Synthesis and Reaction of [(Tp^{<i>i</i>Pr₂})LnH₂]₃ (Ln = Y, Lu) with CO: Trinuclear Cluster-Bound Propenolate en Route to Selective Formation of Propene

Synthesis and Reaction of [(TpiPr2)LnH2]3 (Ln = Y, Lu) with CO: Trinuclear Cluster-Bound Propenolate en Route to Selective Formation of Propen

Synthesis and Reaction of [(Tp^{<i>i</i>Pr₂})LnH₂]₃ (Ln = Y, Lu) with CO: Trinuclear Cluster-Bound Propenolate en Route to Selective Formation of Propene

Synthesis and Reaction of [(TpiPr2)LnH2]3 (Ln = Y, Lu) with CO: Trinuclear Cluster-Bound Propenolate en Route to Selective Formation of Propen

Catalytic Boracarboxylation of Alkynes with Diborane and Carbon Dioxide by an N‑Heterocyclic Carbene Copper Catalyst

By the use of an N-heterocyclic carbene copper­(I) complex as a catalyst, the boracarboxylation of various alkynes (e.g., diaryl alkynes, aryl/alkyl alkynes, and phenylacetylene) with a diborane compound and carbon dioxide has been achieved for the first time, affording the α,β-unsaturated β-boralactone derivatives regio- and stereoselectively via a borylcupration/carboxylation cascade. Some important reaction intermediates were isolated and structurally characterized to clarify the reaction mechanism

Catalytic Boracarboxylation of Alkynes with Diborane and Carbon Dioxide by an N‑Heterocyclic Carbene Copper Catalyst

By the use of an N-heterocyclic carbene copper­(I) complex as a catalyst, the boracarboxylation of various alkynes (e.g., diaryl alkynes, aryl/alkyl alkynes, and phenylacetylene) with a diborane compound and carbon dioxide has been achieved for the first time, affording the α,β-unsaturated β-boralactone derivatives regio- and stereoselectively via a borylcupration/carboxylation cascade. Some important reaction intermediates were isolated and structurally characterized to clarify the reaction mechanism

Heteroleptic Tm(II) Complexes: One More Success for Trofimenko's Scorpionates

Reaction of TmI2(THF)x with the bulky scorpionate, KTptBu,Me, gave (TptBu,Me)TmI(THF) (1). Complex 1 proved to be a useful starting material for a select number of heteroleptic Tm(II) compounds, (TptBu,Me)TmER, including the first Tm(II)-hydrocarbyl derivative, (TptBu,Me)Tm{CH(SiMe3)2} (2)

Heteroleptic Tm(II) Complexes: One More Success for Trofimenko's Scorpionates

Reaction of TmI2(THF)x with the bulky scorpionate, KTptBu,Me, gave (TptBu,Me)TmI(THF) (1). Complex 1 proved to be a useful starting material for a select number of heteroleptic Tm(II) compounds, (TptBu,Me)TmER, including the first Tm(II)-hydrocarbyl derivative, (TptBu,Me)Tm{CH(SiMe3)2} (2)

Tandem Synthesis of Linear Hydridopolycarbosilanes and Postfunctionalization by a Calcium Catalyst

Recent years have witnessed great progress in the application of calcium-based catalysts in a variety of organic transformations, including hydrofuctionalization, dehydrogenative coupling, and C–H activation. However, these efficient protocols in polymer synthesis remain much less explored. Here, we report the selective bis-hydrosilylation of dienes with bis-hydrosilanes in the presence of scorpionate-supported calcium benzyl complex [(TpAd,iPr)­Ca­(p-CH2–C6H4-Me)­(THP)] (TpAd,iPr = hydrotris­(3-adamantyl-5-isopropyl-pyrazolyl)­borate, THP = tetrahydropyran) (1) to obtain linear polycarbosilanes containing a reactive SiH2 unit in the main chain. Furthermore, complex 1 can also catalyze the dehydrogenative silylation of terminal alkyne, silylamination of aniline, and C–H activation of 1-methyl-1H-indole, with the Si–H bonds in polycarbosilanes to allow the introduction of 35–65% new side chains in these polymers. The resulting new polymers contain unusual units including SiH–(CCPh), SiH–(NHAr), and SiH–(indole), whose presence is confirmed by NMR and IR spectra

Time course of PFOS defluorination in activated K₂S₂O₈ oxidation systems.

<p>Time course of PFOS defluorination in activated K₂S₂O₈ oxidation systems.</p

Regioselective C–H Alkylation of Aromatic Ethers with Alkenes by a Half-Sandwich Calcium Catalyst

The catalytic ortho-regioselective C–H alkylation of a variety of alkoxy-substituted benzene derivatives with alkenes can be achieved by the use of a half-sandwich calcium alkyl complex [(CpAr5)­Ca­{CH­(SiMe3)2}­(THF)] (2) (CpAr5 = C5Ar5, Ar = 3,5-iPr-C6H3) as the precatalyst. The potential catalytic reaction intermediates, half-sandwich calcium anisyl complexes [(CpAr5)­Ca­(o-MeO-m-Ph-C6H3) (THF)2] (8) and [(CpAr5)­Ca­(o-MeO-2-Np) (THF)2] (9) (Np = naphthyl), were isolated and X-ray structurally characterized. DFT calculations were carried out to elucidate the different reaction profiles of sp2 and sp3 C–H activations

Defluorination of Aqueous Perfluorooctanesulfonate by Activated Persulfate Oxidation

<div><p>Activated persulfate oxidation technologies based on sulfate radicals were first evaluated for defluorination of aqueous perfluorooctanesulfonate (PFOS). The influences of catalytic method, time, pH and K₂S₂O₈ amounts on PFOS defluorination were investigated. The intermediate products during PFOS defluorination were detected by using LC/MS/MS. The results showed that the S₂O₈²⁻ had weak effect on the defluorination of PFOS, while the PFOS was oxidatively defluorinated by sulfate radicals in water. The defluorination efficiency of PFOS under various treatment was followed the order: HT (hydrothermal)/K₂S₂O₈ > UV (ultraviolet)/K₂S₂O₈ > Fe²⁺/K₂S₂O₈ > US (ultrasound)/K₂S₂O₈. Low pH was favorable for the PFOS defluorination with sulfate radicals. Increase in the amount of S₂O₈²⁻ had positive effect on PFOS defluorination. However, further increase in amounts of S₂O₈²⁻ caused insignificant improvement in PFOS defluorination due to elimination of sulfate radicals under high concentration of S₂O₈²⁻. CF₃(CF₂)_nCOOH (n = 0–6) were detected as intermediates during PFOS defluorination. Sulfate radicals oxidation and hydrolysis were the main mechanisms involved in defluorination process of PFOS.</p></div