A New Synthesis of Indenones

Divergent Synthesis of α-Aroyloxy Ketones and Indenones: A Controlled Domino Radical Reaction for Di- and Trifunctionalization of Alkynes

“…Calcd for C 22 H 16 O: C,89.16;H,5.44. Found: C,89.48;H,3-diphenyl-1H-inden-1-one (4b): 22 orange solid; yield 75% (22 mg); R f = 0.58 (silica gel, hexane/EtOAc 95:5); 1 H NMR (500 MHz, CDCl 3 ) δ 2.64 (s, 3H), 6.99 (d,J = 7.2 Hz,1H),7.08 (d,J = 7.8 Hz,1H),6H),5H); 13 C{ 1 H} NMR (125 MHz, CDCl 3 ) δ 17.4,119.2,127.0,127.6,128.0,128.6,128.7,129.0,130.0,130.9,132.2,132.4,132.6,132.9,138.0,145.7,154.3,197.6. Anal.…”

“…5-Methoxy-2,3-diphenyl-1H-inden-1-one (4d): 24 orange solid; yield 59% (19 mg); R f = 0.44 (silica gel, hexane/EtOAc 90:10); 1 H NMR (500 MHz, CDCl 3 ) δ 3.85 (s, 3H), 6.69 (dd, J = 7.9, 2.2 Hz, 1H), 6.72 (d,J = 2.2 Hz,1H),5H),2H),3H),7.57 (d,J = 7.9 Hz, 1H); 13 C{ 1 H} NMR (125 MHz, CDCl 3 ) δ 55. 8, 110.3, 110.5, 123.5, 124.9, 127.7, 128.0, 128.5, 128.8, 129.1, 130.0, 130.9, 132.7, 133.9, 147.9, 153.2, 164.4, 195.1; EI-MS m/z 312 (M •+ , 100), 281(30), 268 (27), 252 (17), 239 (54), 135 (33), 120 (22). Anal.…”

“…2,naphthalen-1-one (4f): 25 orange solid; yield 42% (14 mg); R f = 0.42 (silica gel, hexane/EtOAc 95:5); 1 H NMR (500 MHz, DMSO-d 6 ) δ 7. 13−7.19 (m, 4H), 7.36−7.44 (m, 3H) 8, 123.1, 125.6, 126.3, 126.5, 127.0, 127.2, 128.4, 129.0, 129.1, 129.4, 129.8, 130.0, 130.8, 131.1, 133.1, 133.8, 134.8, 146.3, 155.2, 196.2; EI-MS m/z 332 (M •+ , 100), 316 (19), 303 (48), 282 (21), 255 (21), 155 (21), 141 (22), 127 (19). Anal.…”

“…Found: C,70.15;H,3.76. 7-Chloro-2,3-diphenyl-1H-inden-1-one (4j). 22 orange solid; yield 72% (23 mg); R f = 0.39 (silica gel, hexane/EtOAc 95:5); 1 H NMR (500 MHz, CDCl 3 ) δ 6.85 (d, J = 7.5 Hz, 1H), 10H),7.55 (d,J = 8.3 Hz,1H), 7.62 (d, J = 7.2 Hz, 1H); 13 C{ 1 H} NMR (125 MHz,CDCl 3 ) δ 121.4,123.0,127.3,128.0,128.1,128.9,129.3,129.9,130.0,130.2,130.6,132.7,133.0,133.7,133.8,196.3; EI-MS m/z 316 (M •+ , 74), 281 (100), 252 (62), 176 (10), 126 (9). Anal.…”

A Metal‐Free Oxidative Carboannulation Approach towards Synthesis of 2,3‐Diarylindenones and Its Regioisomers

“…Undoubtedly, direct annulation of an aryl aldehyde from commercially available starting material with an internal alkyne is most atom‐economical and straight forward route leading to indenone scaffold. Our experimental studies were inspired by an old report of a direct annulations of an aldehyde and alkyne leading to indenone in presence of tert‐butyl peroxide with extremely poor yield and very limited substrate scope . Inspired by all these work, herein we report a much improved radical oxidative annulation pathway between aromatic aldehydes and internal alkyne to construct 2,3‐diaryl indenone moiety using PIDA as an oxidant and DTBP as an additive in DMA solvent at 100 o C for 24 h (scheme 1 , eq 5 ).…”