Oxidative Aminoaziridination of 2‐Vinylfuran Derivatives as an Approach to Hexa‐2,5‐diene‐1,4‐dione Monohydrazones

Abstract

The oxidative addition of N-aminophthalimide to substituted2-vinylfurans provides monophthaloylhydrazones of (2Z)-hexa-2,5-diene-1,4-dione derivativesi nstead of 2-furylaziridines by proceeding through an aziridination of the endocyclic furan C=Cb ond followed by ar egio-and stereoselective rearrangement of the bicyclic intermediate. The formation of stable aziridines can then occur through the aziridination of the (E)-C=Cb ondo ft hese phthaloylhydrazones. Detailed structure elucidations and mechanistic considerations are provided.

Ru(II)-Catalyzed Asymmetric Transfer Hydrogenation of Chalcones in Water: Application to the Enantioselective Synthesis of Flavans BW683C and Tephrowatsin E

“…13 C { 1 H} NMR (126 MHz, CDCl 3 , Me 4 Si) δ 188.1, 163.4, 151.8, 144.7, 131.1, 130.7, 129.9, 119.2, 115.8, 113.8, 112.5, 55.4. Spectroscopic data were consistent with those reported in the literature …”

Oxidative aminoaziridination: past, present, and future

“…The above mentioned spontaneous isomerization of aziridinated furans into monophthaloylhydrazones of (2Z)-alk-2-en-1,4-diones (Scheme 11) 38 and also the transformation of azoaziridines into 1,2,3-triazoles with the aromatization in the last step As mentioned in the latter case, the alkynyl substituent and R 1 group in the aziridine have to be cis-oriented for a productive rearrangement. 32 Oxidative aminoaziridination of tertiary and secondary allylic alcohols with API/PIDA in the presence of acidic silica resulted in good yields of β-phthaloylhydrazinoketones, products of the The oxidative aminoaziridination is used nowadays as a reliable tool for stereospecific and often stereoselective conversion of easily available unsaturated starting compounds to a variety of Naminoaziridine derivatives which are able to undergo numerous intra-and intermolecular transformations.…”

A Metal-Free Domino Process for Regioselective Synthesis of 1,2,4-Trisubstituted Pyrroles: Application toward the Formal Synthesis of Ningalin B

“…Following protocol A, using ( E )-2-methyl-5-(2-nitrovinyl)­furan (0.38 g, 2.5 mmol), 2m was obtained as pale yellow solid (0.52 g, 91% yield); mp 69–70 °C. IR (neat): ν max 3054, 2986, 1714, 1606, 1422, 1326, 1264, 1165, 1123, 895 cm –1 ; 1 H NMR (400 MHz, CDCl 3 ):δ 8.51 (s, 1H), 7.35 (d, J = 3.2 Hz, 1H), 6.00 (d, J = 3.2 Hz, 1H), 2.42 (s, 3H); 13 C­{ 1 H} NMR (100 MHz, CDCl 3 ): δ 159.3, 145.2, 125.0, 122.9, 122.4, 110.7, 14.2.…”

“…(Z)-2-(2-Bromo-2-nitrovinyl)-5-methylfuran (2m). Following protocol A, 39 using (E)-2-methyl-5-(2-nitrovinyl)furan 43 (0.38 g, 2.5 mmol), 2m was obtained as pale yellow solid (0.52 g, 91% yield); mp 69−70 °C. IR (neat): ν max 3054,2986,1714,1606,1422,1326,1264,1165,1123,895 (3) General Procedure for Synthesis of 1,2,4-Trisubstituted Pyrroles.…”