Synthesis of Bis(3‐indolyl)methanes Mediated by Potassium tert‐Butoxide

Abstract

The indole moiety is an important N-heterocycle found in natural products, and a key structural component of many value-added chemicals including pharmaceuticals. In particular, bis(3-indolyl)methanes (BIMs) are an important subgroup of indoles, composed of two indole units. Herein, we report the development of a simple method to access BIMs derivatives in yields of up to 77 % by exploiting a tBuOK-mediated coupling reaction of indoles and benzyl alcohols.

Exploring Thermomyces lanuginosus Lipase (TLL)‐PdNPs Nanohybrid as Suitable Catalyst for One‐pot Synthesis of Bis(3‐indolyl)phenylmethane

“…13 C NMR (101 MHz, CDCl 3 ): δ=144.1, 136.7, 128.8, 128.34, 127.1, 126.2, 123.7, 122.0, 120.0, 119.7, 119.3, 111.1, 40.3. NMR is in accordance with previous reported [30] …”

“…1 H NMR (400 MHz, CDCl 3 ): δ=8.02 (s, 2H), 7.70 (s, 2H), 7.44 (d, J =8.5 Hz, 2H), 7.35–7.25 (m, 5H), 7.16 (d, J= 8.5 Hz, 2H), 6.61 (s, 2H), 5.77 (s, 1H); 13 C NMR (101 MHz, CDCl 3 ): δ=143.22, 135.94, 130.60, 129.63, 128.68, 128.67, 128.56, 126.66, 124.52, 118.96, 113.26, 83.07, 39.94. NMR is in accordance with previous reported [30] …”

“…Products 3, 6, 9,11 and 13 were purified by silica gel chromatography, Hexane/AcOEt (6 : 1) with gradient; PTLC, Hexane/AcOEt (6 : 1) with gradient and product 15 with Hexane/AcOEt (4 : 1) with gradient; PTLC, Hexane/AcOEt (4 : 1) with gradient. [30] 3,3'-(Phenylmethylene)bis(1H-indole) (3). NMR is in accordance with previous reported.…”

“…NMR is in accordance with previous reported. [30] 3,3'-(Phenylmethylene)bis(5-iodo-1H-indole) (6). 1…”

Divergence in CH alkylation of indoles under Mn catalysis

“…A similar reaction was performed with two equivalents of radical scavengers (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), and this experiment also shows that the reaction did not proceed through a single-electron path (Scheme 3d). It is worth mentioning that Marques and coworkers 20 proposed a radial coupling mechanism for the formation of BIM using a stoichiometric amount of K t OBu under mediated conditions. To clarify if metal-mediated dehydrogenation is involved or not, we conducted kinetic studies on the reaction using different concentrations of NNN–Mn( ii ) [ Mn-5 ].…”