Streamlining Fluoroalkenyl Arene Synthesis Illuminated with Mechanistic Insights

Fluorinated compounds are a staple of modern-day chemical innovation, and efficient strategies for their synthesis are highly valuable. In this chemical space, fluoroalkenes continue to be the object of much interest across diverse fields, including drug development and pharmaceuticals with active roles as bioisosteres. Herein, in expanding chemists' synthetic toolbox for constructing valuable organofluorine compounds, we report a "pipeline" strategy for the synthesis of fluorinated olefins, viz., gem-difluoroalkenyl and monofluoroalkenyl arenes with high E-isomeric selectivity. The advantages of this streamlined synthetic protocol include mild reaction conditions, operational simplicity, broad substrate scope, and good to excellent yields, even at gram scales. Critical to this robust procedure is the use of widely available and inexpensive "scavenger" solid-support Merrifield peptide resin for removing phosphine impurities. Further computational investigations offering clarity into this reactivity are disclosed.

The Synthesis and Reactivity of Naphthoquinonynes

The first systematic exploration of the synthesis and reactivity of naphthoquinonynes is described. Routes to two regioisomeric Kobayashi-type naphthoquinonyne precursors have been developed, and the reactivity of the ensuing 6,7- and 5,6-aryne intermediates has been investigated. Remarkably, these studies have revealed that a broad range of cycloadditions, nucleophile additions and difunctionalizations can be achieved while maintaining the integrity of the highly sensitive quinone unit. The methodologies offer a powerful diversity oriented approach to C6 and C7 functionalized naphthoquinones, which are typically challenging to access. From a reactivity viewpoint, the study is significant because it demonstrates that aryne-based functionalizations can be utilized strategically in the presence of highly reactive and directly competing functionality.

Pseudocyclic Arylbenziodoxaboroles as Water-Triggered Aryne Precursors in Reactions with Organic Sulfides

Pseudocyclic arylbenziodoxaboroles are unique aryne precursors under neutral aqueous conditions that selectively react with organic sulfides, forming the corresponding sulfonium salts. This reaction is compatible with various substituents (alkyl, halogen, CN, NO2, CHO, and cyclopropyl) in the aromatic ring or alkyl group of the sulfide. Similar reactions of sulfoxides afford o-hydroxy-substituted sulfonium salts. The structures of key products were confirmed by X-ray analysis.

Synthesis, anticancer activity and molecular modeling study of novel substituted triazole linked tetrafluoronaphthalene hybrid derivatives

To create some novel anticancer molecules, a library of novel series of various triazoles linked to the hydroxyl group of 5,6,7,8-tetrafluoronaphthalen-1-ol (3) was designed and synthesized via CuAAC reaction 'Click Chemistry' of tetrafluoronaphthalene based terminal alkyne with substituted organic azides. The structural characterizations of the targeted Click products 9-18 were confirmed by FTIR, 1H NMR, 19F NMR, 13C NMR and HRMS spectroscopy. Synthesized compounds were tested in two triple negative breast cancer (TNBC) cell lines to understand their anticancer potentials. According to our findings, compounds 14 and 13 showed high cytotoxicity in BT549 cells at 20 μM and 30 μM, respectively. Moreover, these compounds blocked the migration of BT549 cells. In the MDA-MB-231 cell line, compound 18 exhibited high cytotoxicity and can block cell migration for 24 h. Molecular docking study with synthesized novel compounds was performed by Glide/SP method against SphK1 drug target. Furthermore, molecular dynamics (MD) simulation was carried out for the compounds 12-14 and 18. The compounds 13 and 14 may be potential inhibitor candidates in place of a reference inhibitor. A pharmacophore model was generated with the most potent compound 14, and the approved drugs were screened using the modules of Discovery Studio to find similar drugs. Consequently, this comprehensive study encompassing design, synthesis, in vitro and in silico analyses were correlated with the structure-activity relationship between compounds. The findings have the potential to unveil promising drug candidates for future studies.Communicated by Ramaswamy H. Sarma.

Synthesis of o-Sulfinylanilines from N-Alkyl Sulfoximines and Arynes

N-Alkyl sulfoximines react with arynes generated in situ under mild conditions providing o-sulfinylanilines in good yields. The transformation is characterized by a broad substrate scope and a good functional group tolerance. The structure of a reaction product was confirmed by single-crystal X-ray diffraction.

Arynes as synthetic linchpins towards the construction of diversely functionalized natural product skeletons

Arynes are a privileged class of reactive intermediates in synthetic organic chemistry, and their unusual reactivities have been the subject of engrossing research interest. Recently, there are many reports on novel aryne-based synthetic innovations as a linchpin approach to accomplish the total synthesis of structurally diverse natural products or their derivatives in a racemic and enantiopure fashion. This review provides an overview of the literature on synthetic strategies, employing arynes as crucial intermediates to construct architecturally intriguing bioactive natural products/derivatives in a period of 2019 to 2022. This study highlights the need to investigate the effective synthesis and search for new biological uses of highly functionalized natural product skeletons.