Development of an Efficient Synthetic Process for Irisquinone
Synlett DOI: 10.1055/s-0042-1751560 Irisquinone is a tumor radiotherapy sensitizer and has been found to have broad-spectrum antitumor activity in recent years. The current acquisition method of extracting and purifying from semen irisis has greatly limited its wide application and activity study deeply. In this work an efficient route for the synthesis of the irisquinone was investigated to solve the source of it. The target compound was synthesized by 5-step reactions to Wittig reaction, reduction, oxidation, Wittig reaction, and oxidation using 3,5-dimethoxycarboxaldehyde as the starting material with an overall yield o...
Source: Synlett - February 16, 2024 Category: Chemistry Authors: Zheng, Kun Zhang, Qifeng Ma, Yuheng Liang, Guodong Zhao, Yan Ga, Lu Tags: letter Source Type: research
Palladium-Catalyzed α-Arylation of Meyers’s Chiral Bicyclic Lactams and a Deprotonative Ring-Opening Sideline
Synlett DOI: 10.1055/a-2258-3788 Described is a deprotonative α-arylation reaction of Meyers’s chiral bicyclic lactams (MCBLs) under palladium catalysis, and a substrate-dependent post-transformation. When the bridgehead carbon of the MCBLs is substituted with a methyl or an ethyl group, the initial arylation product undergoes a further rearrangement reaction to give a conjugated framework. On the other hand, substrates bearing a bridgehead isopropyl or aryl group are converted into the corresponding exo-arylation products. Preliminary studies indicated that the rearrangement pathway was promoted by deprotonation and wa...
Source: Synlett - February 16, 2024 Category: Chemistry Authors: Chiang, Hsin-Lun Zhao, Wei-Ting Chen, Yi-An Lin, Yi-Ching Chen, Pei-Lin Wu, Yen-Ku Tags: letter Source Type: research
Small-Molecule Activation by Low-Coordinated Germanium Compounds
Synlett DOI: 10.1055/a-2245-6718 We have been interested in the differences between the properties of low-coordinated carbon compounds and their heavier homologues based on elements of group 14, e.g., Si and Ge. Fundamental research on the synthesis and characterization of divalent and multiply bonded compounds of heavier group 14 elements has led to a variety of isolated low-coordinated species of heavier group 14 elements that can replace transition metals in small-molecule transformations. We have focused on low-coordinated germanium compounds with double or triple bonds between germanium atoms, as well as germanium-con...
Source: Synlett - February 16, 2024 Category: Chemistry Authors: Sasamori, Takahiro Tags: account Source Type: research
Harnessing the Power of C –H Functionalization Chemistry to Accelerate Drug Discovery
Conclusions [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - February 16, 2024 Category: Chemistry Authors: Li, Bing Tyagarajan, Sriram Dykstra, Kevin D. Cernak, Tim Vachal, Petr Krska, Shane W. Tags: account Source Type: research
Chemical Synthesis and Antitumor Evaluation of Chikusetsusaponin IVa Butyl Ester and Its Analogues
Synlett DOI: 10.1055/a-2239-6717 Chikusetsusaponin IVa butyl ester (CS-IVa-Be) is a triterpene saponin that acts as a novel IL6R antagonist for inducing breast cancer cell apoptosis. However, the structure–activity relationship for this class of saponins remains unclear. Here, we report a gram-scale synthesis of CS-IVa-Be and the efficient preparation of eight of its analogues. CS-IVa-Be was demonstrated to have significant antitumor activities against MDA-MB-231, HepG2, and A549 cells. When one of the sugar residues at either the 3-OH or 28-COOH position of CS-IVa-Be was cleaved, or the length of the alkyl chain on the ...
Source: Synlett - February 15, 2024 Category: Chemistry Authors: Zheng, Jibin Wang, Yanxiao Zhang, Yiyue Rong, Jingjing He, Dongjuan Wang, Xiaotong Zhang, Liangliang Xu, Jianguang Cao, Peng Yang, You Tags: letter Source Type: research
Photocatalytic Carbamoyl Radical Transfer to Alkenyl Azaarenes
Synlett DOI: 10.1055/a-2256-3096 1-Phenyl-3-azaarenyl-propan-1-amine structural moieties have been widely incorporated in pharmaceuticals and biologically active compounds; however, current synthetic methods to access these compounds need multiple steps and proceed with low efficiency. Herein, we reported an efficient photocatalytic carbamoyl radical transfer approach that allows the preparation of these compounds in high yields (up to 88%). The reaction easily runs on a gram-scale and was applied for the preparation of pheniramine in two steps with 72% total yield. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 St...
Source: Synlett - February 15, 2024 Category: Chemistry Authors: Yu, Zi-xuan Ma, Shi-Wei Li, Guang-xun Ma, Long-jun Tags: letter Source Type: research
N-Heterocyclic Carbene Catalysis for Facile Access to Pentasubstituted 4H-Pyran Derivatives
We report an N-heterocyclic carbene-catalyzed [3+3] annulation reaction of β-ketone esters with enynals for rapid access to pentasubstituted 4H-pyran derivatives through a regioselective activation of the ynal. A series of 4H-pyran derivatives bearing various substituents were obtained in moderate to excellent yields. This method could find further applications in the synthesis of structurally diverse 4H-pyran-derived functional molecules from readily available starting materials. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  | ...
Source: Synlett - February 15, 2024 Category: Chemistry Authors: Peng, Xiaolin Wang, Yulin Huang, Yixian Zhang, Sheng Jin, Zhichao Ren, Shi-Chao Tags: letter Source Type: research
Regioselective Aldehyde Decarbonylation through Palladium-Catalyzed Nitrile Boronic Acid Cross-Coupling
Synlett DOI: 10.1055/s-0042-1751562 Aldehyde decarbonylation is a vital chemical transformation in the synthesis of natural products. Nature accomplishes this process through a family of decarbonylase enzymes, while in the laboratory, harsh transition metals and elevated temperatures are required. Herein, we report a mild aldehyde decarbonylation reaction that exhibits exclusive selectivity for ortho-aldehydes during a tandem nitrile boronic acid cross-coupling reaction. A wide substrate scope is displayed that includes regioselective removal of the ortho-aldehyde from phenyl boronic acids in the presence of meta- or para-...
Source: Synlett - February 14, 2024 Category: Chemistry Authors: Paikin, Zachary E. Talbott, John M. Raj, Monika Tags: letter Source Type: research
Adventures in Coumarin Chemistry
Conclusions [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - February 14, 2024 Category: Chemistry Authors: Langer, Peter Tags: account Source Type: research
Synform issue 2024/03
Synlett 2024; 35: A36-A52 DOI: 10.1055/s-0040-1720626 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - February 14, 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-0043-1763680 Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - February 14, 2024 Category: Chemistry Tags: table of contents Source Type: research
Synthesis and α-Functionalisation of Cyclic Imines
Synlett DOI: 10.1055/a-2251-4145 α-Functionalisation of cyclic imines is explored. The cyclic imine substrates are synthesised from their respective halonitrile precursors using a nucleophilic addition/cyclisation sequence. Selective monohalogenation of the cyclic imines yields α-haloimines, which serve as a platform to obtain various α-hydroxyimine derivatives. In addition, an unusual tautomerisation and oxidation sequence is observed in the attempted preparation of α-hydroxyimines. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  AbstractÂ...
Source: Synlett - February 13, 2024 Category: Chemistry Authors: Kuang, Ze Ding, Xiao-Bo Furkert, Daniel P. Brimble, Margaret A. Tags: letter Source Type: research
Applications of Quantum Chemistry in Biomimetic Syntheses of Polycyclic Furanocembrane Derivatives
Conclusion [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - February 12, 2024 Category: Chemistry Authors: Wang, Di Zhou, Tao Ren, Jianfeng Hirst, Jonathan D. Gao, Zhanghua Tang, Bencan Tags: account Source Type: research
Palladium-Catalyzed Carbothiolation by Using Thioesters with Formation of a Quaternary Carbon
Synlett DOI: 10.1055/a-2248-3205 A Pd-catalyzed carbothiolation using thioesters, with the formation of a quaternary carbon, is described. Carbothiolation using thioesters was problematic due to a direct-coupling side reaction that produced a sulfide, but this side reaction was successfully suppressed by an appropriate selection of the thioester and the reaction conditions. In the preparation of chroman or coumaran derivatives by this method, the reaction using S-phenyl 4-methoxybenzenecarbothioate Pd(PPh3)4, and Cs2CO3 at 100 °C in toluene afforded the desired products in good yields (77–92%). The carbothiolation react...
Source: Synlett - February 9, 2024 Category: Chemistry Authors: Okura, Yoshifumi Ito, Ryunosuke Kumazawa, Hyu Nakada, Masahisa Tags: letter Source Type: research
Aromatic Amine Catalysts for the O2-Mediated Cross-Dehydrogenative Phenothiazination Reaction?
In this study, we investigated a series of aromatic amines and their potential redox catalytic activity, in particular compared to our previously reported amino-Te(II) catalysts. The O2-mediated cross-dehydrogenative phenothiazination of phenols was utilized as a benchmark test reaction, as well as the O2-mediated cross-dehydrogenative coupling of indoles. We thus identified a proton sponge as an effective aromatic amine redox catalyst. It was moreover found that although the proton sponge displays clear catalytic activity, it is generally less active than previously reported phenotellurazine catalysts. The insights provid...
Source: Synlett - February 9, 2024 Category: Chemistry Authors: Nandi, Shiny Paffen, Alina Patureau, Frederic W. Tags: letter Source Type: research
