Synthesis of (E)‐3‐Alkylideneindolin‐2‐ones by an Iron‐Catalyzed Aerobic Oxidative Condensation of Csp³–H Bonds of Oxindoles and Benzylamines

Abstract

A novel synthetic route for the construction of (E)‐3‐alkylideneindolin‐2‐ones through iron‐catalyzed aerobic oxidative condensation of oxindoles with benzylamines has been developed. This oxidative reaction involves a sequence of C–H activation, amine self‐condensation, nucleophilic addition, and C–C double bond formation. The synthetic importance of this protocol has been demonstrated by preparing tyrosine kinase inhibitors, anticonvulsant and antitumor agents, and other valuable 3‐alkylideneindolin‐2‐one derivatives. Key intermediates are isolated and a plausible mechanistic pathway for the reaction has been discussed.

Pd-catalyzed one-pot approach for installation of 9-aminoacridines via Buchwald-Hartwig amination and cycloaromatization

“…Furthermore, the utility of this methodology was applied to the synthesis of 9-amino-6-chloro-2-methoxy acridine (ACMA, Scheme 1), which is an important scaffold in drug compounds such as mepacrine (antimalarial) and quinpramine (antiprion). [43][44] Besides, many of the synthesized 9-aminoacridine compounds, viz., 2-methoxy-9-acridinamine (4a), 3-methyl-9-acridinamine (5b) and 4-methyl-9-acridinamine (5e) are used as precursors for the synthesis of bioactive molecules. [45][46][47] To test the feasibility of the Buchwald-Hartwig amination for different halogen partners, we performed the reactions with 2-chlorobenzonitrile, 2-iodobenzonitrile, and 2-iodo-4-methylbenzonitrile under the optimized catalytic conditions (Scheme 2).…”