Dual-Reagent Catalysis within Ir−Sn Domain:  Highly Selective Alkylation of Arenes and Heteroarenes with Aromatic Aldehydes

Abstract

Reactions of arenes and heteroarenes with aromatic aldehydes proceeded smoothly in the presence of a catalytic combination of [Ir(COD)Cl]2-SnCl4 to afford the corresponding triarylmethane derivatives (TRAMs) in high yields. This 100% TRAM selective transformation is clean and eliminates the use of acid systems.

A new practical synthesis of triaryl and trisindolylmethanes under solvent-free reaction conditions

“…GC-MS spectra were recorded with an AT5973N mass selective detector connected to an AT6890N GC cross-linked methyl silicone capillary column. 1 H NMR and 13 C NMR spectra were recorded in CDCl 3 with a Bruker Avance 200 spectrometer at 200 MHz and 50 MHz, respectively; chemical shifts are given in ppm relative to CDCl 3 . TLC were performed on Fluka silica gel TLCPET foils GF 254, 2-25 µm, layer thickness 0.2 mm, medium pore diameter 60 A˚.…”

“…A dual-reagent catalytic combination of [Ir(COD)Cl] 2 -SnCl 4 has also been reported to catalyse the Friedel-Crafts alkylation of arenes and heteroarenes; a complexation/interaction of the carbonyl functionality at the tin center has been suggested as a plausible mechanism. 13 Mineral Brønsted acids (such as HF, H 2 SO 4 , H 3 PO 4 ) have been predominantly used as the catalysts for a very long time. The detailed mechanism of the reaction was investigated in-depth by Olah and coworkers, by running the reaction in various superacidic systems (triflic acid, Magic acid, and so on).…”

Ir/Sn dual-reagent catalysis towards highly selective alkylation of arenes and heteroarenes with benzyl alcohols

“…[22][23] Subsequently, the concept has been extended towards the activation of aldehydes, and ethers. [24][25] Extensive kinetic and spectroscopic studies also led to meaningful insights from which we could propose a guide towards electronic tuning of the catalyst efficiency. 26 In this article, we present a comprehensive account from our detailed investigations on the Ir/Sn dualreagent catalysed aromatic alkylation reactions with benzyl alcohols.…”

Unsymmetrically Substituted Leuco-Triarylmethane Molecules Formed from the Reaction of a Fischer's Base and α,β-Unsaturated Iminium Salts via a Michael-Type Reaction

“…Many research groups [12][13][14] have examined the structural modification of LTAM molecules. We previously reported the synthesis and characterization of the Fisher's base (FB) analogs of LTAM molecules such as symmetrically substituted LTAM, (2Z, 2'E)-2,2'-(2-phenylpropane-1,3-diylidene)-bis(1,3,3-trimethylindoline) derivatives and unsymmetric LTAM (Un-LTAM), (2E, 2'E)-2,2'-{(E)-4-phenylpent-2-ene-1,5-diylidene}bis(1,3,3-trimethylindoline) molecules.…”