Copper-Catalyzed Sulfimidations of Benzylic C(sp3)-H Bonds

In this study, we elucidate a novel strategy for benzylic C(sp3)-H activation, enabling the construction of C-S bonds through a copper-catalyzed sulfimidation process. Leveraging readily available methylarenes as substrates, our methodology offers an economically efficient and highly viable approach. The scalability of the reaction, its applicability to a broad range of substrates, and significant application value underscore its potential and transformative impact in the realm of synthetic organic chemistry

S-Trideuteromethylation of Sulfenamides: Redox-Neutral Synthesis of Trideuteromethyl Sulfilimines

This study presents an innovative approach to the synthesis of trideuteriosulfilimines, a class of sulfur(IV)-derived compounds with significant potential in organic synthesis and medicinal chemistry. Our research focused on the modification of sulfenamides and the introduction of a deuterated methyl group, employing an electrophilic trideuteromethylating reagent in an anionic reaction. The method demonstrated broad applicability across various sulfenamides derived from different amides, alkyl amides, and aryl amides, as well as thiol-derived sulfenamides. The reactions generally resulted in excellent yields and high deuteration rates. The study also explored the reaction mechanism, confirming that the process does not proceed via a free radical pathway. This research contributes to the development of efficient and reliable methods for the synthesis of sulfilimines, which are valuable building blocks in organic synthesis and medicinal chemistry

Transition-Metal-Free and Redox-Neutral Strategy for Sulfilimines Synthesis via S-Arylation of Sulfenamides

In this investigation, an unprecedented transition-metal-free and redox-neutral synthesis of sulfilimines was realized through the S-arylation of readily obtainable sulfenamides employing diaryliodonium salts. The pivotal step encompassed the tautomerization between bivalent nitrogen-centered anions, engendered post-deprotonation of sulfenamides under alkaline conditions, and sulfinimidoyl anions. The experimental outcomes demonstrate that sulfinimidoyl anionic species function as efficacious nucleophilic reagents, affording sulfilimines with notable to exceptional yields and superlative chemoselectivity, all executed within a transition-metal-free protocol and under exceptionally mild conditions

Redox-Neutral Synthesis of Sulfilimines through the S-Alkylation of Sulfenamides

Sulfilimines are a class of bioisosteres with immense potential in medicinal chemistry, characterized by the presence of a tetravalent sulfur atom bearing one nitrogen and two distinct carbon substitutes. The conventional methods for synthesizing sulfilimines, relying on metal-catalyzed oxidative thioesters, suffer from a poor atomic economy and wastage of resources. To this end, we present a metal-free and redox-neutral approach for the first selective S-alkylation of sulfenamides under basic conditions to obtain sulfilimines. Our sustainable and efficient strategy involves sulfur-selective alkylation of easily accessible sulfenamides and commercially available halogenated hydrocarbons, leading to the successful synthesis of 60 sulfimides with high yields (36–99%) in a short reaction time. This novel approach not only offers a promising alternative to traditional methods but also expands the synthetic toolbox for the preparation of sulfilimines in medicinal chemistry

Cu(II)-Catalyzed Aerobic Synthesis of Sulfinamidines from Sulfenamides

Inhere, the first instance of copper-catalyzed oxidative amination of sulfenamides for the synthesis of sulfinamidines was documented. Employing air as the terminal oxidant, a variety of secondary and primary amines can be effectively transformed into their target products. This reaction boasts excellent chemoselectivity, mild conditions, straightforward operation, and broad substrate compatibility, which has significant implications for the fields of pharmaceuticals and organic synthesis

A numerical study of non-Darcy flow in EGS heat reservoirs during heat extraction

Underground non-Darcy fluid flow has been observed and investigated for decades in the petroleum industry. It is deduced by analogy that the fluid flow in enhanced geothermal system (EGS) heat reservoirs may also be in the non-Darcy regime under some conditions. In this paper, a transient 3D model was presented, taking into consideration the non-Darcy fluid flow in EGS heat reservoirs, to simulate the EGS long-term heat extraction process. Then, the non-Darcy flow behavior in water- and supercritical CO2 (SCCO2)-based EGSs was simulated and discussed. It is found that non-Darcy effects decrease the mass flow rate of the fluid injected and reduce the heat extraction rate of EGS as a flow resistance in addition to the Darcy resistance which is imposed to the seepage flow in EGS heat reservoirs. Compared with the water-EGS, the SCCO2-EGS are more prone to experiencing much stronger non-Darcy flow due to the much larger mobility of the SCCO2. The non-Darcy flow in SCCO2- EGSs may thus greatly reduce their heat extraction performance. Further, a criterion was analyzed and proposed to judge the onset of the non-Darcy flow in EGS heat reservoirs. The fluid flow rate and the initial thermal state of the reservoir were taken and the characteristic Forchheimer number of an EGS was calculated. If the calculated Forchheimer number is larger than 0.2, the fluid flow in EGS heat reservoirs experiences non-negligible non-Darcy flow characteristic

Hydration and Properties of Cement in the Belite-Ye′elimite-Ternesite System

Energy consumption and carbon emissions are lower in the production of belite-ye′elimite-ternesite (C2S-C4A3$-C5S2$, BYT) clinker than Portland cement (PC) clinker. BYT cement can combine the early strength of CSA cements and the durability of belite cements. X-ray diffraction, mercury intrusion porosimetry, isothermal conduction calorimetry and scanning electron microscope were conducted to investigate the hydration process of BYT cement. The hydration products of BYT cement include mainly ettringite, strätlingite and some amorphous AH3 (aluminum hydroxide). Ternesite did prove an early reactivity in BYT cement. The reaction of ternesite with AH3 occurs on the surface of ternesite. Ternesite delays the second heat flow peak of ye′elimite. The strength of BYT cement containing 10% ternesite in the prepared clinker exceeds that of other cement at all ages