tert‐Butyl as a Functional Group: Non‐Directed Catalytic Hydroxylation of Sterically Congested Primary C−H Bonds DOI Creative Commons
Siu‐Chung Chan, Andrea Palone, Massimo Bietti

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(28)

Published: May 1, 2024

Abstract The tert ‐butyl group is a common aliphatic motif extensively employed to implement steric congestion and conformational rigidity in organic organometallic molecules. Because of the combination high bond dissociation energy (~100 kcal mol −1 ) limited accessibility, absence directing groups, neither radical nor approaches are effective for chemical modification C−H bonds. Herein we overcome these limits by employing highly electrophilic manganese catalyst, [Mn( CF3 bpeb)(OTf) 2 ], that operates strong hydrogen donor solvent nonafluoro‐ alcohol (NFTBA) catalytically activates peroxide generate powerful manganese‐oxo species effectively oxidizes Leveraging on interplay steric, electronic, medium torsional effects, site‐selective product chemoselective hydroxylation accomplished with broad reaction scope, delivering primary alcohols as largely dominant products preparative yields. Late‐stage at sites demonstrated 6 densely functionalized molecules pharmaceutical interest. This work uncovers novel disconnection approach, harnessing potential functional strategic synthetic planning complex molecular architectures.

Language: Английский

Ligand‐Controlled Stereoselective Synthesis of 2‐Deoxy‐β‐C‐glycosides by Cobalt Catalysis DOI

Bingxue Liu,

Deguang Liu, Xianle Rong

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(22)

Published: March 17, 2023

2-Deoxy-β-C-glycosides represent an important class of carbohydrates that are present in many bioactive molecules. However, owing to the lack substituents at C2 position, stereoselective synthesis 2-deoxy-β-C-glycosides is highly challenging. Herein, we report a ligand-controlled C-alkyl glycosylation reaction access 2-deoxy-β-C-alkyl glycosides from readily available glycals and alkyl halides. This method exhibits broad substrate scope excellent diastereoselectivity under very mild conditions. In addition, unprecedented stereodivergent 2-deoxy-C-ribofuranosides achieved using different chiral bisoxazoline ligands. Mechanistic studies suggest hydrometallation glycal with bisoxazoline-ligated Co-H species may be turnover-limiting stereodetermining step this transformation.

Language: Английский

Citations

35
C–H Bonds as Functional Groups: Simultaneous Generation of Multiple Stereocenters by Enantioselective Hydroxylation at Unactivated Tertiary C–H Bonds DOI Creative Commons
Andrea Palone, Guillem Casadevall, Sergi Ruiz‐Barragán

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(29), P. 15742 - 15753

Published: July 11, 2023

Enantioselective C–H oxidation is a standing chemical challenge foreseen as powerful tool to transform readily available organic molecules into precious oxygenated building blocks. Here, we describe catalytic enantioselective hydroxylation of tertiary bonds in cyclohexane scaffolds with H2O2, an evolved manganese catalyst that provides structural complementary the substrate similarly lock-and-key recognition operating enzymatic active sites. Theoretical calculations unveil enantioselectivity governed by precise fitting scaffold site, through network weak non-covalent interactions. Stereoretentive C(sp3)–H results single-step generation multiple stereogenic centers (up 4) can be orthogonally manipulated conventional methods providing rapid access, from single precursor variety chiral scaffolds.

Language: Английский

Citations

24
Aminodealkenylation: Ozonolysis and copper catalysis convert C(sp 3 )–C(sp 2 ) bonds to C(sp 3 )–N bonds DOI
Zhiqi He, Jose Antonio Moreno, Manisha Swain

et al.

Science, Journal Year: 2023, Volume and Issue: 381(6660), P. 877 - 886

Published: Aug. 24, 2023

Great efforts have been directed toward alkene π bond amination. In contrast, analogous functionalization of the adjacent C(sp

Language: Английский

Citations

24
(Z)-Selective Isomerization of 1,1-Disubstituted Alkenes by Scandium-Catalyzed Allylic C–H Activation DOI
Shao‐Jie Lou, Pan Wang, Xin Wen

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(39), P. 26766 - 26776

Published: Sept. 20, 2024

The isomerization of 1,1-disubstituted alkenes through 1,3-hydrogen shift is an atom-efficient route for synthesizing trisubstituted alkenes, which are important moieties in many natural products, pharmaceuticals, and organic materials. However, this reaction often encounters regio- stereoselectivity challenges, typically yielding

Language: Английский

Citations

8
Structural Design of Single‐Atom Catalysts for Enhancing Petrochemical Catalytic Reaction Process DOI
Min Li,

Guangxun Sun,

Zhidong Wang

et al.

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(25)

Published: March 18, 2024

Abstract Petroleum, as the “lifeblood” of industrial development, is important energy source and raw material. The selective transformation petroleum into high‐end chemicals great significance, but still exists enormous challenges. Single‐atom catalysts (SACs) with 100% atom utilization homogeneous active sites, promise a broad application in petrochemical processes. Herein, research systematically summarizes recent progress SACs catalytic reaction, proposes role structural design enhancing performance, elucidates reaction mechanisms conversion processes, reveals high activity origins at atomic scale. Finally, key challenges are summarized an outlook on design, identification appropriate artificial intelligence technology provided for achieving scale‐up process.

Language: Английский

Citations

7
Palladium-catalyzed enantioselective β-hydride elimination for the construction of remote stereocenters DOI Creative Commons
Shaozi Sun, Shengnan Sun, Weiwei Zi

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: March 5, 2025

The β-H elimination is a crucial elementary step in transition-metal catalysis, but controlling the stereochemistry of this process has been underdeveloped. limited works reported so far have only focused on creating axial chirality allenes, and no report able to build central using asymmetric elimination. In study, we Trost ligand-enabled enantioselective desymmetric reaction from π-allyl-Pd. This transformation provides rapid access cyclohexenes bearing C4-remoted stereocenter, total synthesis (-)-oleuropeic acid (-)-7-hydroxyterpineol demonstrated. Computational studies shown that rate-determining step, non-covalent interactions between amide moiety ligand benzene cyclohexane moieties substrate play key role stereocontrol during

Language: Английский

Citations

1
Regiodivergent Hydroamidation of Alkenes via Cobalt-Hydride Catalysis DOI

Bingxue Liu,

Qianqian Lü, Xiao Hu

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 10, 2025

Regiodivergent hydroamin(d)ation of alkenes presents a valuable strategy for the synthesis diverse amines or amides from common set starting materials, yet achieving controlled regioselectivity remains significant challenge. In this work, we present cobalt-catalyzed regiodivergent hydroamidation alkenes, enabling enantioselective ipso- and migratory heterocyclic alkenes. The ability to finely tune various reaction parameters allows seamless switch in regioselectivity. Notably, selectivity are governed by choice cobalt catalyst anions. Mechanistic studies reveal neutral Co-H species mediating ipso-hydroamidation cationic intermediate promoting hydroamidation. This protocol exhibits broad substrate scope, high functional group tolerance, provides an efficient pathway synthetizing structurally amides.

Language: Английский

Citations

1
Catalytic 1,3-Proton Transfer in Alkenes Enabled by Fe═NR Bond Cooperativity: A Strategy for pKa-Dictated Regioselective Transposition of C═C Double Bonds DOI
Yafei Gao, Xuelian Li, Jeremiah E. Stevens

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(22), P. 11978 - 11987

Published: May 25, 2023

Transition metal catalyzed alkene double bond transposition usually involves hydride intermediates. Despite significant advances in the design of catalysts that dictate product selectivity, control over substrate selectivity is less advanced and transition selectively transpose bonds substrates containing multiple 1-alkene functionalities are rare. Herein, we report three-coordinate high spin (S = 2) Fe(II) imido complex [Ph2B(tBuIm)2Fe═NDipp][K(18-C-6)THF2] (1-K(18-C-6)) catalyzes 1,3-proton transfer from to afford 2-alkene products. Mechanistic investigations involving kinetics, competition, isotope labeling studies, supported by experimentally calibrated DFT computations, strongly support an unusual nonhydridic mechanism for enabled cooperative action iron center basic ligand. As dictated pKa allylic protons, this catalyst enables regioselective C═C 1-alkenes. The state allows a wide scope functional groups be tolerated, including those typical poisons, such as amines, N-heterocycles, phosphines. These results demonstrate new strategy metal-catalyzed with predictable regioselectivity.

Language: Английский

Citations

14
Switching between Hydrogenation and Olefin Transposition Catalysis via Silencing NH Cooperativity in Mn(I) Pincer Complexes DOI Creative Commons
Wenjun Yang, Ivan Yu. Chernyshov, Manuela Weber

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(17), P. 10818 - 10825

Published: Aug. 19, 2022

While Mn-catalyzed (de)hydrogenation of carbonyl derivatives has been well established, the reactivity Mn hydrides with olefins remains very rare. Herein, we report a Mn(I) pincer complex that effectively promotes site-controlled transposition olefins. This is shown to emerge once N-H functionality within Mn/NH bifunctional suppressed by alkylation. detrimental for (de)hydrogenation, such masking cooperative allows highly efficient conversion wide range allylarenes higher-value 1-propenybenzenes in near-quantitative yield excellent stereoselectivities. The toward single positional isomerization was also retained long-chain alkenes, resulting regioselective formation 2-alkenes, which are less thermodynamically stable compared other possible products. detailed mechanistic analysis reaction between activated catalyst and points catalysis operating via metal-alkyl mechanism-one three conventional mechanisms previously unknown complexes.

Language: Английский

Citations

23
Catalytic asymmetric olefin isomerization: Facile access to chiral carbon-stereogenic olefinic compounds DOI Creative Commons

Xufang Liu,

Qiang Liu

Chem Catalysis, Journal Year: 2022, Volume and Issue: 2(11), P. 2852 - 2864

Published: Sept. 16, 2022

Language: Английский

Citations

22