Iridium-Catalyzed Selective Hydrogenation of 3-Hydroxypyridinium Salts: A Facile Synthesis of Piperidin-3-ones

Abstract

The selective hydrogenation of 3-hydroxypyridinium salts has been achieved using a homogeneous iridium catalyst, providing a direct access to 2- and 4-substituted piperidin-3-one derivatives with high yields, which are important organic synthetic intermediates and the prevalent structural motifs in pharmaceutical agents. Mild reaction conditions, high chemoselectivity, and easy scalability make this reaction highly practical for the synthesis of piperidin-3-ones.

Semi‐Rational Engineering of Toluene Dioxygenase from Pseudomonas putida F1 towards Oxyfunctionalization of Bicyclic Aromatics

“…13 C‐NMR (DMSO‐d6, 125.76 MHz) δ=151.48, 144.38, 140.19, 137.99, 128.79, 127.68, 123.49, 123.31 ppm. Results were in agreement with literature [38] …”

Synthesis of 6-Substituted Piperidin-3-ones via Rh(II)-Catalyzed Transannulation of N-Sulfonyl-1,2,3-triazoles with Electron-Rich Aromatic Nucleophiles

“…Recently, Zhou et al reported an iridium-catalyzed hydrogenation of 3-hydroxypyridinium salts, but this reaction is restricted to the formation of 6- H -piperidin-3-ones (eq 2 in Figure ). Moreover, to the best of our knowledge, the synthesis of piperidin-3-ones bearing quaternary carbons are still unexplored. In this context, the search for a step-economical and efficient system to generate structural diversity of piperidin-3-ones is of great value.…”

Regioselective Radical Arylation of 3-Hydroxypyridines

“…R f = 0.5 (5:1 chloroform/diethyl ether) [UV]; mp = 228 °C; IR (NaCl, cm −1 ) ν; 2417,1574,1510,1460,1358,1280,1221,1181,1156,1118,1078,835,797,761; 1 H NMR (600 MHz, (CD 3 ) 2 SO) δ 10.21 (s, 1H), 8.14 (dd, J = 4.5, J = 1.4 Hz, 1H), 8.08 (dd, J = 9.1 Hz, J HF = 5.8 Hz, 2H), 7.33 (dd, J = 8.2 Hz, J = 1.5 Hz, 1H), 7.24 (t, J HF = 9.0 Hz, J = 9.0 Hz, 2H), 7.20 (dd, J = 8.2, J = 4.5 Hz, 1H); 13 C NMR (151 MHz, (CD 3 ) 2 SO) δ 161.7 (d, J CF = 244.9 Hz), 151.3, 143.1, 140.1, 134.3 (d, J CF = 3.0 Hz), 130.7 (d, J CF = 8.2 Hz), 123.6, 123.5, 114.4 13 C NMR data are in agreement with those previously reported. 29 2-(4-Bromophenyl)pyridin-3-ol (3c). Compound 3c was prepared according to GP1 using 4-bromophenyldiazonium chloride (2c).…”

“…The melting point obtained is in agreement with the value previously reported. 29 N-(4-(3-Hydroxypyridin-2-yl)phenyl)acetamide (3n). Compound 3n was prepared according to GP1 using 4-acetamidobenzenediazonium chloride (2n).…”