Combining Gold and Palladium Catalysis: One‐Pot Access to Pentasubstituted Arenes from Furan–Yne and En–Diyne Substrates

Abstract

A series of furan-yne systems was transformed into the corresponding tetrasubstituted annelated phenol derivatives that bear one bromo group. The two-step procedure consisted of a phenol synthesis and a subsequent electrophilic bromination with N-bromosuccinimide (NBS). The reactions can be performed in a one-pot procedure with the same precatalyst. The halogenation reaction is highly selective only in the presence of the gold catalyst. En-diyne substrates were also suitable starting materials; then the pentasubstituted aromatic core showed a completely different substitution pattern for the phenolic products. Furthermore, a one-pot protocol that consisted of a gold-catalyzed phenol synthesis, a gold-catalyzed halogenation reaction, and a palladium-catalyzed Suzuki coupling was established. The overall efficiency of this procedure was excellent and the substrate scope of the reaction was broad.

From Furan–Yne Systems to para-Benzoquinone Derivatives: Gold-Catalyzed Cyclization and Oxidation, and Further Reduction by Sodium Dithionate

“…According to GP 4, 6d (1.42 g, 4.0 mmol), K 2 CO 3 (1.65 g, 12.0 mmol), and propargyl bromide (1.08 g, 10.0 mmol, 80% solution in toluene) in acetone (10 mL) furnished 1d as a white solid after purification by column chromatography (eluent: PE/EtOAc 9:1); yield: 1.41 g (91%, 3.6 mmol); mp 99-100 °C (Lit. 14 All spectral data are in accordance with previous reports. 14…”

Recent Advances in Phthalan and Coumaran Chemistry

“…Scheme shows the general transformation of furans 62 into phthalans 63 . Typical reaction conditions include the use of a gold‐based catalyst and a chlorine‐containing solvent, such as CHCl 3 or CH 2 Cl 2 , at room temperature.…”

Direct synthesis of benzo[a]carbazoles by palladium-catalyzed domino reactions: synthesis and photophysical properties of diverse benzo[a]carbazoles

“…In modern organic chemistry, both tandem reactions and C-H functionalization are considered as efficient tools for the synthesis of complex molecules in terms of atom economy. As part of our ongoing research program on the development of efficient methods in organic synthesis and on the preparation of heterocyclic compounds [41][42][43][44][45][46], to develop a more atom economical and direct …”