Trimethylsilyl Iodide as a Multifunctional Agent in the One-Pot Synthesis of 9-(1H-Indol-3-yl)xanthen-4-(9H)-ones from O-Methyl Protected Salicylaldehydes, Indoles, and β-Dicarbonyl Compounds
substitution/cyclization are performed to furnish the target product. The key step in this protocol is the deprotection of the methoxy group by TMSI. Trimethylsilyliodide (TMSI) is introduced as an efficient reagent for the one-pot synthesis of 9-(1H-indol-3-yl)xanthen-4-(9H)-ones using the reaction of 2-methoxybenzaldehydes (as O-methyl protected salicylaldehydes), indoles, and β-dicarbonyl compounds
An efficient and facile protocol has been documented for the synthesis of 4H-chromene and xanthen-1-one derivatives via a three component one pot reaction of salicyladehyde, malononitrile/dimedone and indole utilizing biomimetic catalyst. Affiliation between biomimetic and organocatalyst exhibits a versatile and high catalytic activity emerging to be a sustainable alternative to other catalysts. The significant features of this protocol are compatibility with various types of indole and active-methylene compound, accomplishment of high yields, cleaner reaction condition and avoidance of the use of costly catalysts. Recyclability of beta-cyclodextrin a "biomimetic catalyst" is a significant feature of this protocol.