A highly effective silver-catalyzed formal inverse electron-demand Diels-Alder reaction of 1,2-diazines and siloxy alkynes has been developed. The reactions provide ready access to a wide range of siloxy naphthalenes and anthracenes, which are formed in good to high yields, under mild reaction conditions, using low catalyst loadings.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3415592 | PMC |
http://dx.doi.org/10.1021/ja302537j | DOI Listing |
J Org Chem
July 2023
State Key Laboratory, College of Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Weijin Road 94, Tianjin 300071, China.
Herein, we report a mild, one-pot method for silver-catalyzed tandem cycloisomerization/[5 + 2] cycloaddition reactions between readily accessible cyclopropyl-tethered allenyl ketones and benzopyranone-derived oxidopyrylium ylides. The reactions proceed a cyclobutene-fused furan intermediate generated by a cycloisomerization/1,2-carbene transfer/ring-expansion cascade. This method, which features an unprecedented formal [5 + 2] cycloaddition, delivers good to excellent yields of structurally complex bibridged benzocycloheptanones bearing a strained cyclobutane ring and an -bridged ring.
View Article and Find Full Text PDFOrg Lett
November 2022
Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024, China.
We describe the silver-catalyzed formal insertion of a vinylcarbene into unstrained C(CO)-C bonds of 1,3-diketones using vinyl--triftosylhydrazones as vinylcarbene precursors. This method allows the rapid synthesis of otherwise inaccessible 2-vinyl-substituted 1,4-diketones from relatively simple substrates. This mild catalytic protocol exhibits a good functional group tolerance and substrate scope and allows for good chemoselectivity control.
View Article and Find Full Text PDFOrg Lett
January 2022
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Herein we have developed the silver-catalyzed electronic- and steric-controlled intramolecular formal [2 + 2]-cycloaddition of alkyne-tethered cyclohexadienones. Substrates with electron-rich alkynes and a less hindered quaternary carbon center afford tricyclic fused cyclobutenes through 1,7-enyne cyclization. In contrast, the formation of dihydrofurans was observed from electron-deficient alkynes via proton abstraction/C-O bond cleavage.
View Article and Find Full Text PDFOrg Lett
January 2022
Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China.
Here we report a silver-catalyzed alkynyl carbene insertion into β-ketocarbonyls using alkynyl -nosylhydrazones as alkynyl carbene precursors, which provides access to trisubstituted allenyl ketones. This reaction represents the first example of an alkynyl carbene insertion into a C-C σ bond, affording products homologated with an sp carbon center. The products are useful substrates for further transformations.
View Article and Find Full Text PDFOrg Lett
October 2020
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, P.R. China.
A silver-catalyzed formal [3 + 2] cycloaddition reaction, with cyclopropanols as a C3 subunit and imines as a two-atom subunit, is developed. The reaction takes place under mild conditions and produces a broad array of polysubstituted pyrroles in medium to high yields. It represents the first example of oxidative radical addition to imines, thus offering a new choice for the direct C-H functionalization of imines.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!