Suzuki–Miyaura Coupling of Aryl Iodides, Bromides, and Chlorides Catalyzed by Bis(thiazole) Pincer Palladium Complexes

Abstract

Bis(thiazole) pincer palladium complexes showed efficient catalytic activity for the Suzuki-Miyaura coupling of aryl halides, allowing the synthesis of biaryls with very high turnover numbers and turnover frequencies. The complexes were successfully applied in the scalable and green synthesis of the key intermediates of bioactive LUF5771 and its analogues.

Iodine‐Promoted Semmler–Wolff Reactions: Step‐Economic Access to meta‐Substituted Primary Anilines via Aromatization

“…By the use of this route, heavy‐metal reagents and protective groups were not utilized, and the requirements of rigorous reaction conditions and special or expensive reagents were totally avoided in each step. The avoidance of the use of heavy‐metal reagents are beneficial to the pharmaceutical manufacturers, since the concentrations of residual metals may be required at the ppm level by government regulations in the active pharmaceutical ingredients (API) while the process to remove residual metals is costly …”

Copper(II)‐Catalyzed Aromatization Followed by Bromination of Cyclohexenones Leading to Phenols and Bromophenols

“…2‐Bromo‐3,5‐biphenylphenol (1a): 13 Yield 126.8 mg (65 %). 1 H NMR (400 MHz, CDCl 3 ): δ = 7.59–7.57 (m, 2 H), 7.44–7.39 (m, 7 H), 7.36–7.35 (m, 1 H), 7.27 (d, J = 2.0 Hz, 1 H), 7.14 (d, J = 2.0 Hz, 1 H), 5.85 (br., 1 H, OH) ppm.…”

[2,6-Bis(5-ethoxy-1,3-oxazol-2-yl)-4-methoxyphenyl-κ3N,C1,N′]bromidopalladium(II)

“…For studies on the chemistry of bis(oxazole) pincer palladium complexes, see: Luo et al (2007Luo et al ( , 2011; Xu et al (2011). For structures of related bis(azole) pincer palladium complexes, see: Ghorai et al (2012); Luo et al (2012).…”

“…Considerable attention has recently been devoted to pincer-Pd complexes due to their catalytic abilities (Ghorai et al, 2012;van Koten & Gebbink, 2011;Moreno et al, 2010;Selander & Szabó, 2011). We are interested in the NCN type of pincer-Pd complexes (Luo et al, 2007(Luo et al, , 2011(Luo et al, , 2012Xu et al, 2011) as a variety of nonphosphine pincer catalytic system, that contains two nitrogen atoms as donating sites in the coordination sphere (Hao et al, 2010;Young et al, 2011) The title compound was conveniently synthesized from the reaction of Pd(dba) 2 (dba = dibenzylideneacetone) with 1bromo-2,6-bis(5-ethoxyoxazol-2-yl)-4-methoxy benzene in dry benzene under reflux in an argon atmosphere. As a result, the title compound was isolated with 84% yield.…”