Asymmetric Synthesis of Seven‐Membered Lactams: Recent Advances and Future Perspectives

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(41)

Published: July 17, 2024

Abstract The optically active lactams represent an important structural motif and present in a wide range of natural products, biologically compounds drugs. Compared to the synthesis chiral five‐ six‐membered lactams, asymmetric construction seven‐membered often presents challenge due their consequential entropic enthalpic barriers. Over past few decades, substantial efforts have been devoted this field chemists developed various efficient strategies for preparation lactams. In review, we will highlight recent advances enantioselective formation discussion be logically divided into three parts according reaction mode. aim review is familiarize Reader with new synthetic opportunities offered by these interesting methodologies.

Language: Английский

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Enantioselective Synthesis of Biphenyl‐Bridged ϵ‐Sultams by Organocatalytic Mannich Reactions of Cyclic N‐Sulfonylimines with Unactivated Ketones

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(6)

Published: Nov. 8, 2023

A highly enantioselective Mannich reaction of biphenyl-bridged seven-membered cyclic N-sulfonylimines with methyl alkyl ketones is disclosed in this study. The was performed under organocatalysis by using a quinine-derived primary amine as the catalyst combination Brønsted acid co-catalyst. High yields (up to 89 %) and excellent enantioselectivities 97 % ee) were observed. For containing larger substituent, specific regioselective addition C=N bond favored at group. On contrary, smaller substituent or hydroxyacetone substrates gave major syn selective products methylene

Language: Английский

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Benzo‐fused Nitrogen Heterocycles by Asymmetric Ring Expansion and Stereochemically Retentive Re‐contraction of Cyclic Ureas

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(12)

Published: Jan. 23, 2024

Abstract Benzo‐fused nitrogen heterocycles are common features of bioactive molecules, and the enantioselective synthesis their substituted analogues is an important goal. In this paper we demonstrate a practical mechanistically intriguing approach to 1‐arylbenzazepines analogues. The reaction sequence starts with asymmetric migratory ring expansion indoline, tetrahydroquinoline, or tetrahydrobenzazepine ureas on treatment chiral lithium amide base. Treatment ring‐expanded acid triggers two‐atom contraction—an ‘azatropic shift’ in which one urea displaces other—with almost complete retention stereochemistry. Aminolysis products provides enantioenriched 1‐aryl‐tetrahydrobenzazepine derivatives congeners, including analogue intermediate drug solifenacin. Deuteration, situ IR, DFT studies provide evidence for mechanisms steps.

Language: Английский

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Direct construction of biaryl-bridged 8–11 membered N-heterocycles via gold(i)-catalyzed intramolecular [4 + 2] benzannulation of N-tethered diynyl benzaldehydes

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(13), P. 3280 - 3287

Published: Jan. 1, 2023

A method for the expeditious assembly of a diverse range biaryl-bridged 8–11 membered N -heterocycles that relies on gold( i )-catalyzed intramolecular [4 + 2] benzannulation -tethered diynyl benzaldehydes is described.

Language: Английский

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Construction of central and axial chirality via Pd(II)/Bim-catalyzed asymmetric dearomative Michael reaction of polycyclic tropones

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(67), P. 8908 - 8911

Published: Jan. 1, 2024

A highly enantioselective Pd/Bim-catalyzed dearomative Michael reaction applying polycyclic tropones as non-benzenoid aromatic acceptors and arylboronic acids aryl pronucleophiles has been developed. The bridged biaryls bearing central axial chirality, including pentacyclic cyclohepta[

Language: Английский

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