ABSTRACT
Ynamides are versatile substrates in organic synthesis, the electron-rich character of the polarized ‘r-system makes them ideal substrates for regio-, chemo- and stereoselective transformations. Moreover, ynamides possess good affinity for Lewis and Brøinsted acids and they easily form highly reactive keteniminium ions upon reaction with an electrophile. Pericyclic reactions of ynamides have attracted a lot of interest from the synthetic community and are now well-established tools [1,2]. Depending on the substitution, the presence (and nature) of a catalyst and the reaction conditions, ynamides can be used as 2π- electrons partner (C≡C), 4π-electrons (for aromatic-substituted ynamides) or can even act as a three atoms system sharing π-electrons (N-C≡C). The present chapter, by no mean exhaustive, gathers pericyclic reactions of ynamides up to 2022 and is organized by classes of cycloaddition: [2+1] cycloadditions will be discussed first followed by [2+2], [3+2], [4+1], [4+2], [4+3], [5+1], [5+2] and, finally, [2+2+2] reactions.
