Synthesis of 3-aryl-1-phosphinoimidazo[1,5-a]pyridine ligands for use in Suzuki–Miyaura cross-coupling reactions

Abstract

3-Aryl-1-phosphinoimidazo[1,5-a]pyridine ligands were synthesized from 2-aminomethylpyridine as the initial substrate via two complementary routes and were evaluated in the Suzuki–Miyaura cross-coupling reactions.

Visible Light-Driven, Gold(I)-Catalyzed Preparation of Symmetrical (Hetero)biaryls by Homocoupling of Arylazo Sulfones

“…Purification was carried out by silica gel chromatographic column (eluant: cyclohexane/ethyl acetate 3:7) to afford 74.1 mg of 41 (94% yield, slightly yellow solid, mp 64–66 °C). Spectroscopic data were in accordance with the literature data …”

“…Spectroscopic data were in accordance with the literature data. 57 1 H NMR (300 MHz, CDCl 3 ) δ 8.86 (d, J = 2.4 Hz, 2H), 8.67 (dd, J = 4.9, 1.6 Hz, 2H), 7.91 (dt, J = 7.9, 2.0 Hz, 2H), 7.44 (dd, J = 7.9, 4.8 Hz, 2H). 13 C{ 1 H} NMR (75 MHz, CDCl 3 ) δ 149.3, 148.1, 134.8, 133.7, 124.0.…”

Luminescent Imidazo[1,5‐a]pyridine Scaffold: Synthetic Heterocyclization Strategies‐Overview and Promising Applications

“…Very recently, two complementary synthetic routes have been reported to obtain 1‐phosphine‐ impy ligands for use in Suzuki‐Miyaura cross‐coupling reactions (see Scheme 15). [80] This is the first synthetic procedure reported to collect a 1‐phosphine‐ impy nucleus in high yield, the obtained products represent a powerful intermediate to design variously substituted luminescent molecules.…”

“…[79] Very recently, two complementary synthetic routes have been reported to obtain 1-phosphine-impy ligands for use in Suzuki-Miyaura cross-coupling reactions (see Scheme 15). [80] This is the first synthetic procedure reported to collect a 1phosphine-impy nucleus in high yield, the obtained products Scheme 11. Recent reported synthetic approaches to obtain impy nucleus (reaction yields: first approach from 62 to 98%, second approach from 97 to 99% depending on the tested substituents R (e. g. phenyl, pyridyl, methyl) and R' (e. g. pyridyl, methyl and naphtyl); third approach from 30 to 80%, depending on the tested substituents R (e. g. phenyl, tolyl) and R' (e. g. COOCH 2 CH 3 , COOC(CH 3 ) 3 ).…”

Suzuki‐Miyaura and Buchwald‐Hartwig Cross‐Coupling Reactions Utilizing a Set of Complementary Imidazopyridine Monophosphine Ligands

“…To the best of our knowledge, no one has investigated the catalytic activity of cross‐coupling reactions based on imidazopyridines as heterocyclic ligand types. Recently, our group disclosed the preparation of monophosphine ligands such as 3‐aryl‐2‐phosphinoimidazo[1,2‐ a ]pyridine 1 [32] and 3‐aryl‐1‐phosphinoimidazo[1,5‐ a ]pyridine 2 [33] and showcased them in selected brief cross‐coupling reactions (Figure 2). These two ligands possess hemilable N ‐chelating group providing weak coordinating property, offering potential for dynamic interaction for catalyst longevity, has high potential of ligand tunability with steric and electronic properties by the incorporation of different aryl rings, and finally has tunable P‐donor group providing electron richness.…”