Chinese Journal of Chemistry最新文献

Organosilicon compounds are widely valuable, making the efficient synthesis of alkenyl silanes an important research goal. A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for the Markovnikov-selective hydrosilylation of terminal aliphatic alkynes, followed by isomerization of the disubstituted alkenyl silane intermediate, providing efficient access to trisubstituted alkenyl silanes. This system is also highly effective for the Markovnikov hydrosilylation of aryl alkynes. The protocol demonstrates broad functional group tolerance and can be performed on a gram scale. The catalyst achieves a turnover number (TON) of up to 1760 in hydrosilylation reaction. Mechanistic studies suggest that the anionic ligand, upon coordination, forms a dual functional catalyst with cobalt, which is key to enabling this transformation. It is proposed that a cobalt-hydride species selectively catalyzes both the hydrosilylation of terminal alkynes and the subsequent isomerization of the disubstituted alkenyl silane. This work provides an efficient and selective synthetic method using an earth-abundant metal catalyst for alkene synthesis via hydrosilylation and isomerization.

Transition-metal catalyzed reductive carbosilylation of alkenes with carbon and silyl electrophiles has gained considerable attention for synthetic chemists recently, because it avoids air- and moisture-sensitive pre-prepared organometallic reagents used. However, current carbon electrophiles are limited to alkyl or aryl bromides. Therefore, developing new synthetic approaches by choosing more easily available carbon electrophiles is still in high demand. Herein, we describe a nickel-catalyzed protocol that enables alkylsilylation of acrylonitrile with chlorosilanes and alkyl carboxylic acids via NHPI esters for the construction of various alkylsilanes, in which abundant and easy-accessible carboxylic acids were employed as the new alkyl electrophile sources, overcoming current limitations. This represents the first example of utilizing carboxylic acid as the alkyl reagent in reductive silylative alkylation of alkenes, thus providing a valuable complement to existing methodologies for the synthesis of a variety of organosilanes with diverse structures. Our approach also showcases broad substrate scope (including primary, secondary and tertiary carboxylic acids), good functional group compatibility (tolerating halides, heterocycles, Boc-protected amine, ester, ketone, terminal and internal alkenes, and terminal alkyne) and offers the capability for post-modification of complex agrochemical and pharmaceuticals. In addition, gram-scale reaction further demonstrates the applicable potential of the developed method. Overall, this protocol not only expands the boundaries of reductive difunctionalization reactions of alkenes but also enriches the synthetic toolbox for alkylsilane compounds preparation.

Aminyl radicals of the type •NR₂, featuring a nitrogen-centered unpaired electron, are highly reactive intermediates that are notoriously difficult to isolate in the condensed phase. Herein, we report the synthesis of thio-, seleno- and telluro-aminyl radicals 2–4, obtained in one step from reactions of an isolable triplet nitrene with diphenyldichalcogenides. Radicals 3 and 4 represent the first stable examples of seleno- and telluro-substituted aminyl radicals. Compounds 2–4 were characterized by single-crystal X-ray diffraction, electron paramagnetic resonance and UV/Vis absorption spectroscopy. This work not only expands the family of isolable nitrogen-centered radicals, but also opens new avenues for main-group radical chemistry involving heavier p-block elements.

Water microdroplets provide a unique environment that facilitates chemical reactions at the air-water interface. Here, we provide mass spectrometric evidence that several types of fluorinated ethanol increase their acidity and undergo efficient deprotonation at the air–water interface of microdroplets, generating anions that capture CO₂ to form stable fluoroethoxyformate products. While increased fluorine substitution enhances the acidity by stabilizing conjugate bases through electron-withdrawing effect, it simultaneously reduces the nucleophilicity of the bases by delocalizing their negative charges from oxygen atoms. This correlation between acidity of fluorinated ethanols and nucleophilicity of their conjugate bases results in monofluorinated ethanol exhibiting the highest reactivity toward CO₂. Our results elucidate how fluorine substitution modulates anion reactivity and provide a strategy for CO₂ capture in microdroplets where the acidity of various substances could be greatly increased.

Organic solar cells (OSCs) leveraging non-fullerene acceptors (NFAs) have achieved power conversion efficiencies (PCEs) exceeding 20%, yet their performance critically depends on the nanoscale morphology of the bulk heterojunction (BHJ). Ternary blending is a promising strategy for enhancing photovoltaic parameters and morphology control, but simultaneously optimizing phase separation size, vertical phase distribution, and crystallinity remains challenging. Herein, a new L8-BO-derived non-fullerene acceptor, namely BTP- HFCP, featuring a heptafluorocyclopentenyloxy–octyl side chain was developed. When it was integrated as a third component into the D18:L8-BO binary system, BTP-HFCP acts as an effective morphological modulator. Adv. characterizations reveal that the ternary device exhibits a significantly enhanced vertical phase distribution, optimal phase separation and balanced crystallinity, thereby improving chargecollection and reducing recombination. Consequently, the ternary OSC achieves a champion PCE of 19.32%, surpassing the binary OSC. This work demonstrates that heptafluoropentane side-chain engineering of the third component provides a rational molecular design strategy for precise morphology control in high efficiency ternary OSCs.