Cyclization and Cycloisomerization of π-Tethered Ynamides: An Expedient Synthetic Method to Construct Carbo- and Heterocycles

Abstract

Stable ynamides are used for the development of novel synthetic transformations and the construction of unusual carbo/heterocycles. The intramolecular cyclization of π-tethered alkene/alkyne/allene-ynamides is studied extensively for the fabrication of a wide range of molecular scaffolds for various applications. The ketene-acetal/aminal generated in situ from π-tethered ynamides participates in intramolecular cyclization/cycloisomerization processes to yield N-bearing fused heterocycles. This account summarizes the scientific merits and the advances made in cyclization and cycloisomerization strategies for stable π-tethered alkene/alkyne/allene-ynamides.1 Introduction2 π-Tethered Ynamides3 Alkene-Tethered Ynamides4 Alkyne-Tethered Ynamides5 Allene-Tethered Ynamides6 Concluding Remarks