Visible Light‐Induced Umpolung Synthesis of 3,3‐Disubstituted Oxindoles via the Substrate‐Photosensitive Strategy DOI
H. J. Yang, Ting-Ting Wang,

Benhui Sui

и другие.

Chinese Journal of Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 25, 2024

Comprehensive Summary 3,3‐Disubstituted oxindoles, forming the core of extensive bioactive natural products and drugs, attract tremendous efforts to develop efficient methods for their preparation. Here, a photocatalyst‐free approach synthesis 3,3‐disubstituted oxindoles via substrate‐photosensitive strategy under visible light was successfully developed. Preliminary mechanistic studies illustrated that isatin‐derived imines can be directly excited by generate strong oxidant states, facilitating subsequent single‐electron transfer (SET) processes with Hantzsch esters afford corresponding α‐amino radical intermediates. Thus, these radicals promote Giese addition or radical/radical cross‐coupling reactions furnish diverse functionalized 3‐substituted 3‐aminooxindoles in high yields.

Язык: Английский

Organocatalytic Michael Addition of Unactivated α-Branched Nitroalkanes to Afford Optically Active Tertiary Nitrocompounds DOI Creative Commons
Beñat Lorea, Ane García‐Urricelqui, José M. Odriozola

и другие.

Organic Letters, Год журнала: 2023, Номер 25(48), С. 8590 - 8595

Опубликована: Ноя. 27, 2023

The direct, asymmetric conjugate addition of unactivated α-branched nitroalkanes is developed based on the combined use chiral amine/ureidoaminal bifunctional catalysts and a tunable acrylate template to provide tertiary nitrocompounds in 55–80% isolated yields high enantioselectivity (e.r. up 96:4). Elaboration ketol moiety thus obtained adducts allows fast entry not only carboxylic aldehyde derivatives but also nitrile compounds enantioenriched 5,5-disubstituted γ-lactams.

Язык: Английский

Процитировано

2
Kilogram-Scale Preparation of the Amino Alcohol Fragment of Selgantolimod by Enzymatic Resolution of an α,α-Disubstituted Amino Ester DOI
Adam B. Weinstein,

Florence J. Bachrach,

Amy M. Cagulada

и другие.

Organic Process Research & Development, Год журнала: 2023, Номер 27(11), С. 2111 - 2122

Опубликована: Ноя. 2, 2023

The chiral amino alcohol (R)-2-amino-2-methylhexan-1-ol (1) is a key fragment in the synthesis of selgantolimod, TLR8 agonist that being evaluated for treatment hepatitis B infection. This report describes development robust and scalable targeted featuring hydrolase-catalyzed kinetic resolution an α,α-disubstituted ester. results highlight considerations substrate design enzymatic resolution, impact pH on unprotected ester derivative, implementation this within route to desired fragment.

Язык: Английский

Процитировано

1
A Disconnection for Rapid Access to Heterocyclic Benzylic Amines with Fully Substituted α-Carbons DOI
Shouliang Yang, Fen Wang,

Stephanie Scales

и другие.

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(6), С. 3926 - 3930

Опубликована: Март 5, 2024

2- or 4-Pyridyl benzylic amines represent a privileged motif in drug discovery. However, the formation of heterocyclic with fully substituted α-carbons can require execution lengthy synthetic routes, which limit their application. Addition various nucleophilic agents to Ellman's imines has been well established; however, there is no precedented literature reported for pyridyl-type nucleophiles, are very important medicinal chemistry. In this letter, we disclose development one-step synthesis from heteroaryl halides and sulfinyl imines. Starting 2,4-dibromopyridine, regioselective 4-pyridyl could be achieved by choosing toluene MTBE as solvent.

Язык: Английский

Процитировано

0
Dearomative Functionalization of Activated Quinolines: Transfer Hydrogenation/Cycloaddition Cascade to Construct α‐Tertiary Amines DOI Open Access
Suman Yadav,

Ruchir Kant,

Malleswara Rao Kuram

и другие.

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(20), С. 4219 - 4227

Опубликована: Авг. 7, 2024

Abstract Cascade dearomative functionalization is a robust protocol to convert flat arenes into medicinally relevant three‐dimensional architectures with added new functionality. Herein, cycloaddition for synthesizing tetrahydroquinoline‐embedded α‐tertiary amine scaffolds has been developed employing quinolinium salts and sulfonyl azides under metal‐free conditions. An underexplored mechanistically distinct pathway unveiled, creating quaternary‐center‐bearing skeletons by an group migration during the transfer hydrogenation cascade reaction. This approach provided broad substrate scope of from plethora C3‐substituted azides. The post‐synthetic modifications have further diversified core interesting scaffolds. Preliminary mechanistic studies suggested involvement aziridine ring formation C‐3 position quinoline generate core.

Язык: Английский

Процитировано

0
Visible Light‐Induced Umpolung Synthesis of 3,3‐Disubstituted Oxindoles via the Substrate‐Photosensitive Strategy DOI
H. J. Yang, Ting-Ting Wang,

Benhui Sui

и другие.

Chinese Journal of Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 25, 2024

Comprehensive Summary 3,3‐Disubstituted oxindoles, forming the core of extensive bioactive natural products and drugs, attract tremendous efforts to develop efficient methods for their preparation. Here, a photocatalyst‐free approach synthesis 3,3‐disubstituted oxindoles via substrate‐photosensitive strategy under visible light was successfully developed. Preliminary mechanistic studies illustrated that isatin‐derived imines can be directly excited by generate strong oxidant states, facilitating subsequent single‐electron transfer (SET) processes with Hantzsch esters afford corresponding α‐amino radical intermediates. Thus, these radicals promote Giese addition or radical/radical cross‐coupling reactions furnish diverse functionalized 3‐substituted 3‐aminooxindoles in high yields.

Язык: Английский

Процитировано

0