Nitrative Difunctionalization of Alkenes via Cobalt-Mediated Radical Ligand Transfer and Radical-Polar Crossover Photoredox Catalysis

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(24), P. 16136 - 16147

Published: Dec. 1, 2023

Herein, we report the rational design of a modular dual photoredox and cobalt catalysis paradigm for difunctionalization unsaturated hydrocarbons, unlocking synthesis valuable but challenging 1,2-halonitroalkane substrate class. The protocol relies on use redox-active organic nitrating reagent N-nitrosuccinimide as source nitryl radicals cobalt-mediated radical ligand transfer (RLT) methodology to form carbon–halogen bond. This synergistic cooperation between photocatalyst high-valence metal center occurs under mild reaction conditions is capable delivering 1,2-chloronitro- 1,2-bromonitroalkanes in single chemical operation while exhibiting high functional-group tolerance exclusive regioselectivity variety olefins. Mechanistic studies based both experimental spectroscopic analysis provided insights into nature this catalytic halo-nitration process including evidence halogen catalyst. Furthermore, employing net-neutral radical/polar crossover (RPC) approach cobalt-free allowed us accommodate external protic nucleophiles, thiols, alcohols, acids, and, notably, substituted amines. Highly functionalized olefin scaffolds also successfully underwent nitrative difunctionalization, demonstrating viability these protocols late-stage functionalization bioactive molecules.

Language: Английский

Mechanochemistry Drives Alkene Difunctionalization via Radical Ligand Transfer and Electron Catalysis

Advanced Science, Journal Year: 2024, Volume and Issue: 11(29)

Published: June 3, 2024

Abstract A general and modular protocol is reported for olefin difunctionalization through mechanochemistry, facilitated by cooperative radical ligand transfer (RLT) electron catalysis. Utilizing mechanochemical force catalytic amounts of 2,2,6,6‐tetramethylpiperidinyloxyl (TEMPO), ferric nitrate can leverage nitryl radicals, nitrooxy‐functional group via RLT, mediate an catalysis cycle under room temperature. diverse range activated unactivated alkenes exhibited chemo‐ regioselective 1,2‐nitronitrooxylation solvent‐free or solvent‐less conditions, showcasing excellent functional tolerance. Mechanistic studies indicated a significant impact mechanochemistry highlighted the nature this nitrative process.

Language: Английский

Ipso-Nitration of Boronic Esters Enabled by Ferric Nitrate Nonahydrate (Fe(NO₃)₃·9H₂O) in HFIP

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

Published: March 13, 2025

We describe in this work an operationally facile and generally applicable ipso-nitration of boronic esters by Fe(NO3)3·9H2O hexafluoroisopropanol (HFIP), allowing us fast access to various nitroarenes that are currently difficult obtain via traditional electrophilic C–H nitrations. In contrast previous deborylative ipso-nitrations, new protocol utilized less reactive more stable organoboron reagents therefore had significantly improved substrate scope functional group tolerance, which was exemplified the late-stage natural products, pharmaceuticals, biologically active molecules.

Language: Английский