Synthesis of Axially Chiral Bibenzo[g]coumarin Derivatives by Rhodium-Catalyzed Oxidative Annulation of Thiocarbamates
We report a two-step synthesis of binaphthyl-fused chiral bibenzo[g]coumarin derivatives by Rh-catalyzed annulative coupling reaction of BINOL-based thiocarbamates with alkynes. The optical properties of the coupling products were evaluated. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Takishima, Ryo Ghosh, Koushik Nishii, Yuji Miura, Masahiro Tags: letter Source Type: research
Silver Nitrate Catalyzed Sulfonylation of O-Propargyl Alkynes
Synlett DOI: 10.1055/a-2205-5806 The development of new catalytic methods based on lower-cost metals under environmentally friendly conditions is still a challenge. Herein, we report an efficient strategy for the synthesis of vinyl sulfones from O-propargyl alkynes and sodium salts of sulfinic acids using silver nitrate, an inexpensive and readily available catalyst, under air atmosphere using aqueous conditions. The products were obtained in good to moderate yields, and the mechanism of the reaction was also investigated. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals:...
Source: Synlett - December 14, 2023 Category: Chemistry Authors: S átiro, Bárbara G. Moura, Igor M. R. Almeida, Cl áudia L. A. Freitas, Queila P. B. Oliveira, Roberta A. Menezes, Paulo H. Tags: letter Source Type: research
Facilitated Synthetic Access to Boronic Acid-Modified Nucleoside Triphosphates and Compatibility with Enzymatic DNA Synthesis
Synlett DOI: 10.1055/a-2212-7704 Decorating nucleic acids with boronic acids can extend the usefulness of oligonucleotide-based tools to the development of medical imaging agents, the promotion of binding of aptamers to markedly more challenging targets, or the detection of (poly)saccharides. However, due to the hygroscopic nature and high intrinsic reactivity of boronic acids, protocols for their introduction into nucleic acids are scarce. Here, we have explored various synthetic routes for the crafting of nucleoside triphosphates equipped with phenylboronic acids. Strain-promoted azide–alkyne cycloaddition appears to b...
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Niogret, Germain R öthlisberger, Pascal Levi-Acobas, Fabienne Bonhomme, Fr édéric Gasser, Gilles Hollenstein, Marcel Tags: letter Source Type: research
Acylative and Silylative Dynamic Kinetic Resolutions of 6-Hydroxy-2H-pyran-3(6H)-one Catalyzed by Chiral Guanidines
Synlett DOI: 10.1055/a-2206-7545 Chiral guanidine-catalyzed acylative and silylative dynamic kinetic resolutions of 6-hydroxy-2H-pyran-3(6H)-one were achieved. We succeeded in developing a non-enzymatic acylative dynamic kinetic resolution of 6-hydroxy-2H-pyran-3(6H)-one with high enantioselectivity, which could be improved by recrystallization. In contrast, the non-enzymatic silylative dynamic kinetic resolution of 6-hydroxy-2H-pyran-3(6H)-one was accomplished with a moderate selectivity for the first time. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of conte...
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Miyazaki, Kanako Nakata, Kenya Tags: letter Source Type: research
Rhodium-Catalyzed Direct Vinylene Annulation of 2-Aryloxazolines and Cascade Ring-Opening Using a Vinyl Selenone
We report a Rh(III)-catalyzed annulation and ring-opening cascade reaction with 2-aryloxazolines. By utilizing a vinyl selenone as an oxidizing acetylene surrogate, the target three-component coupling products were obtained in high yields without using a stoichiometric amount of external oxidant. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Kitano, Junya Nishii, Yuji Hirano, Koji Miura, Masahiro Tags: letter Source Type: research
Chiral Bifunctional NHC –Guanidine Ligands for Asymmetric Hydrogenation
We report the synthesis of chiral N-heterocyclic carbene/guanidine bifunctional ligands from readily available amino alcohols. The resulting chiral bifunctional copper(I) complexes are active catalysts in an asymmetric hydrogenation of ketones. We show that the chiral linker unit can be employed for the transfer of stereoinformation. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Gorai, Mahadeb Teichert, Johannes F. Tags: letter Source Type: research
Enantioselective (3+2)-Annulation of β-Keto Esters with Azoalkenes towards Bicyclic Dihydropyrroles via Cooperative Palladium and Brønsted Acid Catalysis
Synlett DOI: 10.1055/a-2210-0973 A cooperative catalytic process through palladium and Brønsted acid activation is developed for the conjugate addition of cyclic β-keto esters to azoalkenes directly followed by hemiaminal formation upon cyclization. This transformation is enabled by utilizing chiral Pd-aqua complexes as combined Brønsted acid–base catalysts. Thus, bicyclic and highly functionalized dihydropyrroles with two contiguous quaternary stereogenic centers are formed in excellent yields as single diastereomers and with exceptional enantioselectivity. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stutt...
Source: Synlett - December 14, 2023 Category: Chemistry Authors: Friedmann, Till Mireles-Ch ávez, Daniel A. Walter, Frederik L. Schneider, Christoph Tags: letter Source Type: research
Bidentate Lewis Acid-Catalyzed Inverse Electron-Demand Diels –Alder Reaction of Phthalazines and Cyclooctynes
Synlett DOI: 10.1055/a-2204-9522 Herein we report a method for facilitating the inverse-electron-demand Diels–Alder reaction of 1,2-diazines and cyclooctynes by utilizing a boron-based bidentate Lewis acid catalyst. Readily available electron-deficient and electron-rich phthalazines proved to be suitable substrates in this transformation. The described method enables the facile construction of diversely substituted polycyclic aromatic hydrocarbons fused to eight-membered carbocycles. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract Â...
Source: Synlett - December 13, 2023 Category: Chemistry Authors: Gro ße, Michel Wegner, Hermann A. Tags: letter Source Type: research
Hydrogen Sulfate-Templated Synthesis of a Bis-Ferrocene Macrocycle
Synlett DOI: 10.1055/s-0043-1763628 A bis-ferrocene macrocycle was synthesized by reversible acylhydrazone formation under thermodynamic control, starting from a ferrocene functionalized with hydrazide and protected aldehyde moieties. A hydrogen sulfate anion acts as a template to direct the synthesis specifically toward the macrocyclic dimer, due to a weak but selective binding interaction. This work highlights the utility of dynamic combinatorial chemistry as an approach to macrocycle synthesis. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  | Â...
Source: Synlett - December 13, 2023 Category: Chemistry Authors: Beeren, Sophie R. Tags: letter Source Type: research
Erratum - A Simplified Protocol for Large-Scale Preparation of 4CzIPN and 3DPA2FBN
Synlett DOI: 10.1055/s-0043-1763661 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Full text (Source: Synlett)
Source: Synlett - December 13, 2023 Category: Chemistry Authors: Zhang, Yongda Lei, Zhen Xu, Yibo Kosnik, Stephanie C. Jiang, Qi Tags: errata Source Type: research
Triisobutylaluminium-Mediated Regioselective Protection of Sterically Hindered Amide NH of Cyclo-(AA-Gly): Key Building Block for Next-Generation Peptide Synthesis
In this study, we address the challenge of regioselective Boc protection in the more sterically hindered amide NH of unsymmetrical 2,5-diketopiperazines (DKPs) formed from glycine and various amino acids. Our research introduces a novel technique utilizing cost-effective triisobutylaluminium and trimethoxysilane. Notably, trimethoxysilane selectively reacts with the less hindered amide NH, facilitating the regioselective Boc protection of the more congested amide NH in DKPs. The primary objective of our work is to develop a straightforward and scalable approach for the synthesis of Boc-protected DKPs, with a focus on addre...
Source: Synlett - December 12, 2023 Category: Chemistry Authors: Ramakrishna, Isai Hattori, Tomohiro Ishiguro, Tomomi Yamamoto, Hisashi Tags: letter Source Type: research
Editorial
Synlett 2024; 35: III-V DOI: 10.1055/s-0043-1763659 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - December 8, 2023 Category: Chemistry Tags: Editorial Source Type: research
Chemoselective Reduction of Barbiturates by Photochemically Excited Flavin Catalysts
Synlett DOI: 10.1055/a-2201-7141 Photocatalytic reductive cyclizations are powerful methods for obtaining structurally complex molecules. Achieving noninherent reactivity in substrates with more than one potential site of reduction is a difficult challenge. We disclose the use of flavin catalysis for the chemoselective reductive cyclization of barbiturates with additional reactive functional groups. Our method provides orthogonal selectivity in comparison to the well-established reductant samarium(II) iodide, which preferentially reduces substrate ketone groups. Flavin catalysis first leads to barbiturate reduction and all...
Source: Synlett - December 8, 2023 Category: Chemistry Authors: Foja, Richard Walter, Alexandra Storch, Golo Tags: letter Source Type: research
Cluster Preface: Functional Dyes
Synlett 2024; 35: 1-2 DOI: 10.1055/s-0043-1763657
Youjun Yang (left) received his BS (2002) from the University of Science and Technology of China, and his PhD (2007) with Prof. Robert M. Strongin at Louisiana State University. Then, he joined the Anslyn group at UT Austin as a postdoc. In 2010, he joined the faculty of the school of pharmacy, East China University of Science and Technology (ECUST). His research interests include NIR fluorescent dyes, photo-responsive dyes, and fluorescent molecular probes.
Jiangli Fan (right) obtained her PhD at Dalian University of Technology (2005). Now she is a Professor a...
Source: Synlett - December 8, 2023 Category: Chemistry Authors: Yang, Youjun Fan, Jiangli Tags: cluster Source Type: research
Synform issue 2023/12
Synlett 2024; 35: A1-A21 DOI: 10.1055/s-0040-1720618 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - December 8, 2023 Category: Chemistry Authors: Zanda, Matteo Tags: Synform Source Type: research
