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Comprehensive Summary: A copper‐catalyzed cyanation/diarylmethylation of formamides has been developed for the synthesis of α‐cyano functionalized tetra‐substituted olefins by utilizing para‐quinone methides (p‐QMs) and trimethylcyanosilane as functionalization sources. Various kinds of p‐QMs and formamides are well tolerated, delivering the desired products with 72%—94% yields, demonstrating broad functional group tolerance. Notably, the reaction does not require noble metals and proceeds regioselectively under mild conditions. Based on step‐by‐step control experiments, Hammett studies and DFT calculation, a plausible mechanism is proposed. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The difunctionalization of bicyclo[1.1.0]butanes is an under‐explored transformation that accesses to moieties that are otherwise difficult to prepare. Herein, a new oxidative radical alkylarylation of N‐aryl bicyclobutyl amides with C(sp3)−H feedstocks is achieved in an atom‐economic and photocatalyst‐ and light‐free manner. This protocol follows a sequential C(sp3)–H/C(sp2)–H functionalization, providing an efficient route for diversity‐oriented synthesis of functionalized 3‐spirocyclobutyl oxindoles. In particular, a wide range of C(sp3)−H feedstocks, including ether, alcohol, amine, thioether, polychlorinated methane, silane, acetone, acetonitrile, toluene, and alkane are all suitable for the C(sp3)−H functionalization, demonstrating the broad applicability of this transformation. [ABSTRACT FROM AUTHOR]

A halide-free and metal-free strategy for the construction of C–S/Se–P(O) bonds through a three-component reaction of allylic alcohols, P(O)H compounds, and elemental sulfur/selenium is reported. This protocol eliminates the requirement for using toxic, odorous and moisture-sensitive starting materials, as well as the need for pre-functionalization of substrates. Moreover, this transformation demonstrates high compatibility with various allylic alcohols and P(O)H compounds at a strict ratio of 1 : 1 : 1. Based on controlled experiments, a reaction mechanism involving an allyl carbocation was proposed. [ABSTRACT FROM AUTHOR]

A new radical relay approach for the efficient construction of alkylsulfonated indolo[2,1-a]isoquinoline-6(5H)-ones in moderate to good yields under mild conditions via SO2 insertion/Smiles rearrangement/intramolecular cyclization is developed. This approach utilizes 4-alkyl substituted Hantzsch esters as alkyl radical sources and further undergoes in situ SO2 insertion to obtain alkylsulfonyl radical species, which avoids the use of unstable alkyl sulfonyl chlorides and highly toxic sulfonyl hydrazides. Additionally, this method for the direct assembly of alkylsulfonated polycyclic molecule skeletons displays high chemical selectivity, broad substrate scope, and step-economy. [ABSTRACT FROM AUTHOR]

A direct visible‐light‐promoted radical‐triggered tandem cyclization of 1,7‐diene systems with cyclic sulfonium salts by using copper(I)‐based complexes as photoredox catalyst is developed. With this approach, a variety of sulfur‐containing polycyclic derivatives are prepared through alkylation/6‐exo‐trig cyclization/5‐exo‐trig cyclization of 1,7‐diene systems under mild conditions. In addition, the photoinduced copper‐catalyzed ring‐opening of cyclic sulfonium salts provides the alkyl radical intermediates, which prefers addition to the C−C double bond that connected to the aromatic ring rather than the electron‐deficient vinyl in 1,7‐dienes. Moreover, oxidation of the desired sulfur‐containing polycyclic products provides a strategy for the preparation of remote nitrogen‐fused polycyclic substituted sulfoxide or sulfone‐containing derivatives. [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]