Electrocatalytic Asymmetric Nozaki–Hiyama–Kishi Decarboxylative Coupling: Scope, Applications, and Mechanism

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(7), P. 4872 - 4882

Published: Feb. 7, 2024

The first general enantioselective alkyl-Nozaki-Hiyama-Kishi (NHK) coupling reactions are disclosed herein by employing a Cr-electrocatalytic decarboxylative approach. Using easily accessible aliphatic carboxylic acids (via redox-active esters) as alkyl nucleophile synthons, in combination with aldehydes and enabling additives, chiral secondary alcohols produced good yield high enantioselectivity under mild reductive electrolysis. This reaction, which cannot be mimicked using stoichiometric metal or organic reductants, tolerates broad range of functional groups is successfully applied to dramatically simplify the synthesis multiple medicinally relevant structures natural products. Mechanistic studies revealed that this asymmetric e-NHK reaction was enabled catalytic tetrakis(dimethylamino)ethylene, acts key mediator mediate electroreduction Cr

Language: Английский

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Nickel-Catalyzed Reductive Cross-Coupling of Propargylic Acetates with Chloro(vinyl)silanes: Access to Silylallenes

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 2885 - 2894

Published: Feb. 14, 2024

Because of their various reactivities, propargyl acetates are refined chemical intermediates that extensively applied in pharmaceutical synthesis. Currently, reactions between and chlorosilanes may be the most effective method for synthesizing silylallenes. Nevertheless, owing to adaptability selectivity substrates, transition metal catalysis is difficult achieve. Herein, nickel-catalyzed reductive cross-coupling substituted vinyl synthesis tetrasubstituted silylallenes described. Therein, metallic zinc a crucial reductant effectively enables two electrophilic reagents selectively construct C(sp2)–Si bonds. Additionally, Ni-catalyzed mechanism involving radical process proposed on basis deuteration-labeled experiments.

Language: Английский

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Synthesis of Alkynylsilanes: A Review of the State of the Art

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(11), P. 2382 - 2431

Published: April 12, 2024

Abstract This contribution offers a comprehensive overview of methods for forging sp C−Si bonds. Over time, alkynylsilanes (silylacetylenes), once considered mere byproducts hydrosilylation processes, have become essential building blocks in organic synthesis. literature review traces the evolution their synthesis, from traditional methodologies relying on organolithium and organomagnesium compounds to more advanced cross‐coupling reactions involving hydro‐ carbosilanes. Focused primarily past 25 years (2000–2024), it also extensively references significant historical breakthroughs. By analyzing synthetic methodologies, not only survey current state knowledge but identifies areas improvement. Furthermore, emphasize importance 1‐alkynylsilanes (1‐silyl‐1‐alkynes), selected applications these are highlighted, confirming potential

Language: Английский

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Conversion of waste poly(vinyl chloride) to branched polyethylene mediated by silylium ions

Chemical Science, Journal Year: 2024, Volume and Issue: 15(23), P. 8766 - 8774

Published: Jan. 1, 2024

Lewis acidic silylium ions are used to completely remove Cl from poly(vinyl chloride) (PVC) in clean and commercial products through hydrodechlorination. Reaction conditions were found impact the branching resulting polyethylene (PE).

Language: Английский

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Electrochemical Decarboxylative Silylation of α,β-Unsaturated Carboxylic Acids

Organic Letters, Journal Year: 2023, Volume and Issue: 25(24), P. 4562 - 4566

Published: June 14, 2023

An electrochemical method for the decarboxylative silylation of α,β-unsaturated carboxylic acids was developed. A variety alkenylsilanes could be obtained in satisfactory yields and excellent selectivities under external oxidant- metal-free conditions. Mechanistic studies showed that formation silyl radical mediated by NHPI, which produces hydrogen atom transfer (HAT) reagent phthalimide N-oxyl (PINO) via multiple-site concerted proton-electron (MS-CPET).

Language: Английский

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Understanding the competition between hydrodechlorination and Friedel–Crafts alkylation in PVC dechlorination with silylium ions

Polymer Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Combined hydrodechlorination and Friedel–Crafts alkylation of poly(vinyl chloride) can contain secondary reactions that modify thermal properties products, depending on the arene substrate reaction temperature.

Language: Английский

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Electrochemical synthesis of allenyl silanes and allenyl boronic esters

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: May 17, 2025

Allenyl silanes and boronates are pivotal building blocks in organic synthesis. Nevertheless, their synthesis requires the manipulation of transition metal or highly reactive species. Hence, development more sustainable protocol is sought after. Here we show electrochemical allenyl boronic esters. This catalyst-free method proceeds under mild reaction conditions. The for shows an excellent efficiency a good functional group tolerance. isolated yields (28 examples, 45-95% yields) without use catalyst A similar developed boronates, which obtained low to moderate (13 5-55% yields). Finally, mechanism based on oxidative generation silyl boryl radicals suggested access these classes allenes.

Language: Английский

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Allylsilane as a versatile handle in photoredox catalysis

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(35), P. 4633 - 4647

Published: Jan. 1, 2024

This review briefly summarizes the utilization of allylsilane in photoredox catalysis. It highlights underlying mechanisms for formation C–C/C–heteroatom bond with various functionalities mild conditions high selectivity.

Language: Английский

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Nickel‐Catalyzed Intramolecular Hydrosilylation of Alkynes: Embracing Conventional and Electrochemical Routes

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(36)

Published: April 26, 2024

Abstract Nickel‐catalyzed intramolecular hydrosilylation can be efficiently achieved with high regio‐ and stereoselectivities through two distinct methodologies. The first approach utilizes a conventional method, involving the reduction of nickel salt (NiBr 2 ‐2,2’‐bipyridine) using manganese metal. second method employs one‐step electrochemical reaction, utilizing sacrificial anode process NiBr bipy catalysis. Both methods yield silylated heterocycles in good to yields syn ‐ exo dig cyclization process. Control experiments molecular electrochemistry (cyclic voltammetry) provided further insights into reaction mechanism.

Language: Английский

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Electrochemically Induced Synthesis of β‐Ketosulfones from Enol Acetates and Sodium Sulfinates

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(36)

Published: Sept. 1, 2024

Abstract β‐Ketosulfones were synthesized from enol acetates and sodium sulfinates under electrochemical conditions. The starting can act both as the supporting electrolyte source of S‐centered radicals, allowing electrolysis to proceed without external salt. Side reactions acetates’ oxidation are not observed, developed process is quite selective. proposed sulfonylation compatible with a wide range initial sulfinates. On basis literature data, control experiments, CV studies, presumable reaction pathway suggested. key intermediates sulfonyl radical, C‐centered benzylic β‐acetoxy‐β‐hydroxysulfone.

Language: Английский

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