Rhodium(II)-Catalyzed Allylic 1,3-Diamination DOI

Beiqi Yang,

Xinyu Liu, Aiwen Yu

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(21), P. 13411 - 13417

Published: Oct. 18, 2022

The intermolecular 1,3-diamination reaction of readily available alkenes with N-fluorobis(benzenesulfonamides) catalyzed by rhodium(II) is reported herein. isomers the terminal and internal alkenes, even mixtures, all provided same allylic 1,3-diamine products under mild conditions. resulting diaminated can be derived to functionalized diamines further generate triamines. Mechanistic studies revealed that compounds a variety chemical transformations during reactions based on their single-electron redox catalytic cycle, specifically radical polarity crossover in direct activation C–H bonds followed cross-coupling alkenes. These results show potential amination addition well-known rhodium nitrenoids.

Language: Английский

Use of Strain-Release for the Diastereoselective Construction of Quaternary Carbon Centers DOI

Tobias Pinkert,

Mowpriya Das, Malte L. Schrader

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(20), P. 7648 - 7654

Published: May 11, 2021

Herein, we describe the formation of quaternary carbon centers with excellent diastereoselectivity via a strain-release protocol. An organometallic species is generated by Cp*Rh(III)-catalyzed C–H activation, which then coupled strained bicyclobutanes (BCBs) and prochiral electrophile in three-component reaction. This work illustrates rare example BCBs transition metal catalysis demonstrates their broad potential to access novel reaction pathways. The method developed exhibits ample functional group tolerance, products can be further transformed into valuable α-quaternary β-lactones. Preliminary mechanistic investigations suggest twofold C–C bond cleavage sequence involving σ-bond insertion an ensuing β-carbon elimination event.

Language: Английский

Citations

53
Rhodium-Catalyzed Regio-, Diastereo-, and Enantioselective Three-Component Carboamination of Dienes via C–H Activation DOI

Ruijie Mi,

Xuepeng Zhang, Jinlei Wang

et al.

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(11), P. 6692 - 6697

Published: May 24, 2021

Reported herein is the rhodium-catalyzed enantioselective three-component coupling of arene, diene, and dioxazolone that occurs via C–H activation en route to allyl intermediate. This carboamination reaction affords chiral allylic amines in 1,2-selectivity, E-selectivity, enantioselectivity, with electrophilic amination π-allyl species being both regio- enantio-determining.

Language: Английский

Citations

46
Fun With Unusual Functional Groups: Sulfamates, Phosphoramidates, and Di‐tert‐butyl Silanols DOI
Shyam Sathyamoorthi

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(9)

Published: Jan. 16, 2024

Compared to ubiquitous functional groups such as alcohols, carboxylic acids, amines, and amides, which serve central "actors" in most organic reactions, sulfamates, phosphoramidates, di-

Language: Английский

Citations

6
Hydrogen-Evolution Allylic C(sp3)–H Alkylation with Protic C(sp3)–H Bonds via Triplet Synergistic Brønsted Base/Cobalt/Photoredox Catalysis DOI

Meng-Yuan Dong,

Chun-Yu Han,

Dong‐Sheng Li

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(15), P. 9533 - 9539

Published: July 21, 2022

Transition-metal-catalyzed allylic C(sp3)–H alkylation with carbon-center nucleophiles is a straightforward approach to C(sp3)–C(sp3) bond formation, which has found widespread application in organic synthesis. However, stoichiometric oxidants are typically required realize the transformation. Herein, by triplet synergistic merger of Brønsted base/cobalt/photoredox catalysis, mild protocol for hydrogen-evolution protic feedstocks was developed an oxidant-free manner. This operationally simple method enables direct wide range branched α-olefins diverse feedstocks. The synthetic robustness this strategy further demonstrated late-stage functionalization complex molecules and synthesis natural product dihydropallescensin D.

Language: Английский

Citations

27
Redox-Neutral Ni-Catalyzed sp3 C–H Alkylation of α-Olefins with Unactivated Alkyl Bromides DOI
Mikkel B. Buendia,

Bradley Higginson,

Søren Kegnæs

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(7), P. 3815 - 3820

Published: March 14, 2022

A light-induced redox-neutral Ni-catalyzed sp3 C–H alkylation of unactivated alkenes with alkyl bromides possessing β-hydrogens is described herein. The method distinguished by its simplicity, wide scope, and exquisite regio- chemoselectivity profile, thus offering an entry point to forge sp3–sp3 architectures.

Language: Английский

Citations

26
Rhodium-Catalyzed Allylic C–H Functionalization of Unactivated Alkenes with α-Diazocarbonyl Compounds DOI

Pinki Sihag,

Trisha Chakraborty,

Masilamani Jeganmohan

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(8), P. 1257 - 1262

Published: Feb. 16, 2023

A redox-neutral mild methodology for the allylic C–H alkylation of unactivated alkenes with diazo compounds is demonstrated. The developed protocol able to bypass possibility cyclopropanation an alkene upon its reaction acceptor–acceptor compounds. highly accomplished due compatibility various functionalized different sensitive functional groups. rhodacycle π-allyl intermediate has been synthesized and proved be active intermediate. Additional mechanistic investigations aided elucidation plausible mechanism.

Language: Английский

Citations

12
Electrochemical Allylic C(sp3)–H Isothiocyanation via [3,3]-Sigmatropic Rearrangement DOI

Xuezhuang Gao,

Hui He,

Kaili Miao

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(21), P. 4554 - 4559

Published: May 20, 2024

The direct allylic C(sp3)–H functionalization provides a straightforward protocol for the synthesis of valuable molecules. We report herein first chemo- and site-selective method isothiocyanation various internal alkenes under mild electrochemical conditions. This exhibits broad functional group tolerance excellent selectivity can be applied late-stage bioactive Combined experimental computational studies indicate that reaction proceeds via an unexpected [3,3]-sigmatropic rearrangement.

Language: Английский

Citations

4
Electrosynthesis of 1,4-diene derivatives bearing cyclopentene skeleton DOI Creative Commons

Yaqi Qiao,

Xiaoqing Fan,

Chengcheng Yuan

et al.

iScience, Journal Year: 2025, Volume and Issue: 28(3), P. 111976 - 111976

Published: Feb. 10, 2025

1,n-Dual Π systems including 1,4-diene derivatives have been widely used as the elegant radical receptors to promote cascade additions give highly functionalized polycyclic scaffolds. However, tedious and complicated preparation of former deters broad utilization compromises practical value. Herein, a straightforward was developed from easily accessible alkynes γ,δ-unsaturated carboxylic acids via electrochemical oxidation cyclization Hofmann elimination. This transformation features with good excellent yields, functional group compatibility, selectivity without any Zaitsev elimination product detected.

Language: Английский

Citations

0
Mechanistic Insights into Copper-Catalyzed Asymmetric Cyanation of Allylic C–H Bonds DOI
Jiayuan Li, Tilong Yang, Pinhong Chen

et al.

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

Published: April 20, 2025

Direct C-H bond functionalization has emerged as one of the most powerful and practical strategies for modification drug molecules. We have recently disclosed a Cu/NFAS (NFAS = N-fluoroalkyl sufonamide) catalytic system that exhibits high site-, regio-, enantioselectivity direct cyanation allylic bonds. Here, we present mechanistic investigation this catalyst system, including elucidation side reactions involved in transformation. This work focuses on an in-depth analysis cycle based kinetic studies by NMR spectroscopy characterization speciation EPR UV-vis spectroscopy. These indicate fraction NFAS is sacrificed to Cu(II)-bounded N-centered radical (Cu(II)-NCR) species generation silylated sulfonamides (CN)2. The data also show great dependence reaction yield selectivity (hydrogen atom abstraction or HAA over reactions) structure Cu(II)-NCR species. Kinetic DFT calculations further reveal oxidation CuCN NFAS, process, Cu(II)-NCRs with TMSCN comparable energy barriers, which collectively determine rate overall reaction.

Language: Английский

Citations

0
Acceleration Mechanisms of C–H Bond Functionalization Catalyzed by Electron-Deficient CpRh(III) Complexes DOI
Yuki Nagashima,

Shiho Ishigaki,

Jin Tanaka

et al.

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(21), P. 13591 - 13602

Published: Oct. 26, 2021

A rhodium(III) complex bearing a 1,3-bis(ethoxycarbonyl)-substituted or an unsubstituted cyclopentadienyl ligand (CpE Cp) significantly accelerates variety of oxidative C–H bond functionalization reactions. However, the driving force acceleration compared with conventionally used Cp*Rh(III) has not been elucidated. Herein, we performed density functional theory (DFT) calculations rhodium(III)-catalyzed olefination and annulation reactions using Cp*, Cp, CpE ligands, which revealed that CpERh(III) stabilizes transition states only activation step but also rate-determining reductive elimination insertion steps by strong orbital interactions. For sterically demanding substrates, less hindered CpRh(III) can stabilize more than complex. Moreover, whole reaction pathways were calculated to elucidate mechanism selectivity [4 + 2] [2 2 under cationic neutral conditions, respectively.

Language: Английский

Citations

25