Organic Letters, Journal Year: 2021, Volume and Issue: 23(11), P. 4094 - 4098
Published: May 13, 2021
We report here a multicomponent protocol to assemble several polycyclic dihydropyran-fused tetrahydroquinoline structures with excellent diastereoselectivity. This procedure employs simple feedstocks accomplish series of diverse structures, which is difficult attain by traditional sequences.
Language: Английский
Chemical Communications, Journal Year: 2020, Volume and Issue: 56(17), P. 2586 - 2589
Published: Jan. 1, 2020
An efficient enantioselective dearomatization of 2-nitrobenzofurans was realized via an organocatalyzed one-step Michael addition process. This method provides a facile strategy to access range structurally diverse 3,3'-disubstituted oxindoles, which feature intriguing combination two privileged motifs including 3-pyrrolyl-substituted-oxindoles and 2,3-dihydrobenzofurans substructures, in excellent results.
Language: Английский
Citations
31
Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(21), P. 5294 - 5304
Published: Jan. 1, 2019
An efficient Ph2PMe-catalyzed dearomative (3 + 2) annulation of 2-nitrobenzofurans, 2-nitrobenzothiophenes, and 3-nitrobenzothiophenes with allenoates is reported.
Language: Английский
Citations
30
Organic Letters, Journal Year: 2020, Volume and Issue: 22(8), P. 3114 - 3118
Published: April 7, 2020
A sequential [4 + 2]/[2 1] annulation of α-aryl vinylsulfoniums with 2-aminochalcones and 2-(2-aminobenzylidene)-1H-indene-1,3(2H)-dione is reported that affords a series cyclopropane-fused tetrahydroquinolines. The salient features this novel practical transformation include high efficiency, transition-metal-free nature, operational simplicity, outstanding functional group tolerance.
Language: Английский
Citations
30
Beilstein Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 17, P. 2585 - 2610
Published: Oct. 18, 2021
Nitrogen-containing scaffolds are ubiquitous in nature and constitute an important class of building blocks organic synthesis. The asymmetric aza-Michael reaction (aza-MR) alone or tandem with other reaction(s) is synthetic tool to form new C–N bond(s) leading developing libraries diverse types bioactive nitrogen compounds. synthesis application a variety organocatalysts for accomplishing highly useful syntheses without causing environmental pollution compliance ‘Green Chemistry” has been landmark development the recent past. Application many these extended aza-MR during last two decades. present article overviews literature published 10 years concerning amines amides catalysed by organocatalysts. Both organocatalysts, i.e., those acting through non-covalent interactions working covalent bond formation have applied aza-MR. Thus, review includes examples wherein cinchona alkaloids, squaramides, chiral amines, phase-transfer catalysts bifunctional thioureas used, which activate substrates hydrogen formation. Most reactions accompanied high yields enantiomeric excesses. On hand, N-heterocyclic carbenes pyrrolidine derivatives such as iminium ions also included. Wherever possible, comparison made between efficacies various
Language: Английский
Citations
26
Molecules, Journal Year: 2024, Volume and Issue: 29(5), P. 1163 - 1163
Published: March 5, 2024
An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions affords a series benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields (up 98%) with perfect diastereoselectivities (all cases > 20:1 dr). The scale-up synthesis versatile derivatizations demonstrate the potential synthetic application protocol. A plausible mechanism is also proposed account for observed process. work represents first instance N-triggered 2-nitrobenzofurans.
Language: Английский
Citations
3
Organic Letters, Journal Year: 2024, Volume and Issue: 26(13), P. 2623 - 2628
Published: March 24, 2024
An efficient dearomative cyclization of 2-nitrobenzofurans via a thiol-triggered tandem Michael addition/intramolecular Henry reaction has been developed. A range thiochromeno[3,2-b]benzofuran-11-ols and tetrahydrothieno[3,2-b]benzofuran-3-ols could be obtained in up to 99% yield >20:1 dr. The valuable thiochromone fused benzofurans prepared with the 2-mercaptobenzaldehyde reaction/rearomatization/oxidative dehydrogenation process one-pot two-step operation. mechanism for was tentatively proposed.
Language: Английский
Citations
3
Organic Letters, Journal Year: 2020, Volume and Issue: 22(18), P. 7088 - 7093
Published: Aug. 28, 2020
The first catalytic enantioselective dearomatization/rearomatization of 2-nitroindoles triggered by the Michael addition 3-monosubstituted oxindoles was established. A wide range 3-indolyl-3'-alkyloxindoles (up to 99% yield, 97% ee) and 3-indolyl-3'-aryloxindoles 95% were obtained using an organocatalyst. This method provides unprecedented strategy access structurally diverse 3,3'-disubstituted bearing a sterically congested triaryl-containing all-carbon quaternary stereocenter. utility this approach verified formal synthesis cyclotryptamine alkaloids.
Language: Английский
Citations
25
Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 28(2)
Published: Oct. 29, 2021
The application of dinuclear zinc catalysts in a dearomatization reaction has been developed. Catalytic asymmetric [3+2] annulations 2-nitrobenzofurans or 2-nitrobenzothiophenes with CF3 -containing N-unprotected isatin-derived azomethine ylides catalyzed by are realized excellent diastereomer ratios (dr) >20 : 1 and enantiomeric excess (ee) up to 99 %. This protocol provides practical, straightforward access structurally diverse pyrrolidinyl spirooxindoles containing 2,3-fused-dihydrobenzofuran (or dihydrobenzothiphene) moiety, four contiguous stereocenters. Reactions can be performed on gram scale. absolute configuration products is confirmed X-ray single crystal structure analysis, possible mechanism proposed.
Language: Английский
Citations
23
Asian Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 10(6), P. 1345 - 1376
Published: April 19, 2021
Abstract Chiral analogues of squaramides have been fruitful in organocatalyzed asymmetric reactions over last decade. Alongside other H‐bonding catalysts like ureas, thioureas: proved to be efficient for the formation acyclic and cyclic chiral molecules. A wide range molecules bearing multiple functionalities stereocenters synthesized by using several bifunctional as catalysts. These perform base utilizing basic N atom their extension help stereoinduction forming H‐bonds with suitable H‐bond acceptors. The present review focuses on assembling recent progresses synthesis five six membered rings promoted squaramides. handful articles published research groups documenting construction five‐ six‐membered part interesting complex molecular architectures. Different methodologies conventional formal cycloadditions or cascade engineered through assistance fabricate carbo‐ heterocycles. This also includes dual cooperative catalytic system which squaramide is one
Language: Английский
Citations
21
European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(18)
Published: April 5, 2022
Abstract Dearomatization reactions employing simple aromatic compounds have showcased remarkable progress in the recent decade and emerged as one of most straightforward powerful tools for creation highly functionalized, three‐dimensional molecular frameworks commonly encountered medicinal chemistry life sciences. Among use, nitro(hetero)arenes, which feature a less pronounced character due to presence electron‐withdrawing nitro group, been extensively used different types dearomatization reactions. The dearomative annulation reaction serves versatile method construction complex polycyclic systems. This overview presents brief summary impressive advances nitro(hetero)arenes provides some inspirations future research.
Language: Английский
Citations
16