Hydrogen transfer indole alkylation with

Chloroform added dropwise at room temp, to a stirred mixture of N-methyl-aniline, aq. 50%-NaOH, benzyltriethylammonium chloride, and, optionally, methylene chloride, and stirring continued 1-2 hrs. -> N-formyl-N-methylaniline. Y 76%. F. e. s. J. Grafe, I. Frohlidi, and M. Muhlstadt, Z. Chem. 14, 434 (1974) s. a. M. Makosza and A. Kacprowicz, Rocz. Chem. 49, 1627 (1975) (Eng) C. A. 84, 43265 N-alkylation with alkyl halides, ibid. 49, 1203 (Eng) C. A. 84, 30793 cf. R. Brehme, Synthesis 1976, 113 with tetrabutylammonium hydrogen sulfate as phase transfer catalyst, indole derivs., cf. A. Barco et al., Synthesis 1976, 124. 

Other indole syntheses of this type include the iridium-catalyzed hydrogen transfer of amine-substituted benzylic alcohols (130L3876), the intramolecular dehydrative coupling of tertiary amines with ketones (13OL6018), and the sequential alkylation/cyclization/isomerization of 3-(o-tri luoroacetamidoaryl)-l-propargylic esters (13T9494). 

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