Annulation of CF₃–Imidoyl Sulfoxonium Ylides with 1,3-Dicarbonyl Compounds: Access to 1,2,3-Trisubstituted 5-Trifluoromethylpyrroles

Abstract

A lithium-bromide-promoted nucleophilic substitution/ annulation cascade reaction between CF 3 -imidoyl sulfoxonium ylides and 1,3-dicarbonyl compounds has been established, and the corresponding 1,2,3-trisubstituted 5-trifluoromethylpyrroles have been obtained in 27−78% yield. This reaction features a broad substrate scope and generates dimethyl sulfoxide and H 2 O as byproducts. * sı Supporting InformationThe Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.orglett.1c02598.Optimization experiments, general experimental procedures, crystallographic data, and NMR spectra for new compounds (PDF)Accession Codes CCDC 2074418−2074420 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk

Transition-Metal-, Additive-, and Solvent-Free [3 + 3] Annulation of RCF2-Imidoyl Sulfoxonium Ylides with Cyclopropenones to Give Multifunctionalized CF3-Pyridones

“…Recently, Wu documented a base-promoted [3 + 3] annulation of acyl sulfoxonium ylides with cyclopropenones to give 2-pyrones . In our ongoing interest in sulfoxonium ylide chemistry, we questioned whether it is possible to construct new C–C bonds via nucleophilic substitution of carbanions to sulfoxonium ylides without the participation of a transition metal . Recently, we documented that electron-deficient sulfoxonium ylides are more prone to be attacked by nucleophiles than the electron-rich ones .…”

Enantioselective Access to C-N Axially Chiral Isoquinolones via Dynamic Kinetic Transformation of Carbene Reagents: Unique Chiral Induction Enabled by Dual Role of the Catalyst

“…Our design boils down to development of new coupling reagents that are both bulky and reactive. To reconcile these seemingly contradictive criteria, we employed a bifunctional carbene reagent such as CF3-imidoyl sulfoxonium ylides (TFISYs) [57][58][59][60][61][62][63][64][65] bearing a proximal nucleophilic imine nitrogen as well as a bulkyl N-aryl group (Scheme 1c). Consequently, a secondary amide bearing an electrophilic directing group [66][67][68][69][70][71] was applied as the C-H substrate.…”

Reactions of 1-Trifluoromethylprop-2-yne 1-Iminium Salts with Nitroanilines: Synthesis of 4-Trifluoromethylnitroquinolines and 1,2,3-Trisubstituted 5-Trifluoromethylpyrroles

“…23 Other multiply substituted -CF3-pyrroles have recently been prepared using several different trifluoromethylated building blocks, namely 5-azido- 33 or 5-bromo-4-alkoxy(or amino)-1,1,1trifluoro-pent-3-en-2-ones, 34 CF3-imidoyl sulfoxonium ylides. 35 and 1-(3,3,3-trifluoro-2,2-dihydroxypropyl)pyridin-1-ium bromide. 36 In conclusion, we have found that various 2-R-4-(trifluoromethyl)quinolines bearing an additional nitro group at ring position 6, 7 or 8 can be prepared from 1-CF3-prop-2-yne 1iminium triflates and mononitroanilines in good to high yields.…”

“…32 Anyway, the reaction course is different from our recently published, triphenylphosphane promoted synthesis of -trifluoromethylpyrroles from propyniminium salts 1, which proceeds via 3-dimethylamino-3-trifluoromethylallenyl phosphonium salts. 23 Other multiply substituted -trifluoromethylpyrroles have recently been prepared using several different trifluoromethylated building blocks, namely 5-azido- 33 or 5-bromo-4-alkoxy(or amino)-1,1,1-trifluoro-pent-3-en-2ones, 34 trifluoromethylimidoyl sulfoxonium ylides, 35 and 1-(3,3,3-trifluoro-2,2-dihydroxypropyl)pyridin-1-ium bromide. 36 In conclusion, we have found that various 2-R-4-(trifluoromethyl)quinolines, bearing an additional nitro group at ring position 6, 7 or 8, can be prepared from 1-trifluoromethylprop-2-yne 1-iminium triflates and mononitroanilines in good to high yields.…”