(n+3)-Cyclization for the Formation of Benzo[7]annulene Derivatives via a [1,4]-Hydride Shift: A Novel Cyclization Mode Involving an Internal Redox Reaction DOI
Keiji Mori,

Jun Nagaki,

Tomoko Kawasaki‐Takasuka

et al.

Synlett, Journal Year: 2024, Volume and Issue: unknown

Published: March 14, 2024

Abstract We report a unique synthetic route to benzo[7]annulene derivatives. When benzylidene malonates having 1-(N,N-dialkylamino)alkyl group at the ortho-position are treated with stoichiometric amount of M(OTf)3 (M = Sc, Yb, Gd), three transformations ([1,4]-hydride shift/isomerization into an enamine/intramolecular Stork enamine acylation) proceed sequentially afford various derivatives in moderate chemical yields. To our knowledge, present reaction is first example internal redox involving [1,n]-hydride shift/(n+3)-cyclization process.

Language: Английский

Silyl-Group Boosted Internal Redox Reaction: Hydride Shift from an Aliphatic Secondary Position for the Formation of Six- and Seven-Membered Carbocycles DOI

Hiroto Okawa,

Tomoko Kawasaki‐Takasuka, Keiji Mori

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(8), P. 1662 - 1666

Published: Feb. 21, 2024

We report a hydride shift/cyclization reaction at the aliphatic secondary position (methylene group). The key to accomplishing this was employment of benzylidene malonate having silyl group β donor carbon. When corresponding malonates were treated with catalytic amount Al(OTf)3, [1,5]-hydride shift from simple proceeded smoothly afford silyl-group substituted tetralin derivatives in excellent chemical yields (up 98%). This system applied formation seven-membered carbocycles via [1,6]-hydride mediated process.

Language: Английский

Citations

5
Asymmetric Catalytic (3 + 2) Cyclization and Sequential Reaction to Construct Dihydrofuran- and Azepine-Based Spirooxindoles DOI

Qiliang Luo,

Yuqiao Zhou, Jing Zhang

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 22, 2025

The enantioselective formal (3 + 2) cyclization and sequential reaction of 2-malononitrile-substituted oxindoles with benzaldehydes ortho-aminobenzaldehydes were achieved by chiral N,N′-dioxide/metal complex Lewis acid catalysts. This protocol supplies facile efficient access to highly functionalized dihydrofuran- azepine-based spirooxindoles. Based on the control experiments deuterium labeling studies, interconversion diastereomeric intermediates under conditions reversible 1,5-H transfer step disclosed.

Language: Английский

Citations

0
Diversity-oriented synthesis of indole-fused scaffolds and bis(indolyl)methane from tosyl-protected tryptamine DOI
Liang Wang,

Xiaopei Song,

Fengxia Guo

et al.

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(14), P. 2824 - 2834

Published: Jan. 1, 2024

Diversity-oriented synthesis of indole-1,2-fused 1,4-benzodiazepines, tetrahydro-β-carbolines, and 2,2′-bis(indolyl)methanes is presented by control reaction sites.

Language: Английский

Citations

1
(n+3)-Cyclization for the Formation of Benzo[7]annulene Derivatives via a [1,4]-Hydride Shift: A Novel Cyclization Mode Involving an Internal Redox Reaction DOI
Keiji Mori,

Jun Nagaki,

Tomoko Kawasaki‐Takasuka

et al.

Synlett, Journal Year: 2024, Volume and Issue: unknown

Published: March 14, 2024

Abstract We report a unique synthetic route to benzo[7]annulene derivatives. When benzylidene malonates having 1-(N,N-dialkylamino)alkyl group at the ortho-position are treated with stoichiometric amount of M(OTf)3 (M = Sc, Yb, Gd), three transformations ([1,4]-hydride shift/isomerization into an enamine/intramolecular Stork enamine acylation) proceed sequentially afford various derivatives in moderate chemical yields. To our knowledge, present reaction is first example internal redox involving [1,n]-hydride shift/(n+3)-cyclization process.

Language: Английский

Citations

1