C(sp3)–H cyanation by a formal copper(iii) cyanide complex DOI Creative Commons
Jamey K. Bower, Maxwell S. Reese, Ilia M. Mazin

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 14(5), P. 1301 - 1307

Published: Jan. 1, 2023

High-valent metal oxo complexes are prototypical intermediates for the activation and hydroxylation of alkyl C-H bonds. Substituting ligand with other functional groups offers opportunity additional functionalization beyond C-O bond formation. However, few species aside from have been reported to both activate functionalize We herein report first example an isolated copper(iii) cyanide complex (LCuIIICN) its cyanation reactivity. found that redox potential (Eox) substrates, instead dissociation energy, is a key determinant rate PCET, suggesting oxidative asynchronous CPET or ETPT mechanism. Among substrates same BDEs, those low potentials transfer H atoms up million-fold faster. Capitalizing on this mechanistic insight, we LCuIIICN highly selective amines, which predisposed stepwise H+/e-. Our study demonstrates effect PCET appealing tool controlling selectivity functionalization.

Language: Английский

Copper-catalyzed radical relay in C(sp3)–H functionalization DOI
Zuxiao Zhang, Pinhong Chen, Guosheng Liu

et al.

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(5), P. 1640 - 1658

Published: Jan. 1, 2022

Radical-involved transition metal (TM) catalysis has greatly enabled new reactivities in recent decades. Copper-catalyzed radical relay offers enormous potential C(sp3)-H functionalization which combines the unique regioselectivity of hydrogen atom transfer (HAT) and versatility copper-catalyzed cross-coupling. More importantly, significant progress been achieved asymmetric C-H through judicious ligand design. This tutorial review will highlight advances this rapidly growing area, we hope survey inspire future strategic developments for selective functionalization.

Language: Английский

Citations

226
Radical transformations for allene synthesis DOI Creative Commons
Yajun Li, Hongli Bao

Chemical Science, Journal Year: 2022, Volume and Issue: 13(29), P. 8491 - 8506

Published: Jan. 1, 2022

Allenes are valuable organic molecules that feature unique physical and chemical properties. They not only often found in natural products, but also act as versatile building blocks for the access of complex molecular targets, such pharmaceuticals, functional materials. Therefore, many remarkable elegant methodologies have been established synthesis allenes. Recently, more methods radical allenes developed, clearly emphasizing associated great synthetic values. In this perspective, we will discuss recent important advances

Language: Английский

Citations

79
Synergistic Pd/Cu-Catalyzed 1,5-Double Chiral Inductions DOI
Jiacheng Zhang, Yicong Luo, Zheng En

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(13), P. 9241 - 9251

Published: March 19, 2024

Much attention has been focused on the catalytic asymmetric creation of single chiral centers or two adjacent stereocenters. However, construction nonadjacent stereocenters is significant importance but challenging because lack remote induction models. Herein, based a C═C bond relay strategy, we report synergistic Pd/Cu-catalyzed 1,5-double model. All four stereoisomers target products bearing 1,5-nonadjacent involving both allenyl axial and central chirality could be obtained divergently by simply changing combination catalysts with different configurations. Control experiments DFT calculations reveal novel mechanism 1,5-oxidative addition, contra-thermodynamic η3-allyl palladium shift, conjugate nucleophilic substitution, which play crucial roles in control reactivity, regio-, enantio-, diastereoselectivity. It expected that this strategy may provide general protocol for synthesis structural motifs distant

Language: Английский

Citations

19
1,4-Alkylcarbonylation of 1,3-Enynes to Access Tetra-Substituted Allenyl Ketones via an NHC-Catalyzed Radical Relay DOI
Lei Chen, Lin Chen, Simiao Zhang

et al.

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(21), P. 13363 - 13373

Published: Oct. 19, 2021

Reactions involving allenyl ion intermediates have been widely applied in the synthesis of functionalized allenes, but reactions radicals less studied and limited successful examples realized mainly by transition metal catalysis. We herein demonstrate generation N-heterocyclic carbene (NHC) organocatalysis their applications three-component radical relay 1,4-alkylcarbonylation 1,3-enynes without participation. This strategy could accommodate a collection different alkyl precursors such as CF3I, halides, cycloketone oxime esters, aliphatic carboxylic acid derived redox-active enabling convenient pathway to access range synthetically challenging tetra-substituted ketones with high regioselectivity. The key success this protocol relied on Csp-C(O)sp2 radical–radical coupling NHC-bound ketyl radicals, constructing ketone motifs highly efficient reaction pathway.

Language: Английский

Citations

86
Copper-catalysed asymmetric radical cyanation DOI
Fei Wang, Pinhong Chen, Guosheng Liu

et al.

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(2), P. 107 - 116

Published: Jan. 31, 2022

Language: Английский

Citations

68
Site- and Enantioselective Manganese-Catalyzed Benzylic C–H Azidation of Indolines DOI
Min Cao, Hongliang Wang,

Yingang Ma

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(33), P. 15383 - 15390

Published: Aug. 11, 2022

A manganese-catalyzed highly site- and enantioselective benzylic C–H azidation of indolines has been described. The practical method is applicable for a tertiary bond with good functional group tolerance, allowing facile access to structurally diverse azide-containing in high efficiency excellent site-, chemo-, enantioselectivity. generality the was further demonstrated by secondary range indolines. allows straightforwardly enantioselectively install variety nitrogen-based groups bioactive molecules at C3 position indoline frameworks through post-azidation manipulations. Gram-scale synthesis also demonstrated, highlighting synthetic potential method. Mechanistic studies combined experiments computations elucidated reaction mechanism origins stereoselectivity.

Language: Английский

Citations

43
Copper-Catalyzed Asymmetric Functionalization of Vinyl Radicals for the Access to Vinylarene Atropisomers DOI
Liang Fu, Xin Chen, Wenzheng Fan

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(24), P. 13476 - 13483

Published: June 10, 2023

A novel asymmetric radical strategy for the straightforward synthesis of atropisomerically chiral vinyl arenes has been established herein, proceeding through copper-catalyzed atroposelective cyanation/azidation aryl-substituted radicals. Critical to success relay process is capture highly reactive radicals with L*Cu(II) cyanide or azide species. Moreover, these axially vinylarene products can be easily transformed into enriched amides and amines, enantiomerically benzyl nitriles via an axis-to-center chirality transfer process, pure organocatalyst chemo-, diastereo-, enantioselective (4 + 2) cyclization reaction.

Language: Английский

Citations

32
Photoexcited Palladium-Catalyzed Deracemization of Allenes DOI

Changhua Song,

Xiangbin Bai,

Bo Li

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(30), P. 21137 - 21146

Published: July 18, 2024

The different enantiomers of specific chiral molecules frequently exhibit disparate biological, physiological, or pharmacological properties. Therefore, the efficient synthesis single is particular importance not only to pharmaceutical sector but also other industrial sectors, such as agrochemical and fine chemical industries. Deracemization, a process during which racemic mixture converted into nonracemic product with 100% atom economy theoretical yield, most straightforward method access enantioenriched challenging task due decrease in entropy microscopic reversibility. Axially allenes bear distinctive structure two orthogonal cumulative π-systems are acknowledged synthetically versatile synthons organic synthesis. selective creation axially high optical purity under mild reaction conditions has always been very popular hot topic remains challenging. Herein, photoexcited palladium-catalyzed deracemization nonprefunctionalized disubstituted disclosed. This provides an economical strategy accommodate broad scope good enantioselectivities yields (53 examples, up 96% yield 95% ee). use suitable palladium complex visible light irradiation essential factor achieving this transformation. A metal-to-ligand charge transfer mechanism was proposed based on control experiments density functional theory calculations. Quantum mechanical studies implicate dual modes asymmetric induction behind our new protocol: (1) sterically controlled stereoselective binding one allene enantiomer ground-state (2) facile, noncovalent interaction-driven excited-state isomerization toward opposite enantiomer. success newly established photochemical should provide inspiration for expansion multisubstituted will open mode enantioselective catalysis.

Language: Английский

Citations

11
Palladium-Catalyzed Allylic Alkylation Reactions of Nucleophilic Allenones: Asymmetric Allylic Alkylation, Z/E Divergent Allylic Alkylation, and [5 + 2] Annulation DOI
Wang Wang, Yimin Hu, Kuan Li

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(13), P. 9940 - 9954

Published: June 19, 2024

Metal-catalyzed allenylic substitution reactions where allenes serve as electrophilic precursors have been recognized a rapid way for novel allene construction. On the contrary, chemistry in which act nucleophiles has far less investigated, especially powerful platform such metal-catalyzed allylic alkylation reactions. We herein describe two unprecedented palladium-catalyzed of an nucleophile. In first reaction, using vinyloxazolidinones allyl precursor, asymmetric allylation trisubstituted allenones worked well to prepare array axially chiral tetrasubstituted allenes. Mechanistic studies and density functional theory (DFT) calculations indicated that weak hydrogen-bonding interaction between acidic C(sp2)–H allenone nitrogen anion π-azaallyl-Pd species is key success stereocontrol. This reaction revealed intriguing reactivity nucleophilic time. second with use allenylethylene carbonates π-oxyallyl-Pd precursors, presented unique under different conditions provide divergent synthetic access (E)- (Z)-allenyl diene products. Interestingly, subsequent sequential intramolecular cyclization/isomerization (Z)-product delivered dihydrooxepine derivatives [5 + 2] annulation

Language: Английский

Citations

10
Recent advances in the metal-catalyzed asymmetric synthesis of chiral allenes DOI
Wei Xiao, Jie Wu

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(18), P. 5053 - 5073

Published: Jan. 1, 2022

Recent advances in the metal-catalyzed asymmetric synthesis of chiral allenes are summarized. This review is categorized based on starting material, including alkynes, racemic allenes, and conjugated dienes.

Language: Английский

Citations

35