Similar Publications

A new humic acid-based nanomagnetic copper(II) composite was prepared and used as an eco-friendly recoverable catalyst for synthesizing 1,4-disubstituted 1,2,3-triazoles. The synthesis was done via the three-component click reaction of alkyl halide, sodium azide, and terminal alkyne with good to excellent yield. A simple magnetic copper acetate composite, FeO@HA-Cu(OAc), was prepared using humic acid and characterized by SEM, TEM, XRD, EDX, EDS-mapping, VSM, TGA, AAS, and FT-IR.

View Article and Find Full Text PDF

Tambjamines are complex bipyrrole-containing natural products that possess promising bioactive properties. Although is known to produce both cyclic tambjamine MYP1 and the linear precursor (YP1), the biosynthetic machinery used to catalyze the site-selective oxidative carbocyclization at the unactivated 1° carbon of YP1 has remained unclear. Here, we demonstrate that a three-component Rieske system consisting of an oxygenase (TamC) and two redox partner proteins is responsible for this unprecedented activity on YP1 and potentially, a non-native substrate (BE-18591).

View Article and Find Full Text PDF

Multicomponent reactions (MCRs), highly sought-after methods to produce atom-, step-, and energy-economic organic syntheses, have been developed extensively. However, catalytic asymmetric MCRs, especially those involving radical species, remain largely unexplored owing to the difficulty in stereoselectively regulating the extraordinarily high reactivity of open-shell radical species. Herein, we report a conceptually novel catalytic asymmetric three-component radical cascade reaction of readily accessible glycine esters, α-bromo carbonyl compounds and 2-vinylcyclopropyl ketones via synergistic photoredox/Brønsted acid catalysis, in which three sequential C-C (σ/π/σ) bond-forming events occurred through a radical addition/ring-opening/radical-radical coupling protocol, affording an array of valuable enantioenriched unnatural α-amino acid derivatives bearing two contiguous stereogenic centers and an alkene moiety in moderate to good yield with high diastereoselectivity, excellent enantioselectivity and good -dominated geometry under mild reaction conditions.

View Article and Find Full Text PDF

From Radical Coupling to Enantioselective Controlled Protonation: Advancing Precise Construction of Stereocenters.

J Am Chem Soc

January 2025

Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, Henan 475004, PR China.

Recent advancements in green and sustainable platforms, particularly visible light-driven photocatalysis, have spurred significant progress in radical chemistry, enabling the efficient synthesis of important molecules from simple and readily available feedstocks under mild conditions. However, the rapid orbital flipping and high reactivity of radicals pose substantial challenges for achieving precise enantiocontrol in stereocenter formation via radical coupling. In this study, we present a generic and efficient strategy that modulates this elusive approach, facilitating enantiocontrollable protonation through 1,3-boron migration.

View Article and Find Full Text PDF

Photoredox-Catalyzed Three-Component Sulfonaminoalkynylation of Alkenes via a Radial/Polar Crossover.

J Org Chem

January 2025

School of Pharmaceutical Science, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China.

We report a photoredox-catalyzed three-component sulfonaminoalkynylation of alkenes with -aminopyridine salts and potassium alkynyltrifluoroborate salts. This aminoalkylation reaction underwent a radial/polar crossover mechanism, which was distinguished from the previous reports. A variety of β-alkynylated sulfonamides were obtained in moderate to excellent yields.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!