Unsymmetrical one-pot sequential cross-coupling reactions of sterically hindered tetrabromothiophene with arylboronic acid and an alkyne/alkene to afford selective bi-, tri-, and tetrasubstituted aryl/alkynyl-thiophenes with the aid of a palladium catalyst were described. The reaction proceeds via a site-selective Suzuki/Sonogashira coupling, followed by selective Sonogashira, Suzuki and Heck coupling reactions. This methodology has demonstrated an important framework for the synthesis of organic scaffolds.
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http://dx.doi.org/10.1039/c7ob02601c | DOI Listing |
Inorg Chem
January 2025
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, 7098 Liuxian Blvd, Nanshan District, Shenzhen 518055, P. R. China.
Metal-organic frameworks have received extensive development in the past three decades, which are generally constructed via the reaction between inorganic building units and commercially available or presynthesized organic linkers. However, the presynthesis of organic linkers is usually time-consuming and unsustainable due to multiple-step separation and purification. Therefore, methodology development of a new strategy is fundamentally important for the construction and further exploration of the applications of MOFs.
View Article and Find Full Text PDFOrg Lett
January 2025
Materials Tech Laboratory for Hydrogen & Energy Storage, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo 315201, P. R. China.
A new sequential deprotonation strategy of dimethyl sulfoxide (DMSO) and propargyl alcohol in the presence of a base was developed for the generation of the α-hydroxyl carbanion, which enables rapid and controllable access to a wide range of valuable highly functionalized furans in one pot from alkynes and aldehydes under transition-metal- and additive-free conditions. Preliminary mechanistic studies revealed the crucial role of the base and DMSO. More importantly, deuterium labeling experiments confirmed the formation of the α-hydroxyl carbanion.
View Article and Find Full Text PDFOrg Lett
January 2025
Laboratory of Catalysis and Organic Synthesis, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
Herein, we have reported the application of bench stable perfluoroalkanoic acids as fluoro-alkylating reagents in combination with DIB and primary amides for sequential one-pot transformation to R-embedded functionalized amides under metal-free conditions. The protocol is tolerant to a range of sensitive functional groups (>33 examples and up to 90% yield), and perfluoro acids. Preliminary mechanistic studies, control experiments, in situ F-NMR analyses, and the synthesis of intermediate species were performed to understand the reaction pathways.
View Article and Find Full Text PDFProteoglycan Res
October 2024
Department of Biochemistry and Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
Hyaluronan (HA; [-3-GlcNAc-1-beta-4-GlcA-1-beta] ), an essential matrix polysaccharide of vertebrates and the molecular camouflage coating in certain pathogens, is polymerized by "HA synthase" (HAS) enzymes. Three HAS classes have been identified with biotechnological utility, but only the Class II PmHAS from Type A has been useful for preparation of very defined HA polymers in vitro. Two general chemoenzymatic strategies with different size products are possible: (1) repetitive step-wise extension reactions by sequential addition of a single monosaccharide from a donor UDP-sugar onto an acceptor (or "primer") comprised of a short glycosaminoglycan chain (e.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Organo Catalysis and Synthesis, Department of Chemistry, Visvesvaraya National Institute of Technology (VNIT), Nagpur, Maharashtra 440010, India.
A practically intriguing catalytic domino methodology has been developed for the synthesis of highly functionalized pyran and ethene-1,1,2-tricarbonitrile derivatives in a single-pot operation. The -dicyano olefins and the corresponding epoxide were taken as the reactive partners in the presence of a hydrogen bond donor (HBD)-catalyzed condition. The reaction was found to be highly efficient in terms of the formation of sequential C-C and O-C bonds along with an exceptional C-C coupling step through a metal-free organocatalytic pathway.
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