The direct C3 alkylation of indoles and oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C-H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed this borane-catalyzed strategy in an alkylation-ring opening cascade.
The direct C3 alkylation of indoles and n class="Chemical">oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C-H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed this borane-catalyzed strategy in an alkylation-ring opening cascade.
Authors: Alexander F G Maier; Sebastian Tussing; Tobias Schneider; Ulrich Flörke; Zheng-Wang Qu; Stefan Grimme; Jan Paradies Journal: Angew Chem Int Ed Engl Date: 2016-09-05 Impact factor: 15.336
Authors: Guo-Qiang Chen; Gerald Kehr; Constantin G Daniliuc; Markus Bursch; Stefan Grimme; Gerhard Erker Journal: Chemistry Date: 2017-03-15 Impact factor: 5.236