The reaction of LH [L = {(ArNH)(ArN)-C=N-C=(NAr)(NHAr)}; Ar =2,6-Et-CH] with a commercially available alane amine adduct (HAl·NMeEt) in toluene resulted in the formation of a conjugated bis-guanidinate (CBG)-supported aluminum dihydride complex, i.e., LAlH (), in good yield. The new complex has been thoroughly characterized by multinuclear magnetic resonance, IR, mass, and elemental analyses, including single-crystal structural studies. Further, we have demonstrated the aluminum-catalyzed hydroboration of a variety of nitriles and alkynes. Moreover, aluminum-catalyzed hydroboration is expanded to more challenging substrates such as alkene, pyridine, imine, carbodiimide, and isocyanides. More importantly, we have shown that the aluminum dihydride catalyzed both intra- and intermolecular chemoselective hydroboration of nitriles and alkynes over other reducible functionalities for the first time.
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http://dx.doi.org/10.1021/acs.joc.0c00234 | DOI Listing |
Chem Commun (Camb)
January 2025
Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.
Herein, we have developed a Pd(II)-catalyzed cyclization of prochiral alkyne-tethered malononitriles to access five-membered carbocycles having a nitrile-containing all-carbon quaternary center. The reaction pathway involves a -acetoxypalladation, nitrile group insertions into the carbon-palladium bond and sequential deacetylation followed by -acetylation. Initial studies on asymmetric cyclization were also performed with chiral Pyox ligands.
View Article and Find Full Text PDFOrg Lett
December 2024
College of Chemistry and Chemical Engineering, Qingdao University, 308 Ningxia RoadQingdao 266071, China.
Here, we report an electrochemical approach to generate an aldoxime-substituted nitrile oxide via the activation of nitromethane. The Cu-catalyzed Huisgen reaction of this 1,3-dipole with alkynes enables successful preparation of 48 new isoxazole aldoximes, which are typically challenging to synthesize by other methods, in 52 to 97% yields with excellent regioselectivity and chemoselectivity in a single step. Moreover, 20 3,3'-bisisoxazoles are prepared from the isoxazole aldoxime products in good yields via a two-step sequence.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Natural Product and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
J Colloid Interface Sci
March 2025
School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK. Electronic address:
Controllable surface modification of nanoparticulate drug delivery vectors is key to enhancing specific desirable properties such as colloidal stability, targeting, and stimuli-responsive cargo release. Metal-organic frameworks (MOFs) have been proposed as potential delivery devices, with surface modification achieved by various bioconjugate "click" reactions, including copper-catalysed and strain-promoted azide-alkyne cycloaddition. Herein, we show that photo-induced nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) can be used to surface-modify tetrazole-appended Zr MOFs with maleimides, and vice versa, with the extent of this traceless surface functionalisation controlled by the length of photoirradiation.
View Article and Find Full Text PDFChem Rev
December 2024
Laboratory of Organic Chemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, Netherlands.
Click chemistry has become one of the most powerful construction tools in the field of organic chemistry, materials science, and polymer science, as it offers hassle-free platforms for the high-yielding synthesis of novel materials and easy functionalization strategies. The absence of harsh reaction conditions or complicated workup procedures allowed the rapid development of novel biofunctional polymeric materials, such as biopolymers, tailor-made polymer surfaces, stimulus-responsive polymers, etc. In this review, we discuss various types of click reactions─including azide-alkyne cycloadditions, nucleophilic and radical thiol click reactions, a range of cycloadditions (Diels-Alder, tetrazole, nitrile oxide, etc.
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