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Precise control of selective alkene functionalization is a continuing challenge in the chemical community. In this study, we develop a substitution-controlled regiodivergent thioetherification of di- or trisubstituted alkenes using 10 mol% tris(pentafluorophenyl)borane [B(C6F5)3] as a catalyst and N-thiosuccinimide as a sulfenylating reagent. This metal-free borane catalyzed C-S bond forming method is utilized for a Csp2-H sulfenylation reaction to synthesize an array of diphenylvinylsulfide derivatives with good to excellent yields (25 examples, up to 91% yield). Some of the products exhibit aggregation-induced emission luminogen properties used in organic light-emitting diodes (OLEDs), chemical sensors, and biological imaging units. Depending upon the starting alkene, Csp3-S sulfenylation products could also be generated regioselectively. A variety of allylic thioethers from α-alkyl substituted styrenes were isolable in good yields and selectivities (14 examples, up to 67% yield). The DFT-supported mechanistic study confirms that the reaction proceeds via a thiiranium ion intermediate, where the regioselectivity and product formation are determined by the alkene substituents which influences the activation barriers and energy profiles. Diphenylvinylsulfide derivatives can also be efficiently transformed into a range of synthetically valuable compounds, including vinyl sulfoxides, vinyl sulfones, and vinyl sulfoximines., (© 2024 Wiley‐VCH GmbH.)

A two-step formal (4 + 1) annulation-dehydration reaction offers a convenient route to C2-arylated indoles and benzofurans. This reaction exploits the bifunctional reactivity of electron-deficient benzyl chlorides with N -sulfonyl-2-aminobenzaldehydes or salicylaldehyde derivatives. The reaction tolerates both electron-withdrawing and donating groups on the substituted aldehydes, as well as variation of electron-withdrawing groups at the para position of the benzyl chloride reagent. This work also identifies interesting byproducts resulting from the self-reaction of these benzyl chlorides under basic conditions.

Diverse reactivity of the bulky tris(trimethylsilyl)silyl substituent [Si(SiMe 3 ) 3 ], also known as the hypersilyl group, was observed for amidinate-supported dichloro- and phenylchloroborane complexes. Treatment of the dichloroborane with potassium tris(trimethylsilyl)silyl led to the activation of the backbone β-carbon center and formation of saturated four-membered heterocyclic chloroboranes R'{Si(SiMe 3 ) 3 }C(NR) 2 BCl [R' = Ph, R = Cy ( 3 ); R' = Ph, R = i Pr ( 6 ); R' = t Bu, R = Cy ( 8 )], whereas the four-membered amidinate hypersilyl-substituted phenyl borane 4 {PhC(NCy) 2 B(Ph)[Si(SiMe 3 ) 3 ]} was observed for the case of an amidinate-supported phenylchloroborane. The highly deshielded 11 B NMR spectroscopic resonance and the distinct difference in the 29 Si NMR spectrum confirmed the presence of a σ-donating hypersilyl effect on compounds 3 , 6 , and 8 . Reaction of 3 with the Lewis acid AlCl 3 led to the formation of complex 11 in which an unusual cleavage of one of the C-N bonds of the amidinate backbone is observed. Nucleophilic substitution at the boron center of saturated chloroborane 3 with phenyllithium generated the phenylborane derivative 12 , whereas the secondary monomeric boron hydride 13 was observed after treatment with alane (AlH 3 ). All compounds ( 2 - 13 ) have been fully characterized by NMR spectroscopy and single-crystal X-ray structure determination studies.

Herein we report the B(C 6 F 5 ) 3 -catalysed nitro-Mannich reaction between nitrones and silyl nitronates, affording silyl-protected α-nitro hydroxylamines with yields up to 99% and diastereoselectivities up to 99 : 1. Crucially, the obtained products can be converted into 1,2-diamines under simple reductive conditions. This work provides a new orthogonal method to the existing routes for the instalment of a nitro moiety under Lewis acid catalysed conditions, and expands the state-of-the-art substrate scope with respect to the silyl nitronates., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)