Copper-Catalyzed Regioselective Annulation of β-Keto Esters and Propargyl Acetates: Access to Polysubstituted Furans

A copper-catalyzed regioselective annulation reaction, conducted without ligands or oxidants, has been developed for the preparation of multisubstituted furans from the readily available starting materials, β-keto esters and propargyl acetates. This process accommodates a wide range of functional groups, resulting in furan skeletons with diverse substitution patterns. The method's potential synthetic utility is highlighted by its applicability in gram-scale preparations and late-stage modifications of natural products.

Ready Access to Densely Substituted Furans Using Tsuji-Wacker-Type Cyclization

A competent method for the construction of highly substituted furans catalyzed by Pd(II) and Cu(II) chloride has been developed. The method provides easy access to di-, tri-, and tetrasubstituted furans from corresponding diols with relatively mild conditions in a unified strategy. The developed method has been successfully tested with more than 25 substrates, which resulted in furans of multiple substitution patterns with up to 84% isolated yields.

Synthesis of Heterobiaryl 4-Aryl Furans through a Base-Promoted Decarboxylative Propargylation/Cycloisomerization Annulation

A transition-metal-free synthesis of heterobiaryl 4-aryl furans through a base-promoted decarboxylative propargylation/cycloisomerization annulation of ethynyl benzoxazinanones and readily accessible β-keto esters or 1,3-diketones has been developed. A series of novel heterobiaryl 4-aryl furans were accessed efficiently in the presence of base under mild reaction conditions. This protocol is significant for probing the reaction mechanism of ethynyl benzoxazinanones and even other propargylic compounds.

Progress and prospects in copper-catalyzed C-H functionalization

Copper-catalyzed C-H functionalization is becoming a significant area in organic chemistry. Copper is now widely used as a catalyst in organic synthesis as it is inexpensive and not very toxic. Functionalization of C-H bonds to construct wide varieties of organic compounds has received much attention in recent times. This review focuses on the recent advances in Cu-catalyzed C-H functionalization and covers literature from 2018-2020.

Synthesis of polysubstituted quinolines through promoter-regulated selective annulation and C–C bond cleavage from 2-styrylanilines and β-keto esters

I₂ and Mn(OAc)₃ regulated annulation of 2-styrylanilines and β-keto esters is accomplished for chemoselective synthesis of 2-alkylquinolines and quinoline-2-carboxylates.

Anticancer Drug Affects Metabolomic Profiles in Multicellular Spheroids: Studies Using Mass Spectrometry Imaging Combined with Machine Learning

Multicellular spheroids (hereinafter referred to as spheroids) are 3D biological models. The metabolomic profiles inside spheroids provide crucial information reflecting the molecular phenotypes and microenvironment of cells. To study the influence of an anticancer drug on the spatially resolved metabolites, spheroids were cultured using HCT-116 colorectal cancer cells, treated with the anticancer drug Irinotecan under a series of time- and concentration-dependent conditions. The Single-probe mass spectrometry imaging (MSI) technique was utilized to conduct the experiments. The MSI data were analyzed using advanced data analysis methods to efficiently extract metabolomic information. Multivariate curve resolution alternating least square (MCR-ALS) was used to decompose each MS image into different components with grouped species. To improve the efficiency of data analysis, both supervised (Random Forest) and unsupervised (cluster large applications (CLARA)) machine learning (ML) methods were employed to cluster MS images according to their metabolomic features. Our results indicate that anticancer drug significantly affected the abundances of a variety of metabolites in different regions of spheroids. This integrated experiment and data analysis approach can facilitate the studies of metabolites in different types of 3D tumor models and tissues and potentially benefit the drug discovery, therapeutic resistance, and other biological research fields.