@article {45528,
	title = {Nickel-catalyzed straightforward and regioselective C-H alkenylation of indoles with alkenyl bromides: scope and mechanistic aspect},
	journal = {ACS Catalysis},
	volume = {9},
	year = {2019},
	month = {JAN},
	pages = {431-441},
	type = {Article},
	abstract = {<p>Nickel-catalyzed regioselective C-H bond alkenylation of indoles and related heteroarenes with alkenyl bromides is accomplished under relatively mild conditions. This method allows the straightforward synthesis of C-2 alkenylated indoles employing an air-stable and well-defined nickel catalyst, (bpy)NiBr2, providing a solution to the limitations associated with hydroindolation and oxidative alkenylation. The reaction conceded the coupling of indole derivatives with various alkenyl bromides, such as aromatic and heteroaromatics, alpha- and beta-substituted as well as exo- and endo-cyclic alkenyl compounds. An extensive mechanistic investigation, including controlled study, reactivity experiments, kinetics and labeling studies, and EPR and XPS analyses, highlights that the alkenylation proceeds through a single-electron transfer process comprising an odd-electron oxidative addition of alkenyl bromide. Furthermore, the alkenylation operates via a probable Ni(I)/Ni(III) pathway involving the rate-limiting C-H nickelation of indole.</p>},
	keywords = {alkenylation, C-H activation, indoles, Mechanism, Nickel, single-electron transfer},
	issn = {2155-5435},
	doi = {10.1021/acscatal.8b04267},
	author = {Jagtap, Rahul A. and Vinod, C. P. and Punji, Benudhar}
}
@article {47412,
	title = {Nickel-catalyzed C-H bond functionalization of azoles and indoles},
	journal = {Chemical Record},
	volume = {21},
	year = {2021},
	month = {DEC},
	pages = {3573-3588},
	type = {Article},
	abstract = {<p>Direct C-H functionalization of privileged and biologically relevant azoles and indoles represents an important chemical transformation in molecular science. Despite significant progress in the palladium-catalyzed regioselective C-H functionalization of azoles and indoles, the use of abundant and less expensive nickel catalyst is underdeveloped. In the recent past, the nickel-catalyzed regioselective C-H alkylation, arylation, alkenylation and alkynylation of azoles and indoles have been substantially explored, which can be applied to the complex organic molecule synthesis. In this Account, we summarize the developments in nickel-catalyzed regioselective functionalization of azoles and indoles with a considerable focus on the reaction mechanism.</p>},
	keywords = {azoles, C-C Bond formation, C-H functionalization, indoles, Nickel},
	issn = {1527-8999},
	doi = {10.1002/tcr.202100113, Early Access Date = JUN 2021},
	author = {Jagtap, Rahul A. and Punji, Benudhar}
}
@article {47638,
	title = {Ni(II)-catalyzed intramolecular C-H/C-H oxidative coupling: an efficient route to functionalized cycloindolones and indenoindolones},
	journal = {ACS Catalysis},
	volume = {11},
	year = {2021},
	month = {OCT },
	pages = {12384-12393},
	type = {Article},
	abstract = {Nickel(II)-catalyzed intramolecular C(sp(2))-H/C(sp(3))-H and C(sp(2))-H/C(sp(2))-H oxidative couplings in indoles are achieved via chelation assistance. These reactions provide access to biologically relevant five- and six-membered substituted cyclopentaindolones, carbazolones, and indenoindolones in high yields and good chemoselectivity employing an air-stable and defined nickel catalyst, (bpy)Ni(OAc)(2). The oxidative cyclizations proceeded either through a six-membered or an unconventional seven-membered nickelacycle. An extensive mechanistic investigation by experiments and theoretical calculations revealed a facile indole{\textquoteright}s C(2)-H nickelation and a rate-limiting reductive elimination process. This intramolecular oxidative cyclization operates via a probable Ni(II)/Ni(III) pathway involving single-electron oxidation of nickel without the participation of a carbon-based radical.},
	keywords = {C-H activation, cycloindolones, indenoindolones, indoles, Mechanism, Nickel, oxidative coupling},
	issn = {2155-5435},
	doi = {10.1021/acscatal.1c03314},
	author = {Ankade, Shidheshwar B. and Samal, Pragnya Paramita and Soni, Vineeta and Gonnade, Rajesh G. and Krishnamurty, Sailaja and Punji, Benudhar}
}
