Inducing an intramolecular reaction is a powerful means of accelerating reactions. Though this mechanism of catalysis is common in enzymes, it is underutilized in synthetic catalysts. This article outlines our group's recent efforts to use reversible covalent bonding to induce an intramolecular reaction, allowing for rate acceleration as well as control of the selectivity in the desymmetrization of 1,2-diols.
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http://dx.doi.org/10.1055/s-0031-1290321 | DOI Listing |
Org Chem Front
December 2024
Department of Chemistry, University of Basel St Johanns-Ring 19 Basel 4056 Switzerland https://www.chemie1.unibas.ch/Bmayor/.
This work explores the use of a cross-shaped organic framework that is used as a template for the investigation of multi-functionalized chromophores. We report the design and synthesis of a universal cross-shaped building block bearing two bromines and two iodines on its peripheral positions. The template can be synthesized on a gram scale in a five-step reaction comprising an oxidative homo-coupling macro-cyclization.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Herein, we present the enantioselective synthesis of 2,3-dihydro-4-quinolones bearing chiral tetrasubstituted carbons from isatins and 2'-aminoacetophenones. The transformation is mediated by a chiral phosphoric acid catalyst and proceeds via an generated ketimine and subsequent enantioselective intramolecular cyclization. The methodology features a broad scope and functional group tolerance with yields and enantioselectivities of up to 99% and 98% ee.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmaceutical Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China.
Given the widespread presence of fluoroalkyl functionalities in bioactive molecules, the development of fluoroalkylation reactions with bench-stable and easy-to-use fluoroalkylating reagents is highly desirable. In addition, realization of mono-, di-, tri-, or polyfluoroalkyation usually requires distinct types of fluoroalkylating reagents under different or even harsh reaction conditions, and a universal method to accomplish different hydrofluoroalkylation of alkenes is lacking. Herein, the use of quaternary fluoroalkyl alcohols is reported as the universal fluoroalkylating reagents to readily facilitate mono-, di-, tri-, or polyfluoroalkylation of a wide range of alkene substrates in high yields.
View Article and Find Full Text PDFChem Asian J
December 2024
Indian Institute of Science Education and Research Bhopal Department of Chemistry, Chemistry, Room No. 226, Academic Block - 2, Indore By-pass Road, Bhauri, 462066, Bhopal, INDIA.
A practical and efficient reaction for C2-selenylation of 1,4-naphthoquinones has been explored. This coupling reaction of two redox structural motifs, such as 2-bromo-1,4-naphthoquinone with diaryldiselenide / ebselen has been achieved by using sodium borohydride reducing agent at room temperature. Using this approach, several 2-selenylated-1,4-naphthoquinones were obtained in moderate to good yields and thoroughly characterized by multinuclear (1H, 13C, and 77Se) NMR, cyclic voltammetry, and mass spectrometry.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia.
Transpeptidases are specialized enzymes that have evolved for site-selective modification of peptides and proteins at their backbone termini. Approaches for adapting transpeptidases to catalyze side chain modifications are substantially more restricted, and typically rely on large recognition tags or require specific reaction conditions that are not easily compatible with broader applications. Here we show that the engineered asparaginyl ligase AEP1 catalyzes direct isopeptide ligation by accepting an internal 2,3-diaminopropionic acid (Dap) residue adjacent to Leu, a motif that mimics the canonical N-terminal Gly-Leu substrate.
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