Palladium‐Catalyzed Enantioselective Cacchi Reaction: Asymmetric Synthesis of Axially Chiral 2,3‐Disubstituted Indoles

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(5), P. 2105 - 2109

Published: Nov. 22, 2019

We report herein the first examples of a palladium-catalyzed enantioselective Cacchi reaction for synthesis indoles bearing chiral C2-aryl axis. In presence catalytic amount Pd(OAc)2 and (R,R)-QuinoxP* ligand, N-aryl(alkyl)sulfonyl-2-alkynylanilides with arylboronic acids under oxygen atmosphere afforded enantioenriched 2,3-disubstituted in high yields enantioselectivity. The indole ring is constructed de novo this process complexation-induced chirality transfer proposed to account observed

Language: Английский

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Synthesis of Axially Chiral Styrenes through Pd‐Catalyzed Asymmetric C−H Olefination Enabled by an Amino Amide Transient Directing Group

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(16), P. 6576 - 6580

Published: Feb. 3, 2020

Abstract The atroposelective synthesis of axially chiral styrenes remains a formidable challenge due to their relatively lower rotational barriers compared the biaryl atropoisomers. Herein, we describe construction through Pd II ‐catalyzed C−H olefination, using bulky amino amide as transient auxiliary. Various were produced with good yields and high enantioselectivity (up 95 % yield 99 ee ). Carboxylic acid derivatives resulting showed superior enantiocontrol over counterparts in Co III enantioselective C(sp 3 )−H amidation thioamide. Mechanistic studies suggest that cleavage is enantioselectivity‐determining step.

Language: Английский

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Rhodium-Catalyzed Atroposelective Oxidative C–H/C–H Cross-Coupling Reaction of 1-Aryl Isoquinoline Derivatives with Electron-Rich Heteroarenes

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(37), P. 15678 - 15685

Published: Aug. 31, 2020

Rhodium(III)-catalyzed enantioselective oxidative C–H/C–H cross-coupling reaction between two arenes is disclosed. With the combination of a chiral CpRh(III) complex and carboxylic acid additive, direct coupling reactions 1-aryl isoquinoline derivatives electron-rich heteroarenes such as thiophenes, furans, benzothiophenes, benzofurans are realized via double C–H functionalization process. A series axially compounds obtained in excellent yields enantioselectivities (up to 99% yield ee). Mechanistic studies suggest that both bond cleavages may not be turnover-limiting step.

Language: Английский

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Generation of Heteroatom Stereocenters by Enantioselective C–H Functionalization

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(10), P. 9164 - 9177

Published: Aug. 30, 2019

C–H functionalization has been established as an efficient way to generate molecular complexity. The formation of stereogenic carbon atoms by asymmetric seen tremendous progress over the past decade. More recently, direct catalytic modification bonds powerfully applied noncarbon centers, which constitute a key design element biologically active molecules and chiral ligands for catalysis. This area was opened seminal report describing enantioselective silicon stereocenter. It rapidly expanded with advances in phosphorus(V) centers. Moreover, routes sulfur oxidation states IV (sulfoxides) VI (sulfoximines) have disclosed. Herein, we discuss methods using selective remote heteroatom center via inner-sphere activation mechanism.

Language: Английский

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Atroposelective Access to Oxindole-Based Axially Chiral Styrenes via the Strategy of Catalytic Kinetic Resolution

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(37), P. 15686 - 15696

Published: Aug. 26, 2020

Atroposelective synthesis of axially chiral molecules has attracted substantial attention from chemists because the importance such molecules. However, catalytic asymmetric styrenes or vinyl arenes is underdeveloped and challenging due to low rotational barrier weak configurational stability Therefore, development powerful strategies for atroposelective great importance. In this work, we have accomplished first access oxindole-based by strategy kinetic resolution, offered two kinds styrene derivatives in good diastereoselectivities (up 94:6 dr) excellent enantioselectivities 98% ee) with high selectivity factors (S up 106). This not only provides easy but also offers a robust method synthesizing bisamide bearing both axial central chirality. More importantly, added new class members atropisomeric family, especially family styrenes.

Language: Английский

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