Search

Herein, we report a concise and efficient formal synthesis of (+)-hannokinol. Key to this new strategy is the use of a chiral Horner–Wittig reagent, readily available from 2-deoxy-D-ribose, to introduce the chiral 1,3-diol motif. [ABSTRACT FROM AUTHOR]

One of the most useful transformations in the synthetic chemist arsenal is the oxidation of alcohols to their corresponding carbonyl congeners. Despite its seemingly straightforward nature, this transformative reaction predominantly relies on the use of metals or hazardous reagents, making these processes highly unsustainable. To address this challenge, we have developed a sustainable metal‐free method for the oxidation of alcohols in continuous flow. Using a solid phase hypervalent iodine catalyst and nBu4HSO5 as a phase transfer catalyst and co‐oxidant, primary and secondary alcohols were selectively oxidized to the corresponding carbonyl motifs. This operationally simple continuous‐flow set‐up is highly robust (15 cycles run without significant catalyst leaching or loss of reaction efficiency), uses green solvents, such as acetonitrile or acetic acid, and is readily scalable. [ABSTRACT FROM AUTHOR]

A two-step protocol for the modular synthesis of β2- and α-quaternary β2,2-amino acid derivatives is reported. The key steps are a photocatalytic hydroalkylation reaction, followed by an oxidative functionalisation to access N-protected β-amino acids, esters, and amides. This strategy can be effectively scaled up via continuous-flow technology. [ABSTRACT FROM AUTHOR]

M. Lancaster, M. Roemelt, P. Ettenhuber, Y. Hu, M. W. Ribbe, F. Neese, U. Bergmann, S. DeBeer, Science 2011, 334, 974 - 977; 71 Z. Mathe, O. McCubbin Stepanic, S. Peredkov, S. DeBeer, Chem. Sci. 2021, 12, 7888 - 7901; 72 Y. Pang, N. Nöthling, M. Leutzsch, L. Kang, E. Bill, M. van Gastel, E. Reijerse, R. Goddard, L. Wagner, D. SantaLucia, S. DeBeer, F. Neese, J. Cornella, Science 2023, 380, 1043 - 1048. Rev. 1955, 55, 625 - 657; 13 G. S. Hammond, P. A. Leermakers, N. J. Turro, J. Am. Chem. Soc. 1961, 83, 2396 - 2397; 14 J. Saltiel, G. S. Hammond, J. Am. Chem. Soc. 1963, 85, 2515 - 2516; 15 T. Arai, H. Sakuragi, K. Tokumaru, Chem. Keywords: Bürgenstock Conference; Catalysis; Chemical Biology; Organic Chemistry; Stereochemistry EN Bürgenstock Conference Catalysis Chemical Biology Organic Chemistry Stereochemistry 1 7 7 09/20/23 20230925 NES 230925 Acknowledging the crucial role of stereochemistry in fields as diverse as total synthesis, synthetic methodology, spectroscopy, and the study of the origin of life, the 56th SCS Conference on Stereochemistry, better known as the BÃ1/4rgenstock Conference, brought together a diverse range of chemistry expertise in Brunnen, Switzerland. 83 F. Neese, W. G. Zumft, W. E. Antholine, P. M. H. Kroneck, J. Am. Chem. Soc. 1996, 118, 8692 - 8699; 84 F. Neese, PhD thesis, Universität Konstanz, 1997; 85 F. Neese, Wiley Interdiscip. [Extracted from the article]

Herein, we present a straightforward strategy for the synthesis of fused heterocycles through a deoxygenative, intramolecular Minisci‐type reaction. This approach grants access to complex polycyclic scaffolds in three steps from readily available starting materials, such as chlorinated heteroarenes and 1,3‐diols. The use of saccharide derivatives as the starting 1,3‐diol motif allows for the synthesis of novel heterocyclic scaffolds with excellent diastereoselectivity and formal retention of configuration at the newly formed C−C bond. [ABSTRACT FROM AUTHOR]

Amino acids (AAs) are key structural motifs with widespread applications in organic synthesis, biochemistry, and material sciences. Recently, with the development of milder and more versatile radical‐based procedures, the use of strategies relying on radical chemistry for the synthesis and modification of AAs has gained increased attention, as they allow rapid access to libraries of novel unnatural AAs containing a wide range of structural motifs. In this Minireview, we provide a broad overview of the advancements made in this field during the last decade, focusing on methods for the de novo synthesis of α‐, β‐, and γ‐AAs, as well as for the selective derivatisation of canonical and non‐canonical α‐AAs. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In radical processes involving Selectfluor®, TEDA2+. (N‐(chloromethyl)triethylenediamine) is often generated after an electron or fluorine transfer step. This is a highly reactive species that displays different and unique reactivity when compared to Selectfluor®: It can act as a hydrogen atom transfer (HAT), halogen atom transfer (XAT), or aminating reagent, as well as a powerful single electron oxidant. Despite this versatility, the use of TEDA2+. in synthetic processes remains highly underexplored. This minireview, which covers recent applications of TEDA2+. to promote a wide range of C‐heteroatom and C−C bond formations, aims to highlight the potential of this interesting species in organic chemistry. Particular attention is paid to mechanistic aspects involving how TEDA2+. is generated and the different reactivity patterns that it can display. [ABSTRACT FROM AUTHOR]

The synthesis of tertiary alkyl fluorides through a formal radical deoxyfluorination process is described herein. This light‐mediated, catalyst‐free methodology is fast and broadly applicable allowing for the preparation of C−F bonds from (hetero)benzylic, propargylic, and non‐activated tertiary alcohol derivatives. Preliminary mechanistic studies support that the key step of the reaction is the single‐electron oxidation of cesium oxalates—which are readily available from the corresponding tertiary alcohols—with in situ generated TEDA2+. (TEDA: N‐(chloromethyl)triethylenediamine), a radical cation derived from Selectfluor®. [ABSTRACT FROM AUTHOR]