Direct C(sp3)-H functionalization with aryl and alkyl radicals as intermolecular hydrogen atom transfer (HAT) agents

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Recent years have witnessed the emergence of direct intermolecular C(sp

Language: Английский

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Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes

Beilstein Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 21, P. 947 - 954

Published: May 19, 2025

We present the first examples of alkene amino-sulfonoxylation reactions that leverage unique reactivity carbamate tethered N -alkoxy nitrenium ions. In almost all cases examined, deliver product with exquisite regioselectivity and diastereoselectivity. The protocols followed are operationally very simple only use commercial I(III) reagents sulfonic acids, amounting to a metal-free protocol for amino-oxygenation. No special precautions need be taken exclude air or ambient moisture, products amenable further transformations.

Language: Английский

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A strategy for the controllable generation of organic superbases from benchtop-stable salts

Chemical Science, Journal Year: 2024, Volume and Issue: 15(26), P. 10018 - 10026

Published: Jan. 1, 2024

Organic superbases are a distinct class of strong base that enable numerous modern reaction applications. Despite their great synthetic potential, widespread use and study limited by air sensitivity difficult preparation. To address this, we report air-stable carboxylate salts BTPP P2-t-Bu phosphazene that, when added to solution with an epoxide, spontaneously generate freebase. These systems function as effective precatalysts stoichiometric prereagents for superbase-promoted addition, substitution polymerization reactions. In addition improving the synthesis, shelf stability, handling recycling phosphazenes, this approach enables precise regulation rate generation in situ. The activation strategy effectively mimics manual slow techniques, allowing control over reaction's or induction period improvement reactions require but also sensitive its presence, such Pd-catalyzed coupling

Language: Английский

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Catalyst-Free Direct Olefin Halo-Hydroxylamination: Rapid Syn-thesis of Multifunctional Hydroxylamines (MFHAs) for Structurally Complex Amines and N-Heterocycles

Published: June 4, 2024

Herein, we introduce a novel and powerful alkene difunctionalization process where anomeric amides (e.g., N-halogenated O-activated hydroxylamines) react directly with olefins, without the use of catalysts or additives, to yield corresponding N-haloalkyl hydroxylamines. These multifunctional hydroxylamines (MFHAs), containing both alkyl halide hydroxylamine moieties, are convenient building blocks/electrophilic aminating reagents for synthesis structurally complex N-unprotected secondary amines N-heterocycles. Both activated unactivated alkenes (including cyclic acyclic dienes, enynes) effectively converted difunctionalized derivatives excellent atom economy. The versatility MFHAs was demonstrated through various nitrogen-containing molecules.

Language: Английский

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Cu⁰-Promoted Truce–Smiles Rearrangement for Aryl-Difluoromethylenation of C═C Bonds via a Reductive Radical–Polar Crossover Process

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(19), P. 13947 - 13952

Published: Sept. 16, 2024

An efficient Cu

Language: Английский

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Taming Tethered Nitreniums for Alkene Functionalization Reactions

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(20), P. 15352 - 15357

Published: Oct. 10, 2024

We present the first examples of amino-trifluoroacetoxylations alkenes using N-alkoxy carbamate tethers. Hypervalent iodine oxidants mediate this transformation, providing a "green" alternative to existing intramolecular amino-hydroxylation protocols which use toxic metals such as osmium. In all cases examined, reaction is regioselective and stereospecific, with geometry starting alkene controlling diastereomeric outcome. By analogy prior art from our own observations, we posit that transient nitrenium species serves key intermediate.

Language: Английский

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Enabling Unfavorable Hydroamination Reactions Using a Chemoselective N–O Bond Reduction

Organic Letters, Journal Year: 2024, Volume and Issue: 26(46), P. 9885 - 9890

Published: Nov. 7, 2024

Despite major advances, intramolecular alkene hydroamination reactions often face limitations. Herein, a redox-enabled process featuring oxidation of an amine to hydroxylamine, concerted step, followed by catalytic reduction

Language: Английский

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Visible-Light Induced and Iron Peroxo-Promoted Radical Difunctionalization of Alkene for the Synthesis of β-Ketosulfone and α-Chloroketone

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 26, 2024

In this work, a switchable synthesis of β-ketosulfone and α-chloroketone through radical difunctionalization alkenes is reported. The transformation works well under iron peroxo species/photoredox dual catalysis an open-flask atmosphere, the reaction highlighted with good yields broad scope. Mechanism studies show that initiated by formal [4 + 2] cyclization sulfonyl in regioselective manner.

Language: Английский

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