Synthesis of Tetrasubstituted 1,4-Dicarbonyl (Z)-2,3-Dihaloalkenes via Electrophilic Halogenation of Alkynyl Hydrazones DOI
Akashdeep Sharma, Paru Jamwal, Ramani Gurubrahamam

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(39), P. 7236 - 7241

Published: Sept. 25, 2023

A highly practical and stereoselective route to 1,4-dicarbonyl 2,3-dihaloalkenes is presented. The strategy involves bench-stable unprotected alkynyl hydrazones commercially available N-halosuccinimides that provide γ-oxo-α,β-(Z)-dihaloenoates in excellent yields with complete Z-selectivity. protocol also furnishes vicinal dihaloalkenes two different halogen atoms. Also, a straightforward one-pot synthesis of dihaloenoates from readily accessible 2-oxo-3-butynoate demonstrated. In addition, potential synthetic transformations 4-oxo-2,3-dibromoenoates are explored, which include the valuable five- six-membered heterocycles.

Language: Английский

Electrophilic Halogenation of Allenoates and 3-Alkynoates: Synthesis of 1,4-Dicarbonyl (E)-3-Haloalkenes and Mechanistic Investigations DOI
Paru Jamwal, Yumnam Nganthoinganbi, Ming‐Kang Tsai

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Allenoates traditionally provide halobutenolides upon reaction with halonium ions via electrophile-assisted halolactonization. Herein, an unusual electrophilic halogenation of di- and trisubstituted allenoates 3-alkynoates is demonstrated N-halosuccinimides under DABCO promotion. The protocol affords densely functionalized 1,4-dicarbonyl 3-haloalkenes in good yields excellent (E)-stereoselectivity (up to 83% yield, >20:1 dr). are presumed form γ-haloallenoate intermediates, which further react the desired scaffolds. role nucleophilic base transformation demystified through control experiments computational studies. deliverables identified as synthons for various synthetic group transformations valuable targets biologically active pyridazine

Language: Английский

Citations

0
Electroreductive Carboxylation of Propargylic Acetates with CO2: Access to Tetrasubstituted 2,3-Allenoates DOI

Jing‐Hao Qin,

Zhiqiang Xiong,

Chaozhihui Cheng

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(51), P. 9176 - 9180

Published: Dec. 19, 2023

An electroreductive carboxylation of propargylic alcohols with CO2 and then workup TMSCHN2 to construct tetrasubstituted 2,3-allenoates is developed. This method allows the incorporation an external ester group into resulting allene system through electroreduction, carboxylation, deacetoxylation cascades. Mechanistically, electricity on/off experiments cyclic voltammetry analysis support preferential generation radical anion or 3-aryl acetate based on electron nature aryl rings.

Language: Английский

Citations

9
Synthesis of Tetrasubstituted 1,4-Dicarbonyl (Z)-2,3-Dihaloalkenes via Electrophilic Halogenation of Alkynyl Hydrazones DOI
Akashdeep Sharma, Paru Jamwal, Ramani Gurubrahamam

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(39), P. 7236 - 7241

Published: Sept. 25, 2023

A highly practical and stereoselective route to 1,4-dicarbonyl 2,3-dihaloalkenes is presented. The strategy involves bench-stable unprotected alkynyl hydrazones commercially available N-halosuccinimides that provide γ-oxo-α,β-(Z)-dihaloenoates in excellent yields with complete Z-selectivity. protocol also furnishes vicinal dihaloalkenes two different halogen atoms. Also, a straightforward one-pot synthesis of dihaloenoates from readily accessible 2-oxo-3-butynoate demonstrated. In addition, potential synthetic transformations 4-oxo-2,3-dibromoenoates are explored, which include the valuable five- six-membered heterocycles.

Language: Английский

Citations

3