02156nas a2200217   4500008004100000022001400041245012800055210006900183260000900252490000700261520138300268653001501651653002301666653001201689653001101701653002701712100002801739700002301767700002001790856012801810       2024                        eng d  a1434-193X00aNickel-catalyzed branch-selective C-H alkylation of indoles and azoles with alkenes: an additive- and solvent-free approach0 aNickelcatalyzed branchselective CH alkylation of indoles and azo  cJUL 0 v273 a<p>
	The development of sustainable protocols for the synthesis of alkylated heteroarenes is crucial owing to their widespread existence in medicinally relevant and bioactive natural products. Herein, we describe an efficient, additive- and solvent-free approach for the regioselective C-H alkylation of indoles and azoles with alkenes using a nickel catalyst, which proceeds through a chelation-assistance strategy. The reaction exclusively provided branched alkylated products with the compatibility of alkyl, alkoxy, fluoro, trifluoromethyl, alkene, cyano, ester, and carbonyl groups. This protocol is applicable to other heteroarenes, such as imidazoles and benzimidazoles, providing the desired alkylated products with exclusive Markovnikov selectivity. The synthetic utility and scale-up of the reaction are demonstrated, and the protocol is in concord with the principles of green chemistry. Alkylation proceeds through facile and reversible C-H nickelation and alkene insertion processes, presumably involving rate-limiting reductive elimination. A straightforward nickel-catalyzed protocol for the C-H alkylation of indoles and azoles is disclosed that proceeds under additive- and solvent-free conditions. The reaction utilizes readily available alkenes as alkylating partners and delivers Markovnikov products with tolerance of sensitive functionalities. image</p>
10aAlkylation10abranch selectivity10aindoles10aNickel10asolvent-free synthesis1 aAnkade, Shidheshwar, B.1 aBanerjee, Shuvajit1 aPunji, Benudhar  uhttps://library.ncl.res.in/content/nickel-catalyzed-branch-selective-c-h-alkylation-indoles-and-azoles-alkenes-additive-and