Practical synthesis of indoles and benzofurans in water using a heterogeneous bimetallic catalyst

Abstract

SummaryThis paper describes the preparation of indoles, azaindoles and benzofurans in pure water by using a new heterogeneous Pd–Cu/C catalyst through a cascade Sonogashira alkynylation–cyclization sequence. Details of the optimization studies and the substrate scope are discussed. This procedure allows the preparation of heterocycles with good yields and is tolerant to a wide variety of functional groups.

Characterization of a Poly‐4‐Vinylpyridine‐Supported CuPd Bimetallic Catalyst for Sonogashira Coupling Reactions

“…Recently, the presence of Cu in CuPd NPs proved to significantly enhance the catalytic performances of Pd catalysts in carbon–carbon coupling reactions (e.g. Suzuki–Miyaura and Sonogashira reactions) allowing the development of new CuPd catalysts that require also a reduced amount of precious Pd metal …”

Synthesis of Bioactive Five- and Six-Membered Heterocycles Catalyzed by Heterogeneous Supported Metals

“…Recently Felpin et al [72] developed a bimetallic Pd-Cu heterogeneous catalyst supported on active charcoal and used it to synthesize benzofurans by the same protocol of Sonogashira alkynylationcyclization sequence (Scheme 53). Recently Felpin et al [72] developed a bimetallic Pd-Cu heterogeneous catalyst supported on active charcoal and used it to synthesize benzofurans by the same protocol of Sonogashira alkynylationcyclization sequence (Scheme 53).…”

Development of new methods in modern selective organic synthesis: preparation of functionalized molecules with atomic precision

“…561 In this case, Cu plays a dual role, being the catalyst for the alkylation step and the Lewis acid in the cyclization step (Scheme 133).…”