)‐1‐phenyl‐4‐sulfonylbut‐1‐enes from easily accessible starting materials. This strategy features a wide substrate scope, tolerates a broad range of functional groups, employs a less expensive oxidant, is operationally simple, and can be easily scaled‐up. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The 1,2-alkylarylation occurs under transition-metal-free and oxidant-free conditions. • A variety of important 5- oxo -pentanenitriles were obtained. • The results proved that the cleavage of C(sp3)–H bond of acetonitrile is a rate-limiting step. Abstract An efficient visible-light-induced difunctionalization of alkenes with a -C(sp3)–H bonds of nitriles is described for the constructing of diverse 5- oxo -pentanenitriles under transition-metal-free conditions. This protocol proceeds via the functionalization of C(sp3)–H bond and radical addition/intramolecular 1,2-aryl migration processes, which features a wide scope of substituted α , α -diaryl allylic alcohols. The results of kinetic isotope experiments show that the cleavage of C(sp3)–H bond of acetonitriles is a rate-limiting step. [ABSTRACT FROM AUTHOR]

A new visible-light-mediated radical cyclization of alkynoates with acyl chlorides is described for the one-pot construction of diverse 3-acylcoumarins with high efficiency and selectivity. This method is successful by sequential difunctionalization of an alkynes C C triple bond with the C Cl bonds of acyl chloride and aromatic C(sp 2 ) H bonds. The cyclization is proposed to simultaneously form two new carbon–carbon bonds, and involves radical acylation, 5-exo-trig cyclization, and ester migration. [ABSTRACT FROM AUTHOR]

Cu(II)-modified nitrogen-rich covalent organic polymer (Cu/N-COP-1) was fabricated and employed to catalyze the cross-dehydrogenative ortho-aminomethylation of phenols. The Cu/N-COP-1 catalyst displayed excellent catalytic activity under mild conditions without any ligand. Various substituted phenols and N , N -dimethylanilines were successfully converted to the corresponding products. Moreover, the catalyst can be readily reused for at least five consecutive runs without obvious loss of catalytic activity. This can be attributed to the interaction between the nitrogen-containing group of the covalent organic polymer and Cu species, which makes Cu species steadily immobilized on the surface of polymer. [Display omitted] • The active site can be steadily immobilized on the surface of covalent organic polymer. • The catalyst shows excellent catalytic activity under mild conditions without any ligands. • The reaction is wider universality to the substrate. • The catalyst can be recycled for at least five consecutive runs. [ABSTRACT FROM AUTHOR]