Er(OTf)3-catalyzed approach to 3-alkenylindoles through regioselective addition of ynamides and indoles

Silver‐catalyzed Regioselective Synthesis of N‐aryl‐1H‐pyrazolyl‐substituted Benzenesulfonamides from Ynamides and Pyrazoles

“…[20] Erbium catalyzed synthesis of 3-alkenylindoles were developed by Wei and co-workers [Scheme 1 equation iv]. [21] Robert et al, reported the nitrogen atom of indoles can be functionalized with ynamides through base catalysis [Scheme 1 equation v]. [22] Cui and their research gruop reported that N-alkynyl pyrazoles reacted with pyrazoles in the presence of base to give mixture of alpha and beta substituted dipyrazolyl derivatives [Scheme 1 equation vi].…”

Unexpected stereoselective CuBr2-catalyzed cascade reaction of 2-ethynylanilines with silylynamides: facile and atom-economical access to N-vinylsilylindoles

“…10 For the vinylation of indoles with ynamides, in most cases, the reaction takes place exclusively at the C3 position due to its innate nucleophilic nature (Scheme 1a, left). 11 In 2014, an unprecedented base-promoted N -vinylation of indoles with terminal ynamides was reported by Dodd and co-workers, providing a convenient access to N -vinylindoles (Scheme 1a, right). 12 Despite these advances, current methodologies toward N -vinylindoles mainly focus on the direct N–H bond functionalization of indoles, whereas the more challenging one-step construction of indole skeletons together with installation of vinyl moieties at the N1 position is scarcely explored.…”

A gold-catalyzed cyclization/nucleophilic addition reaction of o-alkynylanilines with ynamides: stereoselective synthesis of 3-vinylindoles

“…8 The Wang group reported the erbium-catalyzed cis -hydroacylation of ynamides with indoles for the synthesis of 3-vinylindoles with the Z -configuration (Scheme 1b). 9 Alternatively, the cyclization of acyclic starting materials provided a step-economical strategy for the preparation of substituted indole derivatives. 10 Thus in this study, acyclic o -alkynylanilines and ynamides were treated in the presence of a gold catalyst, which would provide a stepwise and economical strategy for the direct synthesis of 3-vinylindoles (Scheme 1c).…”