Synthesis of N-Sulfonyl- and N-Acylpyrroles via a Ring-Closing Metathesis/Dehydrogenation Tandem Reaction

Abstract

N-Sulfonyl- and N-acylpyrroles were synthesized via olefin ring-closing metathesis of diallylamines and in situ oxidative aromatization in the presence of the ruthenium Grubbs catalyst and a suitable copper catalyst. In the presence of Cu(OTf)2 and CuBr2, the reaction afforded N-sulfonyl- and N-acylpyrroles, respectively, in one pot. Under an oxygen atmosphere, the reaction went smoothly without the need of hydroperoxide oxidants. This protocol possesses many advantages, such as using a nonhazardous oxidant and readily available starting materials, operating in one pot, and showing a broad substrate scope.

Toward Biomass-Based Organic Electronics: Continuous Flow Synthesis and Electropolymerization of N-Substituted Pyrroles

“…To further characterize the obtained materials, the FTIR spectra of the monomers were compared with the spectra of their corresponding deposited films on graphite foil (Figure ). The spectra of the monomers were in accordance with previously reported data. , The absorption lines at 3144–3046 cm –1 (aromatic C–H stretching) and 1600–1320 cm –1 (CC, C–N stretching of aromatic units) were observed. In the monomer spectra, the signals at 1015 and 715 cm –1 are characteristic of out-of-plane vibrations of the C–H bond in the unsubstituted pyrroles.…”

“…The spectra of the monomers were in accordance with previously reported data. 41,42 The absorption lines at 3144− 3046 cm −1 (aromatic C−H stretching) and 1600−1320 cm −1 (C�C, C−N stretching of aromatic units) were observed. In the monomer spectra, the signals at 1015 and 715 cm −1 are characteristic of out-of-plane vibrations of the C−H bond in the unsubstituted pyrroles.…”

Palladium-Catalyzed Reaction of Indolines with Dihydropyrroles: Access to N-Alkylated Indoles

“…Unless otherwise specified, all manipulations were performed in air. 1-Acyl-2,3-dihydro-1 H - pyrroles and 1-acyl-2,5-dihydro-1 H -pyrroles were prepared according to the literature methods. Other chemicals and solvents were purchased from commercial vendors and used as received.…”

Application of Olefin Metathesis in the Synthesis of Carbo- and Heteroaromatic Compounds—Recent Advances

“…Wu and Li proposed another convenient method for preparation of N -sulfonyl- and N -acylpyrroles via the olefin ring-closing metathesis of diallylamines in the presence of Ru-2 combined with in situ oxidative aromatization with atmospheric O 2 and suitable copper catalyst such as Cu(OTf) 2 or CuBr 2 ( Scheme 14 ) [ 36 ]. The reaction was performed via a one-pot tandem RCM/dehydrogenation procedure and afforded N -sulfonyl- and N -acylpyrroles with moderate-to-good yields (45–93%).…”