Acetate Assistance in Regioselective Hydroamination of Allenamides: A Combined Experimental and Density Functional Theory Study DOI
Tapas R. Pradhan, Abdikani Omar Farah,

Kadiyala Sagar

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(9), P. 5927 - 5940

Published: April 23, 2024

A key factor in the development of selective nucleophilic addition to allenamides is controlling reactivity electrophilic intermediates, which generally achieved using an activator via conjugated iminium intermediates. In this combined experimental and computational study, we show that a general highly chemoselective hydroamination can be accomplished combination 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) NaOAc. Experimental mechanistic studies revealed HFIP mediates proton transfer activate allenamide, while acetate additive significantly contributes N-selective interception. This strategy enables without use metals. We demonstrated various functionalized 1,3-diamines could readily synthesized diversified into value-added structural motifs. Detailed investigations density functional theory role NaOAc formation reactive ultimately governed 1,3-diamine products. Critically, calculations potential energy surface around proton-transfer transition state two different intermediates were formed when was added.

Language: Английский

Transition metals-catalyzed amination of biomass feedstocks for sustainable construction of N-heterocycles DOI
Qiong Yan, Xu Wu, Hao Jiang

et al.

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 502, P. 215622 - 215622

Published: Dec. 26, 2023

Language: Английский

Citations

74
Progression of Hydroamination Catalyzed by Late Transition-Metal Complexes from Activated to Unactivated Alkenes DOI
Senjie Ma, John F. Hartwig

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(12), P. 1565 - 1577

Published: June 5, 2023

ConspectusCatalytic intermolecular hydroamination of alkenes is an atom- and step-economical method for the synthesis amines, which have important applications as pharmaceuticals, agrochemicals, catalysts, materials. However, hydroaminations in high yield with selectivity are challenging to achieve because these reactions often lack a thermodynamic driving force accompanied by side reactions, such alkene isomerization, telomerization, oxidative amination. Consequently, early examples were generally limited additions N-H bonds conjugated or strained alkenes, catalytic unactivated late transition metals has only been disclosed recently. Many classes including metals, rare-earth acids, photocatalysts, reported hydroamination. Among them, transition-metal complexes possess several advantages, their relative ease handling compatibility substrates containing polar sensitive functional groups.This Account describes progression our laboratory catalyzed from initial activated more recent alkenes. Our developments include Markovnikov anti-Markovnikov vinylarenes palladium, rhodium, ruthenium, dienes trienes nickel hydroanimation bicyclic neutral iridium, terminal internal cationic iridium ruthenium. Enantioselective form enantioenriched, chiral amines also developed.Mechanistic studies elucidated elementary steps turnover-limiting reactions. The nickel, ruthenium occurs nucleophilic attack amine on coordinated benzyl, allyl, alkene, arene ligand. On other hand, unconjugated migratory insertion into metal-nitrogen bond. In addition, pathways formation products, isomeric enamines, identified during studies. During enantioselective hydroamination, reversibility shown erode enantiopurity products. Based mechanistic understandings, new generations catalysts that promote higher rates, chemoselectivity, enantioselectivity developed. We hope discoveries insights will facilitate further development selective, practical, efficient

Language: Английский

Citations

47
Catalytic Asymmetric Hydroalkoxylation and Formal Hydration and Hydroaminoxylation of Conjugated Dienes DOI

Shao‐Qian Yang,

Aijun Han, Yang Liu

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3915 - 3925

Published: Feb. 10, 2023

The straightforward construction of stereogenic centers bearing unprotected functional groups, as in nature, has been a persistent pursuit synthetic chemistry. Abundant applications free enantioenriched allyl alcohol and hydroxylamine motifs have made the asymmetric hydration hydroaminoxylation conjugated dienes from water hydroxylamine, respectively, intriguing efficient routes that have, however, unachievable thus far. A fundamental challenge is failure to realize transition-metal-catalyzed enantioselective C–O bond constructions via hydrofunctionalization dienes. Here, we perform comprehensive study toward stereoselective formal by synthesizing set new P,N-ligands identifying an aryl-derived oxime surrogate for both hydroxylamine. Asymmetric hydroalkoxylation with also elucidated. Furthermore, versatile derivatizations following provide indirect but concise hydrophenoxylation, hydrofluoroalkoxylation, hydrocarboxylation unreported Finally, ligand-to-ligand hydrogen transfer process proposed based on results preliminary mechanistic experiments.

Language: Английский

Citations

44
Azolation of Benzylic C–H Bonds via Photoredox-Catalyzed Carbocation Generation DOI
Mrinmoy Das,

Leila Zamani,

Christopher Bratcher

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3861 - 3868

Published: Feb. 9, 2023

A visible-light photoredox-catalyzed method is reported that enables the coupling between benzylic C-H substrates and N-H azoles. Classically, medicinally relevant

Language: Английский

Citations

42
Cu-Catalyzed Asymmetric Dicarboxylation of 1,3-Dienes with CO2 DOI
Yong‐Yuan Gui, Xiao‐Wang Chen,

Xiao-Yan Mo

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(5), P. 2919 - 2927

Published: Jan. 26, 2024

Dicarboxylic acids and derivatives are important building blocks in organic synthesis, biochemistry, the polymer industry. Although catalytic dicarboxylation with CO2 represents a straightforward sustainable route to dicarboxylic acids, it is still highly challenging limited generation of achiral or racemic acids. To date, asymmetric give chiral has not been reported. Herein, we report first 1,3-dienes via Cu catalysis. This strategy provides an efficient environmentally benign high regio-, chemo-, enantioselectivities. The copper self-relay catalysis, that is, Cu-catalyzed boracarboxylation carboxylated allyl boronic ester intermediates subsequent carboxylation C–B bonds dicarboxylates, key success this dicarboxylation. Moreover, protocol exhibits broad substrate scope, good functional group tolerance, easy product derivatizations, facile synthesis liquid crystalline polyester drug-like scaffolds.

Language: Английский

Citations

29
Palladium-Catalyzed Asymmetric Sequential Hydroamination of 1,3-Enynes: Enantioselective Syntheses of Chiral Imidazolidinones DOI
Qiu‐Yu Li, Xinxin Fang, Rui Pan

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(25), P. 11364 - 11376

Published: June 10, 2022

Pd-catalyzed sequential hydroamination of readily available 1,3-enynes is reported. The redox-neutral process provides an efficient route to synthesize a broad scope imidazolidinones, thiadiazolidines, and imidazolidines. Asymmetric generates series synthetically valuable, enantioenriched imidazolidinones. Mechanistic studies revealed that the transformation occurred via intermolecular enyne pathway give allene intermediate. Subsequent intramolecular intermediate proceeded under Curtin-Hammett principle provide imidazolidinone products.

Language: Английский

Citations

59
Enantioselective Hydroalkoxylation of 1,3-Dienes via Ni-Catalysis DOI Creative Commons
Qi Li, Zhen Wang, Vy M. Dong

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3909 - 3914

Published: Feb. 10, 2023

As an advance in hydrofunctionalization, we herein report that alcohols add to 1,3-dienes with high regio- and enantioselectivity. Using Ni-DuPhos, access enantioenriched allylic ethers. Through the choice of solvent-free conditions, control reversibility C–O bond formation. This work showcases a rare example methanol as reagent asymmetric synthesis.

Language: Английский

Citations

41
Stereodivergent Construction of Csp3−Csp3Bonds Bearing Vicinal Stereocenters by Synergistic Palladium and Phase‐Transfer Catalysis DOI

Jingqiang Han,

Rixin Liu,

Zitong Lin

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(2)

Published: Nov. 16, 2022

Abstract Synergistic catalysis has emerged as one of the most powerful tools for stereodivergent formation Csp 3 −Csp bonds bearing vicinal stereocenters. Despite many successes that have been achieved in this field, coupling reactions involving stabilized nucleophiles remain challenging because competing single‐catalysis pathway. Herein, we report a synergistic palladium/phase‐transfer catalyst system enables diastereodivergent 1,3‐dienes with nucleophile oxindoles. Both syn and anti products, quaternary tertiary stereocenters, could be selectively produced good yields high enantio‐ diastereoselectivities. Non‐covalent activation via chiral ion pair biphasic is crucial success factor achieving diastereodivergence.

Language: Английский

Citations

40
Dual Photoredox and Copper Catalysis: Enantioselective 1,2-Amidocyanation of 1,3-Dienes DOI

Dan Forster,

Wei‐Si Guo,

Qian Wang

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(11), P. 7523 - 7528

Published: May 19, 2023

Dual photoredox–transition-metal catalysis has emerged as a powerful tool for the development of chemical transformations. However, its application in selective difunctionalization 1,3-dienes remains essentially unexploited. By synergistic action photoredox and copper catalysts, we report herein an enantioselective 1,2-amidocyanation 1,3-dienes. Visible-light irradiation chloroform solution conjugated dienes, N-Boc-amidopyridinium salts, TMSCN presence catalytic amount fac-Ir(ppy)3, Cu(OTf)2·xH2O, chiral Box ligand affords three-component adducts good to high yields with regio- enantioselectivities. A L*CuCN complex, fully characterized spectroscopically confirmed by X-ray crystallographic analysis, is able catalyze transformation, therefore supporting inner-sphere cyanide transfer pathway.

Language: Английский

Citations

24
Palladium(0) π-Lewis Base Catalysis: Concept and Development DOI
Zhichao Chen, Qin Ouyang, Wei Du

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 6422 - 6437

Published: March 1, 2024

The development of a new catalytic strategy plays vital role in modern organic chemistry since it permits bond formation an unprecedented and more efficient manner. Although the application preformed metal complexes as π-base-activated reagents have enabled diverse transformations elegantly, concept by directly utilizing transition metals π-Lewis base catalysts remain underdeveloped, especially field asymmetric catalysis. Here, we outline our perspective on discovery palladium(0) catalyst, which is capable increasing highest occupied molecular orbital (HOMO) energy both electron-neutral electron-deficient 1,3-dienes 1,3-enynes upon flexible η2-complexes formed situ resultant π-backdonation. Thus, fruitful carbon–carbon-forming reactions with electrophiles can be achieved enantioselectively vinylogous addition pattern, conceptually different from classical oxidative cyclization mechanism. Emphasis will given to mechanism elucidation, features, reaction design together further this emerging field.

Language: Английский

Citations

14