Without a trace: The first meta‐selective direct CH arylation that uses iodoarenes as coupling partners is reported (see scheme, EWG=electron‐withdrawing group). This process utilizes carboxylic acid units as temporary directing groups that are cleaved during the reaction, leaving no trace in the resulting biaryl products.

An efficient, one-pot reductive alkylation of indoles with N-protected aminoethyl acetals in the presence of TES/TFA is reported. It represents the first general method for the direct synthesis of tryptamine derivatives from indoles and nitrogen-functionalized acetals. This convergent and versatile approach employs safe and inexpensive reagents, proceeds under mild conditions, and tolerates several functional groups. The new procedure was efficiently applied to a gram-scale synthesis of both luzindole, a reference MT2-selective melatonin receptor antagonist, and melatonin.

A new, robust, and reliable method has been developed for the selective reductive N-alkylation of primary and secondary aromatic amines with some functionalized acetals using TFA/Et(3)SiH as a reagent combination. A variety of unsymmetrically substituted ethylenediamines can be synthesized in a one-pot procedure in excellent yields at room temperature. This new procedure offers significant advantages over previous synthetic approaches, including brevity, mild reaction conditions, excellent yields, and high functional group tolerance.

A practical and efficient synthesis of 3-substituted hexahydropyrrolo[2,3-b]indole is described. The addition/cyclization of 3-substituted indoles with alpha,beta-dehydroamino esters in the presence of a Lewis acid provides hexahydropyrrolo[2,3-b]indole adducts in good yields and stereoselectivities. This approach has been applied to the concise synthesis of esermethole employing an appropriately substituted indole and an N-acyl dehydroamino ester.

Spurlos: Bei der ersten meta‐selektiven direkten C‐H‐Arylierung mit Iodarenen als Kupplungspartnern (siehe Schema, EWG=elektronenziehende Gruppe) werden Carbonsäureeinheiten als temporäre Steuergruppen genutzt, die während der Reaktion abgespalten werden, ohne eine Spur in den gebildeten Biarylprodukten zu hinterlassen.