Green Chemistry, Год журнала: 2023, Номер 25(18), С. 7335 - 7343
Опубликована: Янв. 1, 2023
Reported here is the radical sequential (3 + 2) annulation of 1,6-enynes under concerted catalysis sulfinate and PC. Importantly, CO 2 as a green additive facilitates unusual 1,4-elimination via proton transfer to provide desulfonylated products.
Язык: Английский
Nature Communications, Год журнала: 2025, Номер 16(1)
Опубликована: Фев. 4, 2025
Asymmetric multicomponent reactions that aim to control multiple chiral centers with high selectivity in a single step remain an on-gonging challenge. The realm of enantioselective radical-polar crossover transformation achieved through C-H Functionalization has yet be fully explored. Herein, we present successful description photoredox/Cr-catalyzed three-component (hetero)arylalkylation 1,3-dienes functionalization. A diverse array homoallylic alcohols could obtained good excellent yields, accompanied by outstanding enantioselectivity. asymmetric build two simultaneously and demonstrates broad substrate tolerance, accommodating various drug-derived aldehydes, (hetero)aromatics, 1,3-diene derivatives. Preliminary mechanistic studies indicate the involvement radical intermediate, allylic chromium species reacting aliphatic aromatic aldehydes Zimmerman–Traxler transition states enabled dual photoredox catalysis. ongoing Here, authors photoredox- chromium-catalyzed
Язык: Английский
Процитировано
3
Nature Communications, Год журнала: 2022, Номер 13(1)
Опубликована: Авг. 26, 2022
Abstract The merger of photoredox and transition-metal catalysis has evolved as a robust platform in organic synthesis over the past decade. stereoselective 1,4-functionalization 1,3-enynes, prevalent synthon synthetic chemistry, could afford valuable chiral allene derivatives. However, tremendous efforts have been focused on ionic reaction pathway. radical-involved asymmetric 1,3-enynes remains prominent challenge. Herein, we describe three-component 1,4-dialkylation via dual chromium to provide allenols. This method features readily available starting materials, broad substrate scope, good functional group compatibility, high regioselectivity, simultaneous control axial central chiralities. Mechanistic studies suggest that this proceeds through redox-neutral
Язык: Английский
Процитировано
70
Journal of the American Chemical Society, Год журнала: 2022, Номер 144(48), С. 22140 - 22149
Опубликована: Ноя. 22, 2022
Photocatalysis opens up a new window for carbonyl chemistry. Despite multitude of photochemical reactions compounds, visible light-induced catalytic asymmetric transformations remain elusive and pose formidable challenge. Accordingly, the development simple, efficient, economic systems is ideal pursuit chemists. Herein, we report an enantioselective radical photoaddition to ketones through Lewis acid-enabled photoredox catalysis wherein in situ formed chiral N,N'-dioxide/Sc(III)-ketone complex serves as temporary photocatalyst trigger single-electron transfer oxidation silanes generation nucleophilic species, including primary, secondary, tertiary alkyl radicals, giving various enantioenriched aza-heterocycle-based alcohols good excellent yields enantioselectivities. The results electron paramagnetic resonance (EPR) high-resolution mass spectrum (HRMS) measurements provided favorable evidence stereocontrolled addition process involved this reaction.
Язык: Английский
Процитировано
53
Journal of the American Chemical Society, Год журнала: 2024, Номер 146(8), С. 5316 - 5323
Опубликована: Фев. 16, 2024
Efficient synthesis of enantioenriched amines is great importance due to their significant synthetic and biological applications. Photoredox-mediated asymmetric α-amino C(sp3)–H functionalization offers an atom-economical sustainable approach access chiral amines. However, the development analogous reactions in its early stages, generally affording with a single stereocenter. Herein, we present novel synergistic triple-catalysis for α-C–H addition readily available N-sulfonyl aldehydes under mild conditions. This method allows efficient diverse array valuable β-amino alcohols bearing vicinal stereocenters. Unlike previous reports, our protocol employs radical using earth-abundant Cr catalysis. Quinuclidine plays dual role by facilitating highly selective hydrogen-atom transfer generate radicals promoting dissociation Cr–O bond, which crucial overall catalytic cycle as evidenced control, NMR, DFT experiments. Preliminary mechanistic studies, including trapping, nonlinear effect, Stern–Volmer plot, kinetic isotope Hammett offer insights into reaction pathway.
Язык: Английский
Процитировано
17
Chem, Год журнала: 2024, Номер 10(3), С. 998 - 1014
Опубликована: Янв. 24, 2024
Язык: Английский
Процитировано
16
Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(37)
Опубликована: Июнь 21, 2022
The Brook rearrangement has already become established as one of the most important molecular rearrangements in synthetic chemistry and been applied generation complexes, drug discovery, material science, natural products synthesis. Compared to widely known ionic mechanism, radical is less explored because difficulty generating alkoxyl species. This Minireview summarizes early developments general concept highlights recent advances photocatalytic reactions transition-metal-catalyzed cross-coupling involving rearrangements. We hope this survey will inspire further emerging area.
Язык: Английский
Процитировано
37
ACS Central Science, Год журнала: 2023, Номер 9(4), С. 756 - 762
Опубликована: Март 27, 2023
Direct functionalization of inert C-H bonds is one the most attractive yet challenging strategies for constructing molecules in organic chemistry. Herein, we disclose an unprecedented and Earth abundant Cu/Cr catalytic system which unreactive alkyl are transformed into nucleophilic alkyl-Cr(III) species at room temperature, enabling carbonyl addition reactions with strong bonds. Various aryl alcohols furnished under mild reaction conditions even on a gram scale. Moreover, this new radical-to-polar crossover approach further applied to 1,1-difunctionalization aldehydes alkanes different nucleophiles. Mechanistic investigations reveal that aldehyde not only acts as reactant but also serves photosensitizer recycle Cu Cr catalysts.
Язык: Английский
Процитировано
22
Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(2)
Опубликована: Ноя. 10, 2023
Abstract We report a mild, catalytic method for the intermolecular reductive coupling of feedstock dienes and styrenes with ketones. Our conditions allow concomitant formation cobalt hydride species single‐electron reduction Subsequent selective hydrogen‐atom transfer from generates an allylic radical which can selectively couple persistent radical‐anion ketone. This radical‐radical negates unfavourable steric interactions ionic pathways avoids unstable alkoxy previous olefin‐carbonyl couplings, were limited, as result, to aldehydes. Applications this novel straightforward approach include efficient synthesis drug molecules, key intermediates in site‐selective late‐stage functionalisation.
Язык: Английский
Процитировано
21
Nature Communications, Год журнала: 2023, Номер 14(1)
Опубликована: Сен. 2, 2023
Six-membered N-containing heterocycles, such as 2-piperidinone derivatives, with diverse substitution patterns are widespread in natural products, drug molecules and serve key precursors for piperidines. Thus, the development of stereoselective synthesis multi-substituted 2-piperidinones attractive. However, existing methods heavily rely on modification pre-synthesized backbones which require tedious multi-step procedure suffer from limited patterns. Herein, an organophotocatalysed [1 + 2 3] strategy was developed to enable one-step access substituted easily available inorganic ammonium salts, alkenes, unsaturated carbonyl compounds. This mild protocol exhibits exclusive chemoselectivity over two tolerating both terminal internal alkenes a wide range functional groups.
Язык: Английский
Процитировано
19
Organic Letters, Год журнала: 2024, Номер 26(8), С. 1550 - 1555
Опубликована: Фев. 16, 2024
We report a three-component Nozaki–Hiyama–Kishi type reaction of 1,3-dioxolane, 1,3-butadienes, and aldehydes to access masked aldehyde-incorporated homoallylic alcohols, facilitated by photo-hydrogen atom transfer (HAT)/chromium dual catalysis. The diaryl ketone serves roles both in the HAT process facilitating turnover chromium catalyst. A range functional groups are tolerated owing mild conditions. Both aromatic aliphatic suitable substrates for coupling with several 1,3-butadienes 1,3-dioxolane.
Язык: Английский
Процитировано
8