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A [3+2]/[2+1] domino annulation reaction of cyclohexadienones and α‐aryl vinylsulfonium salts has been reported. A range of cyclopropane fused tricyclic enones bearing four contiguous stereocenters were obtained as a single diastereomer in 44–93% yields. The synthetic utility was demonstrated with the gram‐scale reactions and further transformations of the products. [ABSTRACT FROM AUTHOR]

The domino annulation reactions of o‐aminotrifluoroacetophenone derivatives and MBH carbonates enabled by PPh3 have been reported, which provide a series of tetrahydrofuro[3,2‐b]indolines containing a CF3‐substituted tetrasubstituted carbon stereocenters in yields of 74 to 95% and >20:1 dr. In this process, MBH carbonates were used as C1/C3 synthons. The MTT assay shows that the products exhibit the activity of inhibitory effect on proliferation on Hela cancer cell line. [ABSTRACT FROM AUTHOR]

The transmetalation triggered rhodium‐catalyzed C−H bond activation and tandem annulation of 2‐biphenylboronic acids with sulfoxonium ylides or iodonium ylides has been developed. Various products of phenanthrenes were constructed under redox‐neutral conditions in 34–86% yields. Several mechanism exploration experiments and derivatization reactions were conducted in sequence to gain a deeper understanding of the process and the potential of this transformation. It offers an alternative approach for the synthesis of phenanthrene derivatives. [ABSTRACT FROM AUTHOR]

The DBU-promoted three-component cascade annulation of 3-oxo-3-phenylpropanenitriles, (E)-chalcones and elemental selenium has been proposed for the synthesis of tetrasubstituted selenophenes. Preliminary mechanism explorations and photochemical performance studies of selenophenes have also been conducted. This protocol possesses some advantages over traditional methods for synthesizing selenophenes in terms of readily available and inexpensive substrates, metal catalyst-free, simple and easy to operate reaction conditions, and step and atom economy. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed intermolecular dearomative formal [4+2] annulation of phenols with propargyl electrophiles is reported, enabling substituent‐controlled regiodivergent synthesis of a wide range of skeletally diverse spirocyclohexadienones with good yields. The regiodivergence could be precisely controlled by adjusting the steric hindrance of O‐ and N‐substituents from binucleophilic substrates, where substrates with an O‐nucleophilic site were converted into spiro[chromane‐4,1′‐cyclohexane]‐2′,5′‐dien‐4′‐ones with complete regioselectivity and (Z)‐selectivity, whereas N‐nucleophiles enabled a different regiodivergent process to access spiro[cyclohexane‐1,4′‐quinoline]‐2,5‐dien‐4‐ones. [ABSTRACT FROM AUTHOR]

Functionalized benzosultams are an essential class of structural motif found in various biologically active molecules. The synthesis of spirocyclic benzosultams from N-sulfonyl ketimine and alkylidenecyclopropanes (ACPs) under the catalysis of Rh(III) has been developed. This transformation enables the formation of two C–C bonds and a double bond with high E-selectivity through C–H and C–C bond activation. This reaction proceeded smoothly with excellent regioselectivity, high efficiency, and tolerance for various functional groups. [ABSTRACT FROM AUTHOR]

The rhodium(iii)-catalyzed intramolecular annulation of alkyne-tethered 3-(indol-3-yl)-3-oxopropanenitriles for the synthesis of fused carbazole scaffolds via C–H activation has been developed. A series of six-, seven-, and eight-membered hydroazepino[3,2,1-jk]carbazoles were achieved. This reaction proceeded under mild reaction conditions and with a broad substrate scope. The reaction involved sequential cleavage of C(sp2)–H/C(sp3)–H bonds and annulation with the tethered alkyne. [ABSTRACT FROM AUTHOR]