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

Abstract

A catalytic combination of [Ir(COD)Cl] 2 -SnCl 4 efficiently promotes the reactions of arenes and heteroarenes with 1°/2°/3° benzyl alcohols as the alkylating agents to afford the corresponding diarylmethane and triarylmethane derivatives in high yields. The scope and limitation of the reaction with respect to catalyst and substrates variation has been studied in detail.

Highly Mesoporous MoO3 Catalysts for Electrophilic Aromatic Substitution

“…Since product B 2-methyldiphenylmethane (electrophilic substitution product) is more thermodynamically stable and kinetically favorable, this material was observed as the major product. The rate constant for the reaction was calculated to be 2.91, which is quite good as compared to the previously reported literature and considering that our synthesized catalyst procedures are straightforward and economical. ,,− Previously, in the case of iridium- and scandium-based metal–organic framework (MOF), a greater TON has been reported compared to this work (TON = 115). Iridium 42 -based different MOFs give TONs of 530 [{IrCp*Cl2}­2/AgOTf] and 950 [{IrCp*­(Otf)­2}­2/1,3-di- n -butyl-imida-zolylidene, {IrCp*­(OTf)­2}­2/1,3-di- n -methyl-4 methyl imidazole, and {IrCp*­(OTf)­2}­2/1,2-di- n -methyl imidazole], whereas scandium 11 -based MOF gives a TON of 490 {Sc­(OSO2C8F17)­3}.…”

Synthetic methodologies of achiral diarylmethanols, diaryl and triarylmethanes (TRAMs) and medicinal properties of diaryl and triarylmethanes-an overview

“…(48) for the benzylations of the benzylic alcohols having bhydrogens for the preparation of diarylmethanes (Scheme 76). 102,103 The hard main group metal center of the complex activated the hard donor atom while the so transition metal center activated the so donor center such as the p-electron cloud. The authors observed that at room temperature the reaction was sluggish and much of the starting material remains unreacted.…”

Trifluoroacetic Acid-Promoted Friedel-Crafts Aromatic Alkylation with Benzyl Alcohols

“…White solid (mixture from EtOH); Yield 68%; mp 58-64 °C (Lit [38], for 20, mp 85-86 °C; for 21, mp 78 °C); NMR (CDCl 3 ) δ 7.7-7.0 (m, 28H), 4.45 (s, 4H), 3.90 (s, 4H); the latter peaks in a 3:1 ratio; (Lit [39], (for 20) NMR (CDCl 3 ) δ 7.30 (m, 4H), 7.23 (m, 6H), 7.16 (m, 4H), 3.99 (s, 4H); GC also showed two peaks in a ratio of 3:1. The major isomer (20) agreed by comparison with an authentic sample as prepared below.…”

“…4 [10], rare earth (III) (OSO 2 C 8 F 17 ) 3 [14] zeolites [15][16][17], [19,20], 12-tungstophosphoric acid [21], I 2 [22] IrCp* complexes [23], MoO 6 [24], NaHSO 4 /SiO 2 [25], Ph 3 P(OTf) 2 [26], Fe(III)-porphyrin [27] BF 3 -H 2 O [28], Hf 0.5 [TEAPS] PW 12 O 40 [29], choline chloride-(TfOH) 2 [30], and B(C 6 F 5 ) 3 [31]. Our method is eco-friendly as the only by-product is water and the TFA can be recycled.…”

“…To minimize the concentration of TFA, we diluted it with acetic acid (in a ratio of 1:10), but these alkylation conditions of benzene (11) with benzyl alcohol (10) only yielded benzyl acetate, consistent with the enhanced nucleophilicity of acetic acid vis-à-vis TFA. Given the propensity of TFA to promote rearrangements [32,33] in a control experiment we heated 1,4-dbenzylbenzene (20) in TFA for 12 h, but it was recovered unchanged. In the alkylations of toluene (13), biphenyl (12), and naphthalene (22) (Table 1) the expected isomeric mixtures were obtained, and the ratios were estimated by proton NMR integration.…”