The Synthesis of Aromatic Heterocycles from Propargylic Compounds

Abstract

It is well known that the aromatic heterocyclic compounds are the most ubiquitous motifs and are found in many natural products and pharmaceuticals that exhibit remarkable biological activities. Significant effort continues to be given to the development of new methods for their construction. Although a number of methods have been established to construct these compounds, the development of novel methods that allow the facile assembly of substituted heterocycles from readily available starting materials remains an important objective. In recent years, propargylic compounds that contain many reactive centers have attracted a lot of attention for their various transformations. Chemists have conducted a detailed investigation of their cyclization with nucleophiles. The cyclization of propargylic compounds with a variety of nucleophiles is a very efficient method for producing furans, pyrroles, thiazoles, indoles, imidazoles, indolizines, oxazoles, pyridines, quinolines, thiophenes, and so on. In this review, we highlight the substantial progress that has been made in this area between 2000 and mid-2012, and give examples of the reactions of propargylic compounds with a variety of substrates to produce heterocycles.

Recent approaches for the synthesis of pyridines and (iso)quinolines using propargylic Alcohols

“…In recent years, many review articles have appeared describing the general reactivity of propargylic alcohols for the construction of various cyclic systems, including heterocyles. [11][12][13][14][15][16][17][18][19][20][21][22][23][24] To the best of our knowledge, no focused reviews have appeared on the synthesis of six-membered nitrogen basedheterocyclic compounds by employing the propargylic alcohols as one of the key reactants. Thus, in this review article, we aimed to summarize various approaches to N-heterocyclic compounds from propargylic alcohols, and we have limited our focus to the pyridines, quinolines, and isoquinolines.…”

“…In recent years, many review articles have appeared describing the general reactivity of propargylic alcohols for the construction of various cyclic systems, including heterocyles. 11–24…”

Recent Advances in the Synthesis of Thiophene Derivatives by Cyclization of Functionalized Alkynes

“…Metal-catalyzed heterocyclization of functionalized alkynes bearing a suitably placed heteronucleophilic group is a powerful methodology for the regioselective and atom-economical synthesis of substituted heterocycles starting from readily available acyclic substrates (Scheme 1, Y = heteroatom) [31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49]. The generally accepted mechanism for this important transformation involves the electrophilic activation of the triple bond by coordination to the metal center, followed by either exo or endo cyclization (ensuing from intramolecular nucleophilic attack by the –YH group to the coordinated triple bond) and protonolysis (Scheme 1).…”

Synthesis of Thiazolidine‐2‐thiones through a One‐Pot A3‐Coupling–Carbon Disulfide Incorporation Process

“…Propargylic compounds such as propargylic alcohols and propargylamines have recently emerged as useful building blocks and intermediates in heterocyclic chemistry . This is partially attributed to recent progress in the development of efficient catalytic methods for their synthesis.…”