1,3-Butadiynamides the Ethynylogous Ynamides: Synthesis, Properties and Applications in Heterocyclic Chemistry

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 11; p. 4564
• Main Authors: Lenko, Illia, Alayrac, Carole, Bożek, Igor, Witulski, Bernhard
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05-06-2023; MDPI
• Series: Recent Developments in the Synthesis and Functionalization of Nitrogen Heterocycles
• Subjects: 1,3-diynamides; Alkynes; annulation reactions; Carbon; Chemical bonds; Chemical reactions; Chemical Sciences; Chemistry; Copper; heterocycles; homogeneous catalysis; Iodine; Molecular orbitals; Molecular structure; Nitrogen; Optoelectronics; Organic chemistry; Review; Silver; Transition metals; ynamides; 1,3-diynamides; indoles; cycloaddition cascade reactions; homogeneous catalysis; heterocycles; alkynes; Hexa-dehydro-Diels–Alder (HDDA) reaction; helical twisted frontier molecular orbitals (Hel-FMO); ynamides; annulation reactions; carbazoles; quinolines; 1-3-diynamides; Hexa-Dehydro-Diels-Alder (HDDA) reaction
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28114564

1,3-butadiynamides-the ethynylogous variants of ynamides-receive considerable attention as precursors of complex molecular scaffolds for organic and heterocyclic chemistry. The synthetic potential of these C4-building blocks reveals itself in sophisticated transition-metal catalyzed annulation reactions and in metal-free or silver-mediated HDDA (Hexa-dehydro-Diels-Alder) cycloadditions. 1,3-Butadiynamides also gain significance as optoelectronic materials and in less explored views on their unique helical twisted frontier molecular orbitals (Hel-FMOs). The present account summarizes different methodologies for the synthesis of 1,3-butadiynamides followed by the description of their molecular structure and electronic properties. Finally, the surprisingly rich chemistry of 1,3-butadiynamides as versatile C4-building blocks in heterocyclic chemistry is reviewed by compiling their exciting reactivity, specificity and opportunities for organic synthesis. Besides chemical transformations and use in synthesis, a focus is set on the mechanistic understanding of the chemistry of 1,3-butadiynamides-suggesting that 1,3-butadiynamides are not just simple alkynes. These ethynylogous variants of ynamides have their own molecular character and chemical reactivity and reflect a new class of remarkably useful compounds.