B₁₂-Catalyzed Generation of Allylic Chromium Reagents from 1,3-Dienes, CrCl₂, and Water

B12-Catalyzed Generation of Allylic Chromium Reagents from 1,3-Dienes, CrCl2, and Wate

Rhenium-Catalyzed Cyclization via 1,2-Iodine and 1,5-Hydrogen Migration for the Synthesis of 2‑Iodo‑1<i>H</i>‑indenes

A rhenium complex catalyzed the formation of 2-iodo-1H-indene derivatives through iodine and hydrogen migration of 3-iodopropargyl ethers. The reaction proceeded via generation of 1-iodoalkenylrhenium carbene species by sequential 1,2-iodine and 1,5-hydrogen shifts with readily available precursors under neutral conditions. The reaction mechanism and the reactivity of the generated alkenylcarbene species were also investigated

Indium-Catalyzed Reduction of Allyl Bromide with Gallium or Aluminum. Formation of Allylgallium and Allylaluminum Sesquibromides

Fast transmetalation of an allyl group from indium to gallium enables the assembly of a catalytic cycle of indium, which accelerates the formation of allylgallium sesquibromide. A solution of allylaluminum sesquibromide in THF is also prepared from allyl bromide and aluminum metal under indium catalysis

B₁₂-Catalyzed Generation of Allylic Chromium Reagents from 1,3-Dienes, CrCl₂, and Water

B12-Catalyzed Generation of Allylic Chromium Reagents from 1,3-Dienes, CrCl2, and Wate

Correction to Palladium-Catalyzed Synthesis of Dibenzophosphole Oxides via Intramolecular Dehydrogenative Cyclization

Correction to Palladium-Catalyzed Synthesis of Dibenzophosphole Oxides via Intramolecular Dehydrogenative Cyclizatio

Amine-Promoted <i>anti</i>-Markovnikov Addition of 1,3-Dicarbonyl Compounds with Terminal Alkynes under Rhenium Catalysis

Amines have been identified to greatly accelerate the intermolecular <i>anti</i>-Markovnikov addition of carbon nucleophiles to unactivated terminal alkynes. Using a combination of [ReBr­(CO)₃(thf)]₂ and ^<i>i</i>Pr₂NEt, construction of cyclic all-carbon quaternary centers was achieved with various 1,3-ketoesters, diketones, and diesters with lower catalyst loading under milder conditions. The type of addition could be easily controlled by choice of additive, highlighting the unique features of rhenium catalysi

Rhenium-Catalyzed Formation of Indene Frameworks via C−H Bond Activation: [3+2] Annulation of Aromatic Aldimines and Acetylenes

A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the reaction of an aromatic aldimine with an acetylene to give an indene derivative in a quantitative yield. The reaction proceeds via C−H bond activation, insertion of the acetylene, intramolecular nucleophilic cyclization, and reductive elimination. In contrast to ruthenium and rhodium catalysts, which are usually employed in this type of reaction, the rhenium catalyst promotes the intramolecular nucleophilic cyclization of the alkenylmetal species generated by insertion of the acetylene

Efficient Catalytic Insertion of Acetylenes into a Carbon−Carbon Single Bond of Nonstrained Cyclic Compounds under Mild Conditions

A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the reaction of a 1,3-dicarbonyl cyclic compound with an acetylene to give a medium-sized cyclic compound in excellent yield. By using isocyanide as an additive, the catalytic activity of the rhenium complex changes dramatically, and the insertion of acetylenes into a carbon−carbon single bond occurs under mild conditions. A plausible mechanism is that the reaction proceeds via the formation of a rhenacyclopentene intermediate, ring opening by a retro-aldol reaction, isomerization, and reductive elimination

Palladium-Catalyzed Synthesis of Dibenzophosphole Oxides via Intramolecular Dehydrogenative Cyclization

Dibenzophosphole oxides were obtained from secondary hydrophosphine oxides with a biphenyl group by dehydrogenation via phosphine–hydrogen and carbon–hydrogen bond cleavage in the presence of a catalytic amount of palladium(II) acetate, Pd(OAc)2. By using this reaction, a ladder-type dibenzophosphole oxide could also be synthesized by double intramolecular dehydrogenative cyclization