Palladium-Catalyzed Allylation of Endocyclic 1-Azaallyl Anions DOI
Xiaoyu Yang, Biao Zhang,

Junhao Ruan

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(12), P. 8896 - 8905

Published: June 10, 2024

Endocyclic 1-azaallyl anions engage allyl acetates in a palladium-catalyzed allylation followed by reduction to give unprotected 2-(hetero)aryl-3-allylpiperidines and 2-allyl-3-arylmorpholines, products not easily accessible other means. The group is then readily transformed into variety of functional groups. Preliminary studies on the asymmetric variant reaction using an enantiomerically pure BI-DIME-type ligand provide product with moderate enantioselectivity. Computational suggest that energy barriers inner-sphere reductive elimination outer-sphere nucleophilic substitution are almost same, which makes both them possible pathways. In addition, mechanism displays enantiodiscriminating C–C bond forming step, while much less selective, combined

Language: Английский

TEMPO Mediated Cyclopropanols Ring Opening C−N Cross‐Coupling with Nitrogen Nucleophiles DOI
Jun‐Long Zhan, Lin Zhu, Wei Ren

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(10), P. 1678 - 1684

Published: April 28, 2023

Abstract A feasible and umpolung strategy for the synthesis of structurally diverse β ‐amino ketones has been achieved through TEMPO mediated C−N coupling cyclopropanols with nitrogen nucleophiles. Mechanism studies indicated that in situ generated enones derived from are key intermediates play multiple roles, including radical initiator, trapping reagent, a porter ‐hydrogen an base. This protocol features broad substrate scope, good scalability to excellent yields provides alternative complementary approach important ketone scaffolds under metal additive‐free conditions. magnified image

Language: Английский

Citations

11
Nickel-Catalyzed Asymmetric Allylic Alkylation of β-Dicarbonyl Compounds via C–C Bond Activation of 2-Allylated Cyclic 1,3-Diketones DOI
Kosuke Higashida,

Valentin Smaïl,

Haruki Nagae

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(3), P. 2156 - 2161

Published: Jan. 25, 2023

The asymmetric allylic alkylation (AAA) reaction using less reactive, stable sources is challenging. We achieved a nickel(0)-catalyzed AAA of β-dicarbonyl compounds under ambient conditions through unstrained C–C bond activation 2-allylated 2-methylcyclohexane-1,3-dione derivatives to afford the corresponding quaternary chiral in high yield with enantioselectivity. proceeded almost irreversibly due low solubility side-product, 2-methylcyclohexane-1,3-dione. Control experiments and DFT calculations allowed for elucidating mechanism Ni(0)-(S)-tol-MeO-BIPHEP catalyst system; turnover limiting step formation, reverse requires 7.6 kcal mol–1 higher energy than forward reaction.

Language: Английский

Citations

10
Chemo- and Regioselectivity in Allenamide-Homoenolate Coupling DOI

Raju Teegala,

B. Purna Chandra Rao,

Kadiyala Sagar

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

We report herein a chelation assisted, ring-strain-driven homoenolate interception with allenamides, proceeding through complementary reactivity pattern─noncycloaddition and central C of C-pronucleophiles─distinct from previous studies. The developed atom-economical method provides access to carbonyl-tagged enamides high chemo- regioselectivity, offering broad scope significant synthetic value, as demonstrated by further diversification. origin the selectivity is clarified experimental mechanistic investigations, revealing detailed reaction pathway carbopalladation event.

Language: Английский

Citations

0
Iron Mediated Oxidative Ring Opening‐Homocoupling of Cyclopropanols: Facile Access to 1,6‐Diketones DOI
Ravi A. Shinde, Sachin R. Shirsath,

M. Muthukrishnan

et al.

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(18)

Published: May 1, 2025

Abstract We have developed a new approach for the synthesis of 1,6‐diketones via iron‐catalyzed ring opening cyclopropanol with nontoxic, inexpensive iron catalyst under open‐air conditions. This method eliminates need additives and employs tert ‐butanol as an eco‐friendly solvent. methodology allows rapid access to variety symmetrical mild Preliminary mechanistic studies revealed involvement radical pathways.

Language: Английский

Citations

0
ProPhenol Derived Ligands to Simultaneously Coordinate a Main‐Group Metal and a Transition Metal: Application to a Zn−Cu Catalyzed Reaction DOI
Barry M. Trost, Guoting Zhang, Minghao Xu

et al.

Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 28(9)

Published: Dec. 13, 2021

A new bifunctional ligand bearing chiral N-heterocyclic carbene (NHC) and prolinol moieties is presented. Utilizing the designed ligand, an in situ formed Cu/Zn hetero-bimetallic complex unlocks asymmetric allylic alkylation reactions of allyl phosphates with zinc keto-homoenolates, leading to formation various γ-vinyl ketones good regio- enantio-selectivity. DF sT calculation supports that chelation catalyst promotes SN 2' addition ligand-substrate steric interactions account for stereoselective outcome.

Language: Английский

Citations

20
Asymmetric β-arylation of cyclopropanols enabled by photoredox and nickel dual catalysis DOI Creative Commons
Jianhua Wang, Xiaoxun Li

Chemical Science, Journal Year: 2022, Volume and Issue: 13(10), P. 3020 - 3026

Published: Jan. 1, 2022

An asymmetric β-arylation of cyclopropanols with aryl bromides was enabled by enantioselective photoredox and nickel dual catalysis.

Language: Английский

Citations

13
Zinc‐Mediated Diastereoselective Annulation of Cyclopropanols with Alkylidenemalononitriles via Enolized Homoenolate DOI

Kento Tsukiji,

Takeru Hayakawa,

Kazuya Kanemoto

et al.

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(5)

Published: April 13, 2023

Abstract A zinc‐mediated annulation reaction between cyclopropanols and alkylidenemalononitriles is reported. The promoted in the presence of Et 2 Zn 1,4‐diazabicyclo[2.2.2]octane (DABCO) DMSO at 80 °C, affording cyclopropane‐fused 6‐amino‐3,4‐dihydro‐2 H ‐pyran‐5‐carbonitrile derivatives moderate to good yields with high diastereoselectivity. proposed involve an enolized homoenolate as key reactive intermediate, which generated through ring opening zinc cyclopropoxide enolization resulting homoenolate. enolate moiety this species undergoes Michael addition alkylidenemalononitrile, followed by closure α‐functionalized intramolecular cyclization one cyano groups.

Language: Английский

Citations

7
Uracil-Cu(i) catalyst: allylation of cyclopropanols with Morita–Baylis–Hillman alcohols under water-tolerant conditions DOI Creative Commons
Jingwei Hou, Xiaohong Li,

Kaiyu Yan

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 15(3), P. 1143 - 1149

Published: Dec. 7, 2023

Inspired by the high affinity of copper with DNA and RNA, a uracil-copper catalytic system was developed to promote ring-opening allylation cyclopropanols allylic alcohols under water-tolerant conditions. A new C-OH bond-breaking model can well resolve trade-off between need for acidic activators C(allyl)-OH bond cleavage demand strong basic conditions generating homoenolates. Therefore, Morita-Baylis-Hillman alcohols, rather than their pre-activated versions, could be incorporated directly into dehydrative cross-coupling delivering water as only by-product. variety functionalized

Language: Английский

Citations

6
Copper-catalyzed yne-allylic substitutions: concept and recent developments DOI Creative Commons
Shuang Yang, Xinqiang Fang

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 2739 - 2775

Published: Oct. 31, 2024

The catalytic (asymmetric) allylation and propargylation have been established as powerful strategies allowing access to enantioenriched α-chiral alkenes alkynes. In this context, combining allylic propargylic substitutions offers new opportunities expand the scope of transition metal-catalyzed substitution reactions. Since its discovery in 2022, copper-catalyzed yne-allylic has undergone rapid development significant progress made using key copper vinyl allenylidene intermediates. This review summarizes developments illustrates influences salt, ligand, pattern substrate on regioselectivity stereoselectivity.

Language: Английский

Citations

2
Insights into the Mechanism of Enantioselective Copper‐Catalyzed Ring‐Opening Allylic Alkylation of Cyclopropanols DOI

Akito Kitabayashi,

Sho Mizushima,

Kosuke Higashida

et al.

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(11), P. 1855 - 1862

Published: April 18, 2022

Abstract Enantioselective copper‐catalyzed ring‐opening allylic alkylation of a cyclopropanol with an allyl phosphate was developed using phenol‐NHC chiral ligand. DFT calculations indicated that copper homoenolate is formed via Li−Cu bimetallic activation cyclopropoxide and syn ‐S N 2’ attack the Cu center to followed by facile C−C bond formation affords β‐allylated ketone. Noncovalent interaction analysis showed enantiocontrol achieved synergy electrostatic interactions among Cu, Li, O atoms, C−H⋅⋅⋅O interactions, C−H/π London dispersions. magnified image

Language: Английский

Citations

9