Regioselective Formal Hydroamination of Styrenes with 1-Phenyl-1H-tetrazole-5-thiol

C(sp3)-H (N-Phenyltetrazole)thiolation as an Enabling Tool for Molecular Diversification

Methods enabling the broad diversification of C(sp3)-H bonds from a common intermediate are especially valuable in chemical synthesis. Herein, we report a site-selective (N-phenyltetrazole)thiolation of aliphatic and (hetero)benzylic C(sp3)-H bonds using a commercially available disulfide to access N-phenyltetrazole thioethers. The thioether products are readily elaborated in diverse fragment couplings for C-C, C-O, or C-N construction. The C-H functionalization proceeds via a radical-chain pathway involving hydrogen atom transfer by the electron-poor N-phenyltetrazolethiyl radical. Hexafluoroisopropanol was found to be essential to reactions involving aliphatic C(sp3)-H thiolation, with computational analysis consistent with dual hydrogen bonding of the N-phenyltetrazolethiyl radical imparting increased radical electrophilicity to facilitate the hydrogen atom transfer. Substrate is limiting reagent in all cases, and the reaction displays an exceptional functional group tolerance well suited to applications in late-stage diversification.

Visible-Light-Induced Organophotocatalytic Difunctionallization: Open-Air Hydroxysulfurization of Aryl Alkenes with Aryl Thiols

Herein, we report a regioselective visible-light-induced organophotoredox catalytic difunctionalization method to prepare β-hydroxysulfides using aryl alkenes and aryl thiols as substrates. The reaction provides a wide substrate scope of aryl alkenes (from simple styrene to complex bioactive compounds) and aryl thiols (from diverse heteroaromatic thiols to nonheteroaromatic thiols) (total 45 examples, up to 88% yield). Based on the combined experimental and computational studies, we demonstrate that in situ generated hydroperoxyl radicals from O₂ in air react with benzylic radicals, which restrains the reaction between benzylic radicals and the acidic form of thiols in a classical thiol-ene radical reaction. We show that difunctionalization is possible due to the choice of bases, diluted substrate concentrations, increment in catalyst loading, and selection of suitable aryl thiols under aerobic conditions. Considering the biological importance of heteroaromatic thiols and the lack of methods to install them, our approach offers a platform to derive various β-hydroxysulfides that contain aromatic elements.

Crystal structure of bis(2,3-diphenyltetrazolidine-5-thione-κ1 S)-(nitrato-κ1 O)-(nitrato-κ2 O,O′)lead(II), C26H20N10O6S2Pb

C26H20N10O6S2Pb, triclinic, P1̄ (no. 2), a = 9.3480(19) Å, b = 12.985(3) Å, c = 14.278(3) Å, α = 113.14(3)°, β = 92.05(3)°, γ = 102.75(3)°, V = 1539.8(7) Å3, Z = 2, R gt(F) = 0.0336, wR ref(F 2) = 0.0874, T = 293.0 K.

Iodine-Catalyzed Chemoselective Hydroamination Reaction Using 5-Mercaptotetrazoles Derivatives

Metal-free chemoselective hydroamination of styrene derivatives has been achieved with high chemoselectivity over sulfenylation of 1H-tetrazole-5-thiol using a catalytic amount of iodine. The scope of this methodology has been extended for the hydroamination of α-substituted styrene derivatives. This reaction involves a single-step C-N-bond formation under atom economical process. This eco-friendly method uses readily available and inexpensive iodine in a catalytic amount.

Titanium complexes supported by imidazo[1,5-a]pyridine-containing pyrrolyl ligand as catalysts for hydroamination and polymerization reactions, and as an antitumor reagent

The syntheses, structures, catalytic properties and antitumor activities of three titanium complexes supported by an imidazo[1,5-a]pyridine-containing pyrrolyl ligand are reported.