Undirected, Selective Csp2-H Alkynylation of Five-membered Heteroarenes

Abstract

: The functionalization of Csp2-H bond of heteroarene with an alkyne represents one of the most attractive procedures for the late-stage functionalization of the aromatic core due to the structural characteristics and synthetic versatility given by a triple carbon-carbon bond. The aim of this review is to cover the most significant results reported in the literature regarding the synthesis of alkynyl-substituted five-membered heteroarenes by selective direct Csp2-H alkynylation with 1-haloalkynes and analogs, or by cross-dehydrogenative alkynylation (CDA) with terminal alkynes, without making use of directing groups.

Cyclization Reactions of Non-Conjugate Ynones with Propargyl Amine in the Presence of a Catalyst

“…Alkynes allow the synthesis of molecules of different modifications with a wide variety of reactions such as oxidation (16), reduction (17), and nucleophilic addition (18,19). The presence of propargyl pyrrole compounds in structures such as dopamine 4 receptor agonist (20), fungicide, hepatitis C agent, as shown in Figure 1, increases the interest in new pyrrolic propargyl derivatives and in recent years, the production of metal-catalyzed alkylated pyrrolic systems has attracted a lot of attention (21,22). In the literature, generally, pyrrolic propargyl systems have been synthesized either by removing the NH proton with a base or by binding to the N-protected pyrrolic system at the propargyl ortho and/or meta position (23)(24)(25)(26).…”