Palladium‐Catalyzed Cross‐Coupling Reactions of 4‐Tosyl‐2(5H)‐furanone with Boronic Acids: A Facile and Efficient Route to Generate 4‐Substituted 2(5H)‐Furanones.

Abstract

Generate 4-Substituted 2(5H)-Furanones. -The title reaction gives a range of furanones from both electronrich and electron-poor boronic acids and 4-tosylfuranone (I), which is prepared by simple mixing of tetronic acid, TosCl and Et3N. However, the coupling of 3-phenyl-4-tosyl-2(5H)-furanone with two aryl boronic acids fails. Compared with its corresponding triflate, (I) is superior in terms of stability, synthetic reagent costs, and easy preparation. -(WU*, J.; ZHU, Q.; WANG, L.; FATHI, R.; YANG, Z.; J.

Transition Metal-Free Intermolecular C(sp2)–H Direct Amination of Furanones via a Redox Pathway

“…11 These 2-furanone structural motifs have also been incorporated into a wide variety of therapeutically interesting drug candidates that include Penicillic acid, Basidalin, Eucilat, and L-784512. 12 Compared with 3-or 5-substituted 2furanones, the synthesis of 4-substituted 2-furanones has been particularly problematic, 13 and transition metal-catalyzed coupling methodologies are employed in the overwhelming majority of synthetic reports. 14 However, there has hitherto been no report on the synthesis of 4-N-substituted 2-furanones via direct C−H amination to the best of our knowledge.…”

“…45−7.38 (m, 2H), 7.38−7.33 (m, 1H), 7.31−7.26 (m, 3H), 4.67 (d, J = 6.6 Hz, 2H), 4.31 (q, J = 7.1 Hz, 2H), 1.68 (s, 6H), 1.35 (t, J = 7.1 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl 3 ) δ 179. 3, 167.2, 166.6, 135.8, 129.3, 128.5, 126.8, 86.1, 79.3, 60.3, 48.2, 25.2, 14.4 Ethyl 4-((2,3-Dimethylbenzyl)amino)-5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylate (3b).…”

“…1 H NMR (400 MHz, CDCl 3 ) δ 8.86 (s, 1H), 7.17 (d, J = 7.1 Hz, 1H), 7.13 (t, J = 7.5 Hz, 1H), 7.06 (d, J = 7.2 Hz, 1H), 4.63 (d, J = 6.1 Hz, 2H), 4.29 (q, J = 7.1 Hz, 2H), 2.32 (s, 3H), 2.25 (s, 3H), 1.69 (s, 6H), 1.33 (t, J = 7.1 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl 3 ) δ 179. 3, 167.2, 166.6, 137.8, 134.1, 133.6, 130.4, 126.3, 125.5, 86.0, 79.3, 60.3, 47.0, 24.9, 20.5, 14.9, 14.4.…”

“…1 H NMR (400 MHz, CDCl 3 ) δ 9.13 (s, 1H), 7.36 (t, J = 7.8 Hz, 1H), 7.21 (d, J = 7.2 Hz, 1H), 7.04−6.90 (m, 2H), 4.63 (d, J = 6.5 Hz, 2H), 4.32 (q, J = 7.1 Hz, 2H), 3.92 (s, 3H), 1.71 (s, 6H), 1.37 (t, J = 7.1 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl 3 ) δ 179.0, 167.4, 166.6, 157.1, 130.0, 128.4, 124.0, 121.0, 110.8, 85.6, 79.2, 60.1, 55.4, 44.5, 25.1, 14.5. HRMS (ESI) m/z calcd for C 17 H 22 NO 5 [M + H] + 320.1493, found 320.1495.…”

Vitamin B12: An efficient type catalyst for the one-pot synthesis of 3,4,5-trisubstituted furan-2(5 H )-ones and N -aryl-3-aminodihydropyrrol-2-one-4-carboxylates

“…5H-Furan-2-onederivatives exhibit many pharmacological and biological activities including antifungal, antibacterial, antioxidants, anti-inflammatory, anti-microbial and anti-cancer agents [15][16][17][18][19]. Due to this wide range of abundance and applicability, various approaches toward substituted butenolides have been developed, which involve the use of organo-lithium [20], boronic acids [21,22], transition-metal catalysts such as Pd(OAc) 2 [23], Ru [24], Cu(II) [25], AuCl [26], and secondary amines [27]. However, many of these methods involve the use of expensive catalysts and hazardous reagents in stoichiometric amounts.…”