NNN Palladium(II)Pincer Complex in a Borrowing Hydrogen Process: Alkylation of Indoles

Recently, an azine NNN–Pd(II) nonpalindromic pincer complex is generated, and its application in acceptorless dehydrogenative coupling is explored. This article establishes the application of the same pincer complex in the borrowing hydrogen process (BHP). Herein, the selective synthesis of C3 alkylated indoles (CAIs) is reported. Remarkably, this catalyst enables the synthesis of bis(indolyl)methanes (BIMs) by tuning the reaction conditions using the same substrates. The control experiments and quantum chemical analysis suggest that C3 functionalization of indole involves BHP. The formation of BIMs is an additional advantage.