Metallo-photoredox catalysis has redefined the available bond disconnections in the synthetic arsenal. By harnessing the one-electron chemistry of photoredox catalysis in tandem with low-valent cobalt catalysts, new methods by which functionalities may be stitched together become available. Herein we describe the coupling of photoredox-generated α-amino radical species with conjugated dienes using a unified cobalt and iridium catalytic system in order to access a variety of useful homoallylic amines from simple commercially available starting materials. We present a series of mechanistic experiments that support the intervention of Co-hydride intermediates that undergo diene insertion to generate Co-π-allyl species.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jacs.7b09252 | DOI Listing |
Heliyon
July 2024
Plekhanov Russian University of Economics, Faculty of Trade Economics and Commodity Science, Department of Commodity Science, Stremyanny lane 36, RU 115054, Moscow, Russia.
The impact of thermal treatment for roasting on pine nuts from two geographical regions in Russia (Vladivostok and Baikal) was studied. They were roasted at 180 °C for 20 min in an oven. The aim was to establish the changes that occurred in the chemical (proteins, lipids, carbohydrates, ash, fibers), lipid composition (fatty acids, tocopherols, sterols, phospholipids), and physicochemical characteristics (peroxide value, acid value, iodine value, conjugated dienes and trienes) after roasting of the pine nuts.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana-506004, India.
The optical control of physiological processes with high precision using photoswitches is an emerging strategy for non-invasive diagnosis and therapies, providing innovative solutions to complex biomedical challenges. Light-responsive cyclic conjugated-dienes (cCDs) have long been recognized for their 4π-photocyclization; however, photoswitching behaviour in medium-sized cCDs has recently been reported, representing a pioneering discovery in the field. Reinforced by previous experimental evidence corroborating the Woodward-Hoffmann rules, this report provides insight into the origin of the exotic dual photoexcitation mechanism devised to achieve thermo-reversible photoswitching in large cCDs with cyclodeca-1,3-diene as a prototype.
View Article and Find Full Text PDFMolecules
December 2024
Department of Physical Chemistry, Faculty of Chemistry, University of Łódź, Pomorska 163/165, 90-236 Łódź, Poland.
Extracts from natural waste like bark or leaves are great sources of phytochemicals, which contain functional groups (hydroxyl, carboxylic, vinyl, allyl) attractive in terms of polymer synthesis. In this study, the synthesis of epoxy with an extract of Scots pine bark as a natural co-hardener was evaluated. Ultraviolet-visible (UV-Vis) spectroscopy was used for the identification of phytochemicals with conjugated dienes and quantification of TPC.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States.
What if an experiment could combine the power of cycloaddition and cross-coupling with the formation of an aromatic molecule in a single collision? Crossed molecular beam experiments augmented with electronic structure and statistical calculations provided compelling evidence on a novel radical route involving 1,3-butadiynyl (HCCCC; X∑) radicals synthesizing (substituted) arylacetylenes in the gas phase upon reactions with 1,3-butadiene (CHCHCHCH; XA) and 2-methyl-1,3-butadiene (isoprene; CHC(CH)CHCH; XA'). This elegant mechanism merges two previously disconnected concepts of cross-coupling and cycloaddition-aromatization in a single collision event via the formation of two new C(sp)-C(sp) bonds and bending the 180° moiety of the linear 1,3-butadiynyl radical out of the ordinary by 60° to 120°. In addition to its importance to fundamental organic chemistry, this unconventional mechanism links two previously separated routes of gas-phase molecular mass growth processes of polyacetylenes and polycyclic aromatic hydrocarbons (PAHs), respectively, in low-temperature environments such as in cold molecular clouds like the Taurus Molecular Cloud (TMC-1) and in hydrocarbon-rich atmospheres of planets and their moons such as Titan, which revises the established understanding of low-temperature molecular mass growth processes in the Universe.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Clinical Chemistry, Medical University of Gdańsk, 80-211 Gdańsk, Poland.
Oxidative modifications of lipoproteins play a crucial role in the initiation of atherosclerotic cardiovascular diseases (ASCVDs). Nowadays, the one effective strategy for the treatment of patients with hyperlipoproteinemia(a) is lipoprotein apheresis (LA), which has a pleiotropic effect on reducing the risk of ASCVDs. The significance of oxidative susceptibility of the LDL fraction in ASCVDs has been extensively studied.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!