Arylation of arylamines

Preparation of the very active catalyst (X-Phos)2Pd from (MeCN)2PdCl2 starts by ligand exchange with TMEDA, which is followed by reaction with MeLi at 0°, and further treatment with X-Phos and 2-(o-chloropheny l)ethylamine, prior to warming to room temperature to split off indoline. The precatalyst (before elimination of indoline) can he used directly for A-arylation of arylamines. 

A construction of the carbazole framework involving copper(ll)-catalyzed aryla-mine arylation and palladium(ll)-mediated oxidative cyclization has been reported by Menendez et al. (Scheme 41) [190, 191]. The diarylamines 95 were obtained by copper(ll) acetate-catalyzed N-arylation of arylamines 31 with phe-nyllead triacetate (183) using Barton s conditions [192]. Subsequent oxidative cyclization using palladium(ll) acetate under microwave irradiation afforded the carbazoles 32. This procedure was applied to the synthesis of murrayafoline A (188) [190]. 

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