Heteroarene‐tethered Functionalized Alkyne Metamorphosis

Abstract

Heteroarene-tethered functionalized alkynes are multipotents ynthons in organic chemistry.T his detailed Review described herein offers at horough discussion of the metamorphosis of heteroarene-tethered functionalized alkynes, an area which has earned much attention over the past decade in the straightforward synthesis of architecturally complex heterocyclics caffolds in atom and step economic manner.D epending upon the variety of functionalized al-kynes, this Review is divided into multiple sections. Amongst the vast array of synthetic transformations covered, dearomatizings pirocyclizations and cascades pirocyclization/rearrangementa re of great interest. Synthetic transformations involving the heteroarene-tethered functionalized alkynes with scope, challenges, limitations, mechanism, their application in the total synthesis of natural products and future perceptionsa re surveyed. [a] D. Bag, Prof.

Synthesis of chiral polycyclic N-heterocycles via gold(i)-catalyzed 1,6-enyne cyclization/intramolecular nucleophilic addition

“…In a very ingenious way, it allowed them to synthesize the natural product nakadomarin A. 6 With a general interest in asymmetric gold( i ) catalysis and its application to total synthesis, 7 we intended to develop an enantioselective version of this transformation and the extension to 1,6-enyne substrates substituted with either indoles and dihydropyrroles (Scheme 1c). Furthermore, DFT calculations permitted to better understand the key cyclization step via a spirocyclic intermediate.…”

2,3‐Diodocarbazoles by a Domino Iodocyclization/Iodo‐Translocation of (3‐Iodoindolyl)butynols

“…Our journey started with the study of the reaction of phenyl‐substituted alkynol 1 a as model substrate (Table 1). [10] We explored the reaction of 1 a with several iodinated reagents such as I 2 , NIS, ICl and Ipy 2 BF 4 . The tandem iodocyclization‐iodine translocation was effectively attained through the use of ICl [11] in isopropanol at −15 °C in presence of sodium carbonate.…”

Iodocycloisomerization/Nucleophile Addition Cascade Transformations of 1,2-Alkynediones

“…Alkynes are elementary functionalities in chemistry, and their versatility in the synthesis of numerous chemicals makes them synthons of great consequence . Among the emerging protocols for the intramolecular alkyne functionalization reactions developed in recent years, transformations of heteroarene-tethered functionalized alkynes have attracted considerable attention for atom- and step-economic access of diverse architecturally complex heterocyclic scaffolds of phenomenal material and medicinal applications . Over the past decade, the phenomenon of indole-tethered ynone cycloisomerization has gained considerable recognition and a number of divergent cascade dearomatizing spirocyclization/isomerization reactions in which initial π-activation promotes a nucleophilic dearomatizing spirocyclization involving C-3 of the indole nucleus have been developed (Scheme A) .…”