Synthesis of Novel Cyclic Nitrones with gem‐Difluoroalkyl Side Chains Through Cascade Reactions. Issue 35 (3rd September 2020)

• Record Type: Journal Article
• Authors: Soulieman, Ali; Ibrahim, Rima; Barakat, Zeinab; Gouault, Nicolas; Roisnel, Thierry; Boustie, Joel; Grée, René; Hachem, Ali
• Is Part Of: European journal of organic chemistry. Issue 35(2020)
• Page Start: 5741
• Page End: 5751
• Publication Date: 2020-09-03
• Subjects: Fluorine -- Nitrones -- Cascade reactions -- Propargylic fluorides -- Nitroalkanes; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202000972
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : New five‐membered cyclic nitrones with gem ‐difluoroalkyl groups in γ‐position have been prepared by a 3‐step sequence starting from propargylic alcohols. This domino process involves a base‐mediated isomerization reaction to enones, which are trapped in situ by nitroalkane anions. In a final step, starting from these key precursors, a reduction‐cyclization process affords the target molecules. Mono‐ and bicyclic nitrones have been prepared by this route which allows, as well, the synthesis of nitrones with functional groups in terminal position of the side chain. Abstract : New mono‐ and bicyclic nitrones containing a CF2 group have been efficiently synthetized starting from propargylic fluorides. The key steps involve isomerization of propargylic alcohols to enones, followed by nucleophilic addition of nitro alkane anions and then intramolecular Michael additions. The last step is a reductive cyclisation from the nitro group.