Reactions of a dimetallated N,N'-dimethyl substituted porphyrinogen Sm(II) complex with a series of t-butyl substituted heteroalkynes affords a diverse range of reactivity. The phosphaalkyne t-BuC[triple bond]P gives a dinuclear Sm(III) P-P reductively coupled complex of (t-BuC=PP=C-t-Bu)(2-) featuring a new mu-eta(2)(1,2-C,P) binding mode. In contrast, the nitrile aza analogue t-BuC[triple bond]N forms Sm(II) adducts that undergo reductive C-C bond cleavage at elevated temperatures to afford a trimeric Sm(III) cyanide (mu-C[triple bond]N(-)) complex. The isomeric isonitrile t-BuN[triple bond]C undergoes the related reductive C-N bond cleavage reactivity at milder temperatures, allowing the trapping of the tert-butyl fragment as a Sm(III) eta(2)-iminoacyl (t-BuC=N-t-Bu)(-) complex.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c002778b | DOI Listing |
Nat Commun
December 2024
National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive for performing a dearomatization/cleavage sequence. Here, we disclose a cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through a single-operation protocol. By converting a five-membered aza-arene into a five-unit spine of a 6/6 fused-bicyclic, this work unlocks a ring-opening reactivity of the pyrazole core that involves a formal C = N bond cleavage while retaining the highly reactive N-N bond in the resulting product.
View Article and Find Full Text PDFNat Commun
December 2024
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.
The activation of C-C bond of benzocyclobutenones under mild reaction conditions remains a challenge. We herein report a photoinduced catalyst-free regio-specific C1-C8 bond cleavage of benzocyclobutenones, enabling the generation of versatile ortho-quinoid ketene methides for aza-[4 + 2]-cycloaddition with imines, which offers a facile route to isoquinolinone derivatives, including seven family members of protoberberine alkaloids, gusanlung A, B, D, 8-oxotetrahydroplamatine, tetrahydrothalifendine, tetrahydropalmatine, and xylopinine. Furthermore, the catalytic enantioselective version of this strategy is also realized by merging synergistic photocatalysis and chiral Lewis acid catalysis.
View Article and Find Full Text PDFEnviron Technol
December 2024
School of Environmental Science and Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China.
Ascorbic acid (AA) was used as a reducing agent to improve the Fe(III)-activated peracetic acid (PAA) system for the removal of sulfamethoxazole (SMX) in this work. The efficiency, influencing factors and mechanism of SMX elimination in the AA/Fe(III)/PAA process were studied. The results exhibited that AA facilitated the reduction of Fe(III) to Fe(II) and subsequently improved the activation of PAA and HO.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing 400715, China; Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, Chongqing 400715, China. Electronic address:
The traditional gelatin extraction methods (acid-base) may hinder to their green applications due to mass energy consumption and pollution. Herein, we constructed a clean and sustainable gelatin extraction method, investigated the molecular mechanism of microwave treatment (0-360 min) and freeze-thaw on the gelatin extraction from the perspective of the crosslinking degree and hydrogen bonds. Microwave (0-60 min) can improve the hydrolysis degree (DH) and expose more enzyme cleavage sites of collagen by destroying the intramolecular and intermolecular covalent crosslinking.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
East China Normal University, School of Chemistry and Molecular Engineering, 3663 N. Zhongshan Rd., 200062, Shanghai, CHINA.
We present a novel electrochemical dicarboxylation of epoxides with CO2, characterized by the cleavage of two C-O single bonds. Not only are vinyl epoxides viable, but cyclic carbonates also serve as effective substrates, facilitating the synthesis of E-configured adipic and octanedioic acids with high chemo-, regio-, and stereoselectivity. The synthetic practicality is further highlighted by the diverse functionalizations of the resulting multifunctional diacids.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!