Work

Enantioselective NHC-Catalyzed Annulation via Umpolung for the Construction of Hydroxylamine Architectures with Variable Ring Sizes

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide An efficient and highly enantioselective organocatalytic annulation for the synthesis of chiral hydroxylamine-containing heterocycles is described. The N -heterocyclic carbene (NHC)-catalyzed reaction successfully engages traditionally inert keto-oxime ethers as electrophiles in an intramolecular cyclization with in situ generated Breslow intermediates. This protocol overcomes the inherent challenges of this substrate class, such as low C═N bond electrophilicity and potential N–O bond cleavage, to deliver diverse five- and six-membered N–O frameworks in excellent yields (up to 99%) and enantioselectivities (up to >99% ee). This work provides a powerful, metal-free strategy to access valuable chiral building blocks and significantly expands the reactivity scope of keto-oximes in asymmetric catalysis.

Source: Organic Letters

DOI: 10.1021/acs.orglett.5c02576

Authors: Izabela Barańska, Monika Radosińska, Liliana Dobrzańska, Krzysztof Dzieszkowski, Zbigniew Rafiński

Institutions: Nicolaus Copernicus University, Jagiellonian University

Language: English

Topic: N-Heterocyclic Carbenes in Organic and Inorganic Chemistry

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Narodowe Centrum Nauki