Nickel-Catalyzed Reductive 1,2-Dialkynylation of Alkenes Bearing an 8-Aminoquinoline Directing Group

Abstract

An unprecedented nickel-catalyzed reductive 1,2-dialkynylation of alkenes bearing an 8-aminoquinoline directing group has been developed. This method proceeded through a migratory insertion/reductive-coupling process under mild conditions with a wide substrate scope and good functional group tolerance, providing direct access to the synthetically flexible 1,5-diynes. Moreover, the 1,2-dialkynylation products could be further converted to borate-ester- or azide-functionalized 1,5-dienes, ditriazole, β-diyne primary amide, and trisubstituted benzene.

Anti-selective [3+2] (Hetero)annulation of non-conjugated alkenes via directed nucleopalladation

“…Mechanistic studies. In analogy to earlier work [34][35][36][37][38][39][40][41][42][43][44][45][46][47] , we surmised that the reaction may proceed by the general mechanism depicted in Fig. 2c, involving a sequence of alkene coordination, nucleopalladation, intramolecular oxidative addition, and reductive elimination.…”

“…During the past 5 years, our laboratories have developed a variety of transition-metal-catalyzed, three-component directed alkene 1,2-difunctionalization reactions facilitated by the 8aminoquinoline (AQ) auxiliary, a strongly coordinating bidentate directing group. Using this strategy we and others have reported examples of hydrofunctionalization [21][22][23][24][25][26][27][28][29][30][31][32][33] , dicarbofunctionalization [34][35][36][37][38][39] , carboamination 40,41 , and carbo-/aminoboration [42][43][44][45] , among other transformations 46,47 (Fig. 1c).…”

Recent developments in nickel-catalyzed intermolecular dicarbofunctionalization of alkenes

“…28 Very recently, the Lin and Yao groups applied this AQ-directed system toward a reductive 1,2-dialkynylation of non-conjugated alkenes. 29 In 2018, the Zhao group reported a series of 1,2-and 1,3dicarbofunctionalization reactions using a 2-aminopyrimidine directing group derived from allyl amine with C(sp)/C(sp 2 )-X electrophiles and C(sp 2 )-boronic acids as nucleophiles (Fig. 11).…”

Ni-Catalyzed Reductive Difunctionalization of Alkenes

“…This reaction provided an efficient method to access diverse synthetically flexible 1,5-diynes (Scheme 9). 9 In 2019, the Nevado group modified their previous procedure and further developed an intermolecular nondirected reductive dicarbofunctionalization of alkenes (Scheme R 1 = R 3 = H, R 2 = OMe, 78% R 1 = R 3 = H, R 2 = F, 64% R 1 = R 3 = CF 3 , R 2 = H, 46% R 1 = OMe, R 2 = Br, R 3 = H, 69% R 1 = Cl, R 2 = H, R 3 = COOMe, 65% R 2 = R 3 = H, R 1 = OMe, 71% R 2 = R 3 = H, R 1 = CF 3 , 62%…”