Visible-Light-Promoted Regioselective 1,3-Fluoroallylation of gem-Difluorocyclopropanes DOI
Haidong Liu,

Yi Li,

Dingxing Wang

et al.

Organic Letters, Journal Year: 2020, Volume and Issue: 22(21), P. 8681 - 8686

Published: Oct. 28, 2020

A strategically novel protocol for ring-opening functionalization of aryl gem-difluorocyclopropanes (F2CPs), which allows an expedient construction CF3-containing architectures via visible-light-promoted F-nucleophilic attack manifold, was disclosed. Single electron oxidation F2CPs ascribed as the critical step success this transformation by prompting attack, well ensuing C–C bond scission. The observed intriguing regioselectivity fluoroincorporation in reaction rationalized invoking cation-stabilization property gem-difluorine substituents and also thermodynamic gains acquired from forming CF3 functionality. By using cost-effective fluorination reagent readily available substrates, a broad collection structurally diversified α-allyl-β-trifluoromethyl ethylbenzene derivatives could be obtained generally good yields. Further mechanistic investigations proved engagement benzylic radical intermediate transformation.

Language: Английский

Versatile Cobalt-Catalyzed Enantioselective Entry to Boryl-Functionalized All-Carbon Quaternary Stereogenic Centers DOI
Chao Wang, Shaozhong Ge

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(34), P. 10687 - 10690

Published: Aug. 16, 2018

We report an asymmetric synthesis of chiral boryl-functionalized γ-lactams containing all-carbon quaternary stereocenters via a Co-catalyzed enantioselective hydroboration/cyclization amide-tethered 1,6-enynes. These enantio-enriched γ-lactam products can be readily converted to variety cyclic and acyclic other γ-lactams, pyrrolidin-2,3-diones, β-amino acid N-carboxyanhydrides, carboxylic amides.

Language: Английский

Citations

100
Photoredox‐Coupled F‐Nucleophilic Addition: Allylation of gem‐Difluoroalkenes DOI
Haidong Liu, Liang Ge,

Ding‐Xing Wang

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(12), P. 3918 - 3922

Published: Jan. 29, 2019

A novel strategy for the expedient construction of CF3 -embeded tertiary/quarternary carbon centers was developed by taking advantage photoredox catalysis. Thanks to a key step single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, provides an elegant example generation, as well functionalization, α-CF3 -substituted benzylic radical intermediates using cheap and available starting materials.

Language: Английский

Citations

99
Hydrogen‐Transfer‐Mediated α‐Functionalization of 1,8‐Naphthyridines by a Strategy Overcoming the Over‐Hydrogenation Barrier DOI
Xiuwen Chen, He Zhao,

Chunlian Chen

et al.

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(45), P. 14232 - 14236

Published: Sept. 19, 2017

A general catalytic hydrogen transfer-mediated α-functionalization of 1,8-naphthyridines is reported for the first time that benefits from a activation mode non-activated pyridyl cores. The α-site selectively couples with C8-site various tetrahydroquinolines (THQs) to afford novel α-functionalized tetrahydro 1,8-naphthyridines, class synthetically useful building blocks and potential candidates discovery therapeutic bio-active products. utilization THQs as inactive donors (HDs) appears be key strategy overcome over-hydrogenation barrier address chemoselectivity issue. developed chemistry features operational simplicity, readily available catalyst good functional group tolerance, offers significant basis further development new protocols directly transform or functionalize inert N-heterocycles.

Language: Английский

Citations

91
Nickel/N-Heterocyclic Carbene Complex-Catalyzed Enantioselective Redox-Neutral Coupling of Benzyl Alcohols and Alkynes to Allylic Alcohols DOI
Yuan Cai, Jiawen Zhang, Feng Li

et al.

ACS Catalysis, Journal Year: 2018, Volume and Issue: 9(1), P. 1 - 6

Published: Nov. 29, 2018

The nickel-catalyzed enantioselective redox-neutral coupling of alcohols and alkynes to access chiral allylic is reported. reaction proceeds via a hydrogen transfer process under ambient temperature, converting abundant feedstock with high stereoselectivities in one chemical step. Key the success this was development bulky N-heterocyclic carbene, (R,R,R,R)-SIPE, version SIPr, as ligand for nickel. Notably, we found that utilization P(OPh)3 secondary nickel crucial inhibit isomerization products.

Language: Английский

Citations

89
Engaging Aldehydes in CuH‐Catalyzed Reductive Coupling Reactions: Stereoselective Allylation with Unactivated 1,3‐Diene Pronucleophiles DOI
Chengxi Li, Kwangmin Shin, Richard Y. Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(47), P. 17074 - 17080

Published: Sept. 25, 2019

Abstract Recently, CuH‐catalyzed reductive coupling processes involving carbonyl compounds and imines have become attractive alternatives to traditional methods for stereoselective addition because of their ability use readily accessible stable olefins as surrogates organometallic nucleophiles. However, the inability aldehydes, which usually reduce too rapidly in presence copper hydride complexes be viable substrates, has been a major limitation. Shown here is that by exploiting relative concentration effects through kinetic control, this intrinsic reactivity can inverted 1,3‐dienes with aldehydes achieved. Using method, both aromatic aliphatic transformed into synthetically valuable homoallylic alcohols high levels diastereo‐ enantioselectivities, many useful functional groups. Furthermore, using combination theoretical (DFT) experimental methods, important mechanistic features reaction related stereo‐ chemoselectivities were uncovered.

Language: Английский

Citations

79
Catalytic Asymmetric Conjugate Protosilylation and Protoborylation of 2-Trifluoromethyl Enynes for Synthesis of Functionalized Allenes DOI
Chao Yang,

Zheng‐Li Liu,

Dong‐Ting Dai

et al.

Organic Letters, Journal Year: 2020, Volume and Issue: 22(4), P. 1360 - 1367

Published: Feb. 4, 2020

The Cu-catalyzed 1,4-protosilylation and protoborylation of trifluoromethyl-substituted conjugated enynes were developed to access functionalized homoallenylsilanes homoallenylboronates. This protocol also provides a general method synthesize optically active homoallenylboronates in moderate excellent yields with high enantiomeric excess by using new designed chiral bisoxazoline ligands. Simultaneously, the transformations explored useful building blocks.

Language: Английский

Citations

75
Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates DOI
Lei Wang, Lifan Wang, Mingxia Li

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(32), P. 12755 - 12765

Published: Aug. 5, 2021

Catalytic generation of ambiphilic π-allyl–metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction allyl groups to molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, protocol stereoselective formation nucleophilic allyl–Co(II) followed by addition aldehydes is presented. The reaction features diastereo- enantioconvergent conversion easily accessible allylic alcohol derivatives diversified enantioenriched homoallylic alcohols with remarkably broad scope that can be introduced. Mechanistic studies indicated radical intermediates were involved this process. These new discoveries establish strategy development through capture radicals chiral Co complexes, pushing forward the frontier catalysis.

Language: Английский

Citations

68
Allenes and Dienes as Chiral Allylmetal Pronucleophiles in Catalytic Enantioselective C=X Addition: Historical Perspective and State‐of‐The‐Art Survey DOI
Ming Xiang, Dana E. Pfaffinger, Michael J. Krische

et al.

Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 27(52), P. 13107 - 13116

Published: June 29, 2021

Abstract The use of allenes and 1,3‐dienes as chiral allylmetal pronucleophiles in intermolecular catalytic enantioselective reductive additions to aldehydes, ketones, imines, carbon dioxide other C=X electrophiles is exhaustively catalogued together with redox‐neutral hydrogen auto‐transfer processes. Coverage limited processes that result both C−H C−C bond formation. alkynes latent multicomponent allylations involving dienes not covered. As illustrated this review, the ability serve tractable non‐metallic has evoked many useful transformations have no counterpart traditional chemistry.

Language: Английский

Citations

67
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
Research progress in electrochemical/photochemical utilization of methanol as a C1 source DOI
Haitao Tang, Yong-Zhou Pan, Ying‐Ming Pan

et al.

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(21), P. 8313 - 8327

Published: Jan. 1, 2023

This review highlights the recent advances in various electrochemical and photochemical reactions using methanol as a sustainable C1 source.

Language: Английский

Citations

39