“…While many powerful reactions have been developed for the synthesis of indoles, [4] synthetic methods allowing efficient construction of 2aminoindoles remained limited. [5][6][7][8][9][10][11] Listed in Scheme 1 are some of the recently developed methodologies including 1) Pd-catalyzed Buchwald -Hartwig N-arylation of 2-haloindoles with anilines (Scheme 1,a); [12,13] 2) Pd-catalyzed heteroannulation of Nalkynyl-2-haloanilides with amines (Scheme 1,b); [14] 3) Pd-catalyzed coupling of ynamides and o-iodoanilines (Scheme 1,c); [15] 4) Pd-catalyzed domino N-arylation followed by base-promoted cyclization (Scheme 1,d); [16] 5) copper-catalyzed reaction of substituted N-(2halophenyl)-2,2,2-trifluoroacetamides with alkyl 2-cyanoacetate or malononitrile (Scheme 1,e); [17] 6) goldcatalyzed intermolecular reaction of azides with ynamides (Scheme 1,f). [18,19] In spite of these significant achievements, the development of practical and cost-effective methods are still highly demanding.…”