KO^tBu Mediated Synthesis of Phenanthridinones and Dibenzoazepinones

Abstract

Synthesis of substituted phenanthridinones and dibenzoazepinones has been realized from 2-halo-benzamides in the presence of potassium tert-butoxide and a catalytic amount of 1,10-phenanthroline or AIBN. This new carbon-carbon bond forming reaction gives direct access to various biaryl lactams containing six- and seven-membered rings chemoselectively. Carbon-carbon coupling seems to proceed by the generation of a radical in the amide ring which leads to C-H arylation of aniline.

Transition‐Metal‐Free Synthesis of N‐Substituted Phenanthridinones and Spiro‐isoindolinones: C(sp2)−N and C(sp2)−O Coupling through Radical Pathway

“…Nonetheless, the synthesis of N‐alky‐substituted phenanthridinones and double functionalization yielding phenanthridinone core along with an additional functionality which can be used for late stage transformation utilizing economical reagents are desirable. In continuation of our work on TM‐free C−C, C−N, and C−O coupling reactions and synthesis of heterocycles, herein, we disclose a TM and base‐free synthesis of phenanthridinones via oxidative C−N coupling of C−H and N−H bond utilizing iodine, DTBP and succinimide in 1,2‐dichloroethane at 130 °C. Interestingly, spiro‐ iso indolinones also constructed serendipitously from the same substrates using PIDA oxidant instead of DTBP by phenyl ring de‐aromatization involving intramolecular C−N and intermolecular C−O coupling reactions.…”

A New Method for the Synthesis of Phenanthridine Compounds

“…161～162 ℃; 1 H NMR (400 MHz, CDCl 3 ) δ: 8.39 (d, J＝8.6 Hz, 1H), 7.94 (t, J＝12.6 Hz, 3H), 7.65 有机化学 研究论文 (d,J＝8.0 Hz,2H),7.49 (dd,J＝15.2,8.4 Hz, 3H), 7.16 (d,J＝9.0 Hz,1H), 4.03 (s, 3H), 2.58 (s, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ: 161. 3, 159.4, 144.3, 139.2, 138.5, 135.7, 134.7, 131.1, 130.3, 129.8, 128.5, 128.3, 121.7, 121.3, 119.7, 116.9, 102.7, 55.5, 21.5;IR (KBr) ν: 3058, 2920, 2860, 1610, 1558, 1490, 1452, 1361 (d, J＝7.6 Hz, 2H), 7.45 (d, J＝8.4 Hz, 1H), 7.34 (d,J＝6.8 Hz,3H), 2.60 (s, 3H), 2.57 (s, 3H), 2.46 (s, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ: 161.1, 144.1, 140.6, 138.6, 138.3, 137.2, 133.6, 129.7, 129.6, 128.9, 128.7, 128.2, 123.1, 121.6, 121.5, 121.1, 22.1, 21.5, 21.3;IR (KBr) ν: 3026, 2916, 2857, 1616, 1560, 1492, 1450, 1361 3-甲基菲啶-6(5H)-酮(4a) [17] : 白色固体, 产率 73%. m.p.＞250 ℃; 1 H NMR (400 MHz, DMSO-d 6 ) δ: 11.63 (s, 1H), 8.45 (d,J＝8.0 Hz,1H),8.34～8.30 (m,1H),8.26 (d,J＝8.0 Hz, 1H), 7.89～7.77 (m, 1H), 7.61 (t, J＝7.6 Hz, 1H), 7.09 (d,J＝8.0 Hz,1H), 2.39 (s, 3H); 13 C NMR (101 MHz, DMSO) δ: 160.…”

A Radical Process towards the Development of Transition‐Metal‐Free Aromatic CarbonCarbon Bond‐Forming Reactions

“…A transition metal-free protocol was found to be useful for the synthesis of biologically active phenanthridinones and related lactams from 2-halobenzamide (Scheme 24). [36] In the presence of KOtBu and a catalytic amount of either 1,10-phenanthroline or azoisobutylonitrile (AIBN), the intramolecular direct arylation was found to proceed smoothly. The scope of aryl halides was extended to even aryl chlorides, although moderate product yields were afforded.…”

“…Intramolecular direct arylation to synthesize phenanthridinones. [36] www.chemeurj.org chloride intramolecularly (Scheme 25). [38] In particular, only 10 mol % of catalyst was found to be sufficient to catalyze this reaction.…”