Cu-Catalyzed Three-Component Coupling of Aryne, Alkyne, and Benzenesulfonothioate: Modular Synthesis of <i>o</i>‑Alkynyl Arylsulfides

A copper-catalyzed three-component coupling reaction of in situ formed arynes, terminal alkynes, and benzenesulfonothioates is described. This reaction provides an efficient modular synthesis of <i>o</i>-alkynyl arylsulfides from easily available starting materials. This process involves one C–S bond and one C–C bond formation in one pot

Small Titanium Oxo Clusters: Primary Structures of Titanium(IV) in Water

For sol–gel synthesis of titanium oxide, the titanium­(IV) precursors are dissolved in water to form clear solutions. However, the solution status of titanium­(IV) remains unclear. Herein three new and rare types of titanium oxo clusters are isolated from aqueous solutions of TiOSO₄ and TiCl₄ without using organic ligands. Our results indicate that titanium­(IV) is readily hydrolyzed into oxo oligomers even in highly acidic solutions. The present clusters provide precise structural information for future characterization of the solution species and structural evolution of titanium­(IV) in water and, meanwhile, are new molecular materials for photocatalysis

Atom Transfer Radical Addition to Alkynes and Enynes: A Versatile Gold/Photoredox Approach to Thio-Functionalized Vinylsulfones

An efficient intermolecular atom-transfer addition reaction of alkynes via the combination of visible-light photoredox catalysis and gold catalysis has been developed, affording diverse trifluoromethylthio- and difluoromethylthio-functionalized vinylsulfones with high stereoselectivity in good yields. Thiosulfonylation reaction of enyne can also be realized for constructing functionalized carbo- and heterocycles through a radical cascade cyclization process. These reactions proceed through a gold-assisted sulfonyl radical addition pathway

Copper-Catalyzed Oxidative Trifunctionalization of Olefins: An Access to Functionalized β‑Keto Thiosulfones

Aerobic oxidative trifunctionalization of olefins for the synthesis of functionalized β-keto thiosulfones has been described. The transformation proceeds through molecular oxygen activation under copper catalysis and forms the two new C–S bonds in a single operation using mild conditions. A novel Cu-catalyzed sulfonyl radical addition/oxidation/funtionalization relay mechanism was proposed for the discovered reaction

TiO₂ Photocatalytic Cyclization Reactions for the Syntheses of Aryltetralones

This work focuses on a new strategy to overcome the overoxidation in heterogeneous TiO₂ photocatalysis and to realize high-efficiency photosynthesis. We demonstrate that TiO₂ photocatalysis can integrate C–C and CO formation in a tandem manner to achieve efficient oxidative cyclization for the syntheses of aryltetralones. This protocol does not need any additive besides the inexpensive and/or recyclable TiO₂, O₂, and (solar) light. High yields with excellent diastereoselectivities are obtained for a wide scope of electron-rich substrates. Our findings demonstrate that in contrast to the conventional overoxidation, as long as the radical cations possess sufficient reactivity toward nucleophilic addition, single-electron transfer processes in TiO₂ photocatalysis can be developed into a powerful tool to construct C–C bonds and even strained carbon rings

Alkali Halide Cubic Cluster Anions ([Cs₈X₂₇]^19–, X = Cl, Br) Isolated from Water

Herein we report the syntheses and the X-ray structure of [Cs₈X₂₇]^19‑ (X = Cl, Br) clusters, the first binary cluster anions isolated in bulk crystal structures. They were obtained by electrostatic capture and face-directed recognition of the prenucleation [Cs_<i>m</i>Cl_<i>n</i>]^{(<i>n</i>−<i>m</i>)–} clusters from water solutions, using [M₄(OH)₈(OH₂)₁₆]⁸⁺ (M = Zr^IV or Hf^IV) as the counter cations. These compounds have been thoroughly characterized with a variety of techniques including vibrational spectroscopy and superionic conductivity analysis. This work not only provides structural models for a better understanding of the nucleation of binary materials but also shows that magic number binary clusters adopting a cubic lattice structure do form, in agreement with the time-honored theoretical and spectroscopic predictions

Small Titanium Oxo Clusters: Primary Structures of Titanium(IV) in Water

For sol–gel synthesis of titanium oxide, the titanium­(IV) precursors are dissolved in water to form clear solutions. However, the solution status of titanium­(IV) remains unclear. Herein three new and rare types of titanium oxo clusters are isolated from aqueous solutions of TiOSO₄ and TiCl₄ without using organic ligands. Our results indicate that titanium­(IV) is readily hydrolyzed into oxo oligomers even in highly acidic solutions. The present clusters provide precise structural information for future characterization of the solution species and structural evolution of titanium­(IV) in water and, meanwhile, are new molecular materials for photocatalysis

Small Titanium Oxo Clusters: Primary Structures of Titanium(IV) in Water

For sol–gel synthesis of titanium oxide, the titanium­(IV) precursors are dissolved in water to form clear solutions. However, the solution status of titanium­(IV) remains unclear. Herein three new and rare types of titanium oxo clusters are isolated from aqueous solutions of TiOSO₄ and TiCl₄ without using organic ligands. Our results indicate that titanium­(IV) is readily hydrolyzed into oxo oligomers even in highly acidic solutions. The present clusters provide precise structural information for future characterization of the solution species and structural evolution of titanium­(IV) in water and, meanwhile, are new molecular materials for photocatalysis

Small Titanium Oxo Clusters: Primary Structures of Titanium(IV) in Water

For sol–gel synthesis of titanium oxide, the titanium­(IV) precursors are dissolved in water to form clear solutions. However, the solution status of titanium­(IV) remains unclear. Herein three new and rare types of titanium oxo clusters are isolated from aqueous solutions of TiOSO₄ and TiCl₄ without using organic ligands. Our results indicate that titanium­(IV) is readily hydrolyzed into oxo oligomers even in highly acidic solutions. The present clusters provide precise structural information for future characterization of the solution species and structural evolution of titanium­(IV) in water and, meanwhile, are new molecular materials for photocatalysis

Atom Transfer Radical Addition to Alkynes and Enynes: A Versatile Gold/Photoredox Approach to Thio-Functionalized Vinylsulfones

An efficient intermolecular atom-transfer addition reaction of alkynes via the combination of visible-light photoredox catalysis and gold catalysis has been developed, affording diverse trifluoromethylthio- and difluoromethylthio-functionalized vinylsulfones with high stereoselectivity in good yields. Thiosulfonylation reaction of enyne can also be realized for constructing functionalized carbo- and heterocycles through a radical cascade cyclization process. These reactions proceed through a gold-assisted sulfonyl radical addition pathway