Br ønsted Acid Catalyzed Intramolecular Allylic Substitution Reaction of Allylic Alcohols: A Facile Synthesis of 2-Vinylchromans
Synlett DOI: 10.1055/a-2301-9223 Brønsted acid catalyzed intramolecular allylic substitution reaction of secondary and tertiary allylic alcohols has been developed. A variety of 2-vinylchromans were efficiently prepared in moderate to excellent yields. The given method features wide substrate scope, operational simplicity, and mild, metal-free reaction conditions. The practicability of the method was demonstrated by a gram-scale reaction and further derivations of the product. Preliminarily studies on a catalytic asymmetric reaction were also undertaken. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Ge...
Source: Synlett - April 25, 2024 Category: Chemistry Authors: Li, Yun-Fan Xi, Yu-Ting Hu, Kai-Ji Tan, Qitao Ding, Chang-Hua Xu, Bin Tags: letter Source Type: research
Tripeptide-Catalyzed Asymmetric Michael Addition Reaction of β-Nitrostyrenes with Cyclohexanone
Synlett DOI: 10.1055/a-2307-0645 A tripeptide catalyst derived from natural l-amino acids was employed in the reaction of β-nitrostyrenes with cyclohexanone, serving as a model for the asymmetric Michael addition reaction. The reaction was conducted in the presence of H-Pro-Tle-Gly-OH and 2-fluoro-4-chlorobenzoic acid as co-catalysts (each at 20 mol%) in DMF-H2O (5:1) at 0 °C for 3 days. This process yielded the desired Michael adducts with excellent efficiency and good stereoselectivity (up to 98% yield, up to 92% ee). [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: ...
Source: Synlett - April 25, 2024 Category: Chemistry Authors: Kippei, Maeda Takeyama, Mitsuki Kohari, Yoshihito Murata, Miki Tags: letter Source Type: research
Iron-Catalyzed Oxidative C(sp3) –C(sp3) Radical Coupling Reaction between Thiohydantoins and O-Acetyloximes for the Synthesis of 1,3-Dibenzyl-3,4-dihydropyrrolo[2,3-d]imidazole-2(1H)-thione Derivatives
Synlett DOI: 10.1055/a-2302-0450 A unified heteroannelation method to achieve the synthesis of 1,3-dibenzyl-3,4-dihydropyrrolo[2,3-d]imidazole-2(1H)-thione derivatives with an iron catalyst is proposed. The annelation reaction follows a C(sp3)–C(sp3) radical coupling between a thiohydantoin and an O-acetyloxime. The synthetic approach enables access to several alkynylated thiohydantoins and O-acetyloximes with controlled selectivity toward C(sp3)–C(sp3) coupling rather than C(sp3)–C(sp3)–O coupling in moderate to high yields. An optimization study has been carried out by changing the catalyst loading, oxidants, sol...
Source: Synlett - April 24, 2024 Category: Chemistry Authors: Patel, Parth P. Chikhalia, Kishor H. Tags: letter Source Type: research
Introduction of an N-Amino Group onto 4-(Tetrazol-5-yl)-5-nitro-1,2,3-triazole: A Strategy for Enhancing the Density and Performance of Energetic Materials
Synlett DOI: 10.1055/a-2298-0282 2-Amino-5-nitro-4-(tetrazol-5-yl)-1,2,3-triazole (HANTT), its corresponding energetic salts and a dimeric azo compound are successfully synthesized. Compared to 5-nitro-4-(tetrazol-5-yl)-1,2,3-triazole (H2NTT), the neutral N-amino compound HANTT exhibits excellent properties in many aspects, including a higher density (ρ = 1.86 g cm–3), a better detonation performance (D
v = 8931 m s–1, P = 32.2 GPa) and a higher thermal decomposition temperature (T
d = 237 °C). Among the prepared materials, the hydroxylammonium energetic salt exhibits the best detonation performance (D
...
Source: Synlett - April 24, 2024 Category: Chemistry Authors: Huang, Xun Zhao, Pinxu Huang, Haifeng Yang, Jun Tags: letter Source Type: research
A Facile Procedure for Halodecarboxylation of Hydroxyaromatic Carboxylic Acids
Synlett DOI: 10.1055/a-2294-4029 An efficient approach is reported for the direct halodecarboxylation of hydroxyaromatic acids by using a readily available N-halosuccinimide (halo = Cl, Br) as the sole promoter in ethanol at room temperature without any other catalyst or additive. This environmentally friendly route tolerates a wide substrate scope with good to excellent yields under convenient conditions. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - April 23, 2024 Category: Chemistry Authors: Zhang, Zhenbei Sun, Wenhui Cao, Zhishan Zhang, Guisheng Bakumenko, Olha Xue, Feng Tags: letter Source Type: research
Triton B Catalyzed Rapid and Mild Synthetic Protocol for both Henry Reaction of Isatin and Michael Reaction of Chalcone with Nitroalkane
Synlett DOI: 10.1055/s-0043-1774862 A highly efficient and general synthetic protocol for both Henry and Michael reactions was developed using metal-free catalyst Triton B (benzyltrimethylammonium hydroxide) and isatins and chalcones, respectively. This methodology is inexpensive, the reagents are easy to handle, and the approach offers wide functional group tolerance of isatins and chalcones. The base catalyst Triton B is less toxic, recyclable, and reusable. This efficient method reduces reaction times, minimizes reagent excess, avoids chromatography, and is aligned with sustainable chemistry principles, offering eco-fri...
Source: Synlett - April 23, 2024 Category: Chemistry Authors: Talukdar, Mrinal Islam, Nasreen Mishra, Akanksha Dave, Alpa Y Begari, Eeshwaraiah Tags: letter Source Type: research
A Personal Account from Inside Keith Fagnou ’s Research Laboratory
Synlett 2024; 35: 833-839 DOI: 10.1055/s-0043-1774827 [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - April 23, 2024 Category: Chemistry Authors: Campeau, Louis-Charles Tags: cluster Source Type: research
Synform issue 2024/05
Synlett 2024; 35: A70-A86 DOI: 10.1055/s-0040-1720631 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - April 23, 2024 Category: Chemistry Authors: Zanda, Matteo Tags: Synform Source Type: research
Linked PDF of Table of Contents
Synlett 2024; 35: V- DOI: 10.1055/s-0043-1774859 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - April 23, 2024 Category: Chemistry Tags: table of contents Source Type: research
An Improved Iodine-Catalyzed Aromatization Reaction and Its Application in the Synthesis of a Key Intermediate of Cannabidiol
In this study, the development of an improved process for the synthesis of a key cannabidiol intermediate, methyl olivetolate, is described. The process involves an improvement of the iodine-catalyzed aromatization of cyclohexanone using potassium persulfate as an oxidant. This approach enabled for the efficient synthesis of methyl olivetolate with a 90% yield and 99.84% HPLC purity on a 5 kg scale. Additionally, a total of 19 cyclohexanone substrates afforded higher yields (71–92%) of m-diphenol compounds compared to the established methods. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticl...
Source: Synlett - April 22, 2024 Category: Chemistry Authors: Abduahadi, Safomuddin Mintah Bonku, Emmanuel Qin, Hongjian Odilov, Abdullajon Zhu, Fuqiang Aisa, Haji Akber Shen, Jingshan Tags: letter Source Type: research
Advances in the Synthesis of Sulfur-Containing Cyclic Architectures via Insertion of SO2
Conclusion [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - April 22, 2024 Category: Chemistry Authors: Lu, Xi Huang, Yuyang Yang, Yuxing Shu, Chao Tags: account Source Type: research
Microwave-Assisted Transfer Hydrogenation of Carbonyl and Nitro Compounds Using Bimetallic Ru(II) Cymene Complexes
We report an investigation of the microwave-assisted catalytic transfer hydrogenation (TH) of carbonyl and nitro compounds by employing Ru(II) complexes: bimetallic [(p-cymene)2(RuCl)2L1]2X (X = BF4 (Cat2); X = PF6 (Cat3)) and mononuclear [(p-cymene)(RuCl)L2]BF4 (Cat4) (where L1 = N,N′-(3,3′,5,5′-tetraisopropyl-[1,1′-biphenyl]-4,4′-diyl)bis(1-(pyridin-2-yl)methanimine) and L2 = N-(2,6-diisopropylphenyl)-1-(pyridin-2-yl)methanimine). At a low catalyst loading of 0.01 mol% (Cat2/Cat3), a broad range of substrates, comprising aromatic as well as aliphatic ketones and aldehydes, undergo the TH reaction in a short rea...
Source: Synlett - April 19, 2024 Category: Chemistry Authors: Deshmukh, Gopal Murugavel, Ramaswamy Tags: letter Source Type: research
AgSCF3 Radical Addition Based on an Oxidant-Free α,β-Amide (Trifluoromethyl)sulfanylation Reaction
Synlett DOI: 10.1055/s-0043-1763759 (Trifluoromethyl)sulfanylamides are an important class of organic compounds that are common among natural products and drug molecules. Here, we report a (trifluoromethyl)sulfanylation reaction using silver(I) (trifluoromethyl)sulfide as a free-radical (trifluoromethyl)sulfanylation reagent for β-amide compounds. This reaction does not require stoichiometric oxidants or additional transition-metal catalysts, and can be achieved by adding common organic acids. This method has excellent applicability and can accommodate several functional groups, including ester groups, acyl groups, and ev...
Source: Synlett - April 18, 2024 Category: Chemistry Authors: Li, Zhi-Bo Zhang, Jin Shi, Yi-Ran Li, Hong Yang, Min-Ge Zhu, Wen-Qing Fan, Qiang-Wei Li, Yang Tags: letter Source Type: research
Stereocontrolled Synthesis of a Heptose- and Kdo-Containing Common Inner-Core Trisaccharide of Lipopolysaccharides from Multiple Pathogenic Bacteria
We report an efficient stereocontrolled approach for the synthesis of a common inner-core trisaccharide containing difficult-to-access, rare, higher-carbon sugars: a heptose (Hep) and 3-deoxy-α-d-manno-oct-2-ulosonic acid (Kdo). Key features include comprehensive elaboration of a practical synthesis of versatile Hep and Kdo building blocks, and stereoselective assembly of an inner-core trisaccharide from multiple pathogenic bacteria. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - April 18, 2024 Category: Chemistry Authors: Li, Jiawei Gao, Runing Hao, Tianhui Li, Tiehai Tags: letter Source Type: research
Copper-Catalyzed [4+1] and [4+2] Reactions through Tandem Remote Propargylation/Cyclization/Isomerization with an Amine or a Hydrazine
Synlett DOI: 10.1055/a-2294-5395 Two novel copper-catalyzed cyclization reactions involving a remote propargylic substitution/cyclization/isomerization cascade are disclosed. Derivatives of the seldomly studied heterocycles thieno[2,3-c]pyrrole and thieno[2,3-d]pyridazine are conveniently synthesized in moderate to good yields from primary amines or arylhydrazines through [4+1] and [4+2] reactions, respectively. Preliminary mechanistic experiments corroborated the occurrence of the designed cascade reactions. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of cont...
Source: Synlett - April 15, 2024 Category: Chemistry Authors: Sun, Yu-Ze Lin, Guo-Qiang He, Zhi-Tao Tags: letter Source Type: research
