Bifunctional sulfilimines enable synthesis of multiple N-heterocycles from alkenes

• Published in: Nature chemistry Vol. 14; no. 8; pp. 898 - 904
• Main Authors: Cheng, Qiang, Bai, Zibo, Tewari, Srija, Ritter, Tobias
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2022; NATURE PORTFOLIO; Nature Publishing Group
• Subjects: 639/638/403/933; 639/638/439/890; 639/638/549/933; 639/638/77/890; Alkenes; Alkenes - chemistry; Analytical Chemistry; Biochemistry; Catalysis; Chemical reactions; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chemistry, Multidisciplinary; Chemistry/Food Science; Construction; Cyclization; Imines - chemistry; Inorganic Chemistry; Modular construction; Nitrogen; Nitrogen - chemistry; Organic Chemistry; Photoredox catalysis; Physical Chemistry; Physical Sciences; Reagents; Science & Technology; AMINATION STRATEGIES; THIOMORPHOLINES; AMINOFLUORINATION; OLEFINS; GENERATION; RADICALS; CLEAVAGE; CARBOAMINATION; C-H BONDS; AMINOHYDROXYLATION
• ISSN: 1755-4330; 1755-4349; 1755-4349
• DOI: 10.1038/s41557-022-00997-y

Intramolecular cyclization of nitrogen-containing molecules onto pendant alkenes is an efficient strategy for the construction of N-heterocycles, which are of paramount importance in, for example, pharmaceuticals and materials. Similar intermolecular cyclization reactions, however, are scarcer for nitrogen building blocks, including N-centred radicals, and divergent and modular versions are not established. Here we report the use of sulfilimines as bifunctional N-radical precursors for cyclization reactions with alkenes to produce N-unprotected heterocycles in a single step through photoredox catalysis. Structurally diverse sulfilimines can be synthesized in a single step, and subsequently engage with alkenes to afford synthetically valuable five-, six- and seven-membered heterocycles. The broad and diverse scope is achievable by a radical-polar crossover annulation enabled by the bifunctional character of the reagents, which distinguishes itself from all other N-centred-radical-based reactions. The modular synthesis of the sulfilimines allows for larger structural diversity of N-heterocycle products than is currently achievable with other single cyclization methods. Intermolecular cyclization reactions using nitrogen-containing building blocks are scarce. Now, bifunctional sulfilimines have been shown to enable the modular construction of a diverse range of N-heterocycles by reacting with alkenes in a single photocatalysed step. Both sulfilimines and alkenes are easily accessible, providing access to a wide range of N-heterocycles with different ring types, ring sizes and substituents on the skeleton.