The intramolecular 1,2-aminoboration of alkynes by aminoboranes is rare and invariably requires a catalyst to proceed, while the intermolecular aminoboration of alkynes is yet entirely unknown. Through an exploration of the significance of electronics in alkynes for activating the B-N σ-bond of aminoboranes, we demonstrate in this work the first intermolecular 1,2-aminoboration of alkynes. These reactions employ a series of (amino)dihaloboranes and aminoboronic esters, mild reaction conditions, and no catalysts, yielding syn-addition alkene products with the incorporation of two crucial functionalities: amino and boryl. While highly electron-rich examples can afford the aminoborated products (Z)-2-borylethenamines, other alkynes, including unactivated and less electron-rich examples, do not lead to the corresponding aminoborated products due to the fundamental impediment that the reactions are significantly endergonic.
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http://dx.doi.org/10.1002/anie.202413370 | DOI Listing |
Chem Sci
January 2025
Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China
Protein lysine crotonylation has been found to be closely related to the occurrence and development of various diseases. Currently, site identification of crotonylation is mainly dependent on antibody enrichment; however, due to the cost, heterogeneity, and specificity of antibodies, it is desired to develop an alternative chemical tool to detect crotonylation. Herein, we report an alkynyl-functionalized bioorthogonal chemical probe, Cr-alkyne, for the detection and identification of protein lysine crotonylation in mammalian cells.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India.
A site-selective coupling involving quinoxalin-2-ones with alkenes and alkynes has been developed through synergistic visible-light photoredox cobalt catalysis. This method enables C3-selective alkylation and alkenylation of both -substituted and -unsubstituted quinoxalin-2-ones, achieving high yields under mild conditions. Of note, the protocol facilitates the incorporation of two alkene units, leading to a formal three-component coupling, whereas a two-component coupling is preferred for alkynes.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Axially chiral -VQMs have been extensively investigated as key intermediates to approach miscellaneous chiral structures. By sharp contrast, their structural isomers -VQMs have not been previously documented. The major reason, which results in the significant delay, may ascribe to the inherent challenges in the enantioselective activation of alkynes in a remote manner.
View Article and Find Full Text PDFChemistry
January 2025
Université de Montréal, FRQNT Centre in Green Chemistry and Catalysis, Centre for Continuous Flow Synthesis, Department of Chemistry, 1375 av. Thérèse Lavoie-Roux, Montréal, QC, H2V 0B3, Canada.
The pentafluorosulfanyl (SF-) group has been the subject of a surge of interest in the past decade, but there is still little practicality associated with its synthesis and installation. Herein is reported the first continuous flow synthesis of pentafluorosulfanyl chloride (SFCl), the most common reagent for the synthesis of SF-substituted compounds. The synthesis is based on inexpensive and easy-to-handle reagents: sulfur powder (S), trichloroisocyanuric acid (TCCA) and potassium fluoride (KF).
View Article and Find Full Text PDFOrg Lett
January 2025
Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Rd, Wuhan 430072, China.
An enantioselective oxypalladation/malononitrile addition cascade reaction of alkyne-tethered malononitriles was reported to synthesize enaminones bearing an all-carbon quaternary center. Using Pd(TFA)/Pyox as a precatalyst, an array of enaminone products were obtained in moderate overall yields, with excellent er (93.5:6.
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