Intermolecular Organophotocatalytic Cyclopropanation of Unactivated Olefins

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(2), С. 774 - 780

Опубликована: Янв. 6, 2023

Intermolecular cyclopropanation of mono-, di-, and trisubstituted olefins with α-bromo-β-ketoesters α-bromomalonates under organophotocatalysis is reported. The reaction displays broad functional group tolerance, including substrates bearing acids, alcohols, halides, ethers, ketones, nitriles, esters, amides, carbamates, silanes, stannanes, boronic as well arenes, furnishes highly substituted cyclopropanes. transformation may be performed in the presence air moisture 0.5 mol % a benzothiazinoquinoxaline organophotocatalyst. Mechanistic investigations, involving Stern–Volmer quenching, quantum yield determination, deuteration experiments, are carried out, catalytic cycle for discussed.

Язык: Английский

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Photocatalyzed Enantioselective Functionalization of C(sp³)–H Bonds

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(2), С. 1209 - 1223

Опубликована: Янв. 3, 2024

Owing to its diverse activation processes including single-electron transfer (SET) and hydrogen-atom (HAT), visible-light photocatalysis has emerged as a sustainable efficient platform for organic synthesis. These provide powerful avenue the direct functionalization of C(sp3)–H bonds under mild conditions. Over past decade, there have been remarkable advances in enantioselective bond via combined with conventional asymmetric catalysis. Herein, we summarize involving discuss two main pathways this emerging field: (a) SET-driven carbocation intermediates are followed by stereospecific nucleophile attacks; (b) photodriven alkyl radical further enantioselectively captured (i) chiral π-SOMOphile reagents, (ii) stereoselective transition-metal complexes, (iii) another distinct stereoscopic species. We aim key reaction design, catalyst development, mechanistic understanding, new insights into rapidly evolving area research.

Язык: Английский

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Photocatalysis Meets Confinement: An Emerging Opportunity for Photoinduced Organic Transformations

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(15)

Опубликована: Янв. 19, 2024

Abstract The self‐assembled metal‐organic cages (MOCs) have been evolved as a paradigm of enzyme‐mimic catalysts since they are able to synergize multifunctionalities inherent in metal and organic components constitute microenvironments characteristic enzymatic spatial confinement versatile host–guest interactions, thus facilitating unconventional transformations via unique driving‐forces such weak noncovalent binding electron/energy transfer. Recently, MOC‐based photoreactors emerged burgeoning platform supramolecular photocatalysis, displaying anomalous reactivities selectivities distinct from bulk solution. This perspective recaps two decades journey the photoinduced radical reactions by using photoactive (PMOCs) artificial reactors, outlining how cage‐confined photocatalysis was stoichiometric photoreactions photocatalytic turnover, high‐energy UV‐irradiation sustainable visible‐light photoactivation, simple multi‐level chemo‐ stereoselectivities. We will focus on PMOCs that merge structural functional biomimicry into single‐cage behave multi‐role photoreactors, emphasizing their potentials tackling current challenges through single‐electron transfer (SET) or energy (EnT) pathways simple, green while feasible manner.

Язык: Английский

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Quasi-Homogeneous Photocatalysis in Ultrastiff Microporous Polymer Aerogels

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15479 - 15487

Опубликована: Май 23, 2024

The development of efficient and low-cost catalysts is essential for photocatalysis; however, the intrinsically low photocatalytic efficiency as well difficulty in using recycling photocatalysts powder morphology greatly limit their practical performance. Herein, we describe quasi-homogeneous photocatalysis to overcome these two limitations by constructing ultrastiff, hierarchically porous, photoactive aerogels conjugated microporous polymers (CMPs). CMP exhibit density but high stiffness beyond 105 m2 s–2, outperforming most low-density materials. Extraordinary ensures use robust scaffolds scaled without damage at macroscopic level. A challenging desirable reaction direct deaminative borylation demonstrated aerogel-based with gram-scale productivity record-high under ambient conditions. Combined terahertz transient absorption spectroscopic studies unveil generation high-mobility free carriers long-lived excitonic species aerogels, underlying observed superior catalytic

Язык: Английский

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Advances in heterocycle synthesis through photochemical carbene transfer reactions

Chemical Communications, Год журнала: 2024, Номер 60(16), С. 2125 - 2136

Опубликована: Янв. 1, 2024

In this feature article, we focus on the photochemical strategy for construction of heterocyclic skeletons, specifically highlighting methods that employ visible light-promoted carbene transfer reactions.

Язык: Английский

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