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A general method for ortho-functionalization of pentafluorosulfanyl arenes has been developed. ortho-Lithiation with lithium tetramethylpiperidide at −60 °C in the presence of silicon, germanium, and tin electrophiles affords trapped products in moderate to high yields. Precise temperature regimes and the presence of electrophiles during lithiation are important for successful reactions, since the pentafluorosulfanyl group acts as a competent leaving group at temperatures above −40 °C. Fluoro, bromo, iodo, enolizable keto, cyano, ester, amide, and unsubstituted amino functionalities are compatible with the reaction conditions. Conversion of 2-dimethylsilylpentafluorosulfanyl benzene to 2-halosubstituted derivatives, useful as starting materials in cross-coupling chemistry, was also demonstrated. [ABSTRACT FROM AUTHOR]

N-Iminopyridinium ylides are competent monodentate directing groups for cobalt-catalysed annulation of sp2 C–H bonds with internal alkynes. The pyridine moiety in the ylide serves as an internal oxidant and is cleaved during the reaction. The annulation reactions possess excellent compatibility with heterocyclic substrates, tolerating furan, thiophene, pyridine, pyrrole, pyrazole, and indole functionalities. [ABSTRACT FROM AUTHOR]

Lithium 1,1-diadamantylamide (LDAM) base-promoted insertion of arynes into disulfide S–S bonds is described. After generation of arynes from readily available aryl halides and triflates, reactions with diaryl and diisopropyl disulfides afford the insertion products in moderate to excellent yields. Use of 1-cyclohexenyl triflate gave an excellent yield of 1,2-bis(phenylthio)cyclohexene. [ABSTRACT FROM AUTHOR]

Creating stimuli-responsive materials with switchable solid-state luminescence remains a challenge. We report that the solvation of a novel organic fluorophore can be utilized to prepare such a material, which emits in the blue (442–446 nm) region when wet and in the green (497–503 nm) region when dry. [ABSTRACT FROM AUTHOR]

We report a method for palladium-catalysed chain-running isomerization of terminal and internal alkenes. Using an air-stable 2,9-dimethylphenanthroline-palladium catalyst in combination with NaBAr4 promoter, olefins are converted to the most stable double bond isomer at −30 to 20 °C. Silyl enol ethers are readily formed from silylated allylic alcohols. Fluorinated substituents are compatible with the reaction conditions, allowing the synthesis of fluoroenolates. Catalyst loading as low as 0.05% can be employed on a gram scale. [ABSTRACT FROM AUTHOR]

We report a method for cobalt-catalyzed, aminoquinoline-directed sp2 C–H bond carbonylation of sulfonamides. The reactions proceed in a dichloroethane solvent, and employ diisopropyl azodicarboxylate as a carbon monoxide source, Mn(OAc)2 as a cooxidant and potassium pivalate as a base. Halogen, ester, and amide functionalities are compatible with the reaction conditions. This method allows for a short and efficient synthesis of saccharin derivatives. [ABSTRACT FROM AUTHOR]

Three perfluorinated Cu-based metal–organic frameworks (MOFs) were prepared starting from extensively fluorinated biphenyl-based ligands accessed via C–H functionalization. These new materials are highly hydrophobic: with water contact angles of up to 151 ± 1°, they are among the most water-repellent MOFs ever reported. [ABSTRACT FROM AUTHOR]

N-Iminopyridinium ylides are competent monodentate directing groups for cobalt-catalysed annulation of sp2 C-H bonds with internal alkynes. The pyridine moiety in the ylide serves as an internal oxidant and is cleaved during the reaction. The annulation reactions possess excellent compatibility with heterocyclic substrates, tolerating furan, thiophene, pyridine, pyrrole, pyrazole, and indole functionalities.

We report a method for cobalt-catalyzed, aminoquinoline-directed sp 2 C-H bond carbonylation of sulfonamides. The reactions proceed in a dichloroethane solvent, and employ diisopropyl azodicarboxylate as a carbon monoxide source, Mn(OAc) 2 as a cooxidant and potassium pivalate as a base. Halogen, ester, and amide functionalities are compatible with the reaction conditions. This method allows for a short and efficient synthesis of saccharin derivatives.

Aminoquinoline-directed, palladium-catalyzed sp 3 C-H bond arylation in phosphonamidates and phosphinic amides is reported. The reaction employs Pd(OAc) 2 as a catalyst at 10 mol% loading and cesium phosphate or potassium carbonate as a base in 1,2-dichlorobenzene as a solvent. The directing group can be removed under basic conditions to afford phosphonic acid esters. The chemistry described here is the first example of unactivated sp 3 C-H bond arylation by using a phosphorus-containing directing group.

Two reactions of phenols with arynes have been developed. If LiTMP base is employed, arynes generated from aryl chlorides react with phenols to form helicenes. o -Arylation of phenols can be achieved by employing t BuONa base in the presence of AgOAc. Direct arylation of binol was achieved leading to the shortest pathway to o,o'-diarylbinols.

A highly regioselective, one-pot sequential iodination-copper-catalyzed cross-coupling of arene C-H bonds has been developed affording an efficient method for biaryl synthesis.