[reaction: see text] 2-Deoxy-C-aryl glycosides are potential synthetic targets as they form a very vital moiety of several biologically active natural products. This paper describes a synthetic route using an umpolung strategy, which has not been explored till date. Our synthetic endeavor led to a versatile intermediate aryl ketone 10, which has paved the way for two important classes of C-glycosides, viz., C-alkyl furanosides 12 and methyl 2-deoxy-C-aryl pyranosides 14.
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http://dx.doi.org/10.1021/ol025794w | DOI Listing |
J Org Chem
December 2024
Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577, Japan.
Versatile P-N and P-O bond-forming reactions by an umpolung approach using air- and moisture-stable hydroxymethylphosphine sulfides were developed. Phosphine sulfides containing multiple hydroxymethyl groups could undergo sequential transformations combining P-N and P-O as well as P-C bond formations, providing a novel protocol for the synthesis of a variety of organophosphorus(V) compounds with P-N and P-O bonds.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
Asymmetric catalytic versions of electricity-driven processes hold immense potential for the sustainable preparation of chiral compounds. However, the involvement of anodic oxidative cross-dehydrogenative coupling events between two distinct nucleophiles makes it challenging for a chiral catalyst to regulate the stereochemistry of the products. Our current electrocatalytic strategy for enantioconvergent cross-dehydrogenative α- and γ-nitroalkylation via radical-based pathways produces an array of enantioenriched nitroesters without supplementary stoichiometric oxidants.
View Article and Find Full Text PDFChem Commun (Camb)
November 2024
Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab-140001, India.
Visible light-induced radical umpolung chemistry is utilized to synthesize trifluoromethylated unnatural α-amino acid and amine derivatives. This approach utilizes photoredox catalysis to perform a single-electron-transfer reduction of imines generating a N-centred radical that eventually migrates to the C-centre followed by a radical-radical cross-coupling to deliver reductive trifluoromethylation products.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560012, India.
The umpolung of aldimines using N-heterocyclic carbenes (NHCs) is less explored compared to the established polarity reversal of aldehydes. Described herein is an NHC-catalyzed imine umpolung /6π-electrocyclization cascade, which leads to the atom- and pot-economic synthesis of biologically important dihydrochromeno indoles. For the first time, the nucleophilic aza-Breslow intermediates have been intercepted with unactivated alkynes.
View Article and Find Full Text PDFOrg Lett
October 2024
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Phosphorylated tyrosine is a fundamental building block of bioactive peptides and proteins. However, the chemoselective phosphorylation of tyrosine over other nucleophilic amino acid residues in unprotected peptides remains a significant challenge. Here we report an umpolung strategy that converts the C-terminal tyrosine into an electrophilic spirolactone cyclohexadienone motif through hypervalent iodine oxidation, followed by a 1,2-phospha-Brook rearrangement using phosphite diesters as nucleophilic phosphoryl donors.
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