A novel and metal-free I2-mediated intramolecular C2 amidation of indoles under mild reaction conditions is developed. This methodology affords various indole fused tetracyclic compounds, such as benzo[4,5]imidazo[1,2-a]indoles by intramolecular C2 amidation of N-aryl substituted indoles. This C2 sulfonamidative cyclization also offers convenient access to indolo[2,3-b]indoles and dihydroindolo[2,3-b]quinoline from C3 aryl substituted indoles in good to excellent yields. Indolo[2,3-b]quinolines are also synthesized by the domino cyclization-detosylation-aromatization reaction sequence.

A metal- and base-free protocol for intramolecular cross-coupling of C(sp)-H and N-H bonds using N-iodosuccinimide (NIS) has been demonstrated. This environmentally benign approach furnishes a series of substituted indolo[1,2-a]quinazolinones from the suitably fabricated indoles via C-N bond forming cyclization in 28-82% yield. A plausible mechanism is proposed for this cyclization based on the results of a control experiment. This methodology requires no additional metal catalyst, oxidant, or base. Furthermore, the synthetic utility of the protocol is demonstrated by performing a gram scale reaction.

Biologically important bisindolylmethanes are synthesized in a domino fashion by using an iron(II) chloride-(±)-1,1′-binaphthyl-2,2′-diamine [FeCl 2 -(±)-BINAM] complex as the catalyst. This method proceeds via oxidation of a primary alcohol into the corresponding aldehyde followed by nucleophilic addition of an indole in the presence of the catalyst. A reaction intermediate is synthesized separately and converted into the bisindolylmethane product under the same reaction conditions as support for the proposed mechanism.

An efficient, green and first catalytic process hasb een developed for the direct synthesiso f amides from readilya vailablep etroleum by-products (methylarenes) anda mines using an iron catalyst. In this newc atalytic reaction, the methylg roup of the methylarene is oxidized to the corresponding aldehyde through non-directed C (sp 3 ) À Ho xidation followed by its oxidative amidation with N-chloroamine,y ielding the carboxylic amide.O xidation with an iron catalyst, tert-butyl hydroperoxide (TBHP) as sole oxidant, the synthesiso fa mides under mild reaction conditions and the utilizationo fm ethylarenes as starting material maket his methodology novel and environmentally benign.

Iron(II) Chloride-1,1'-Binaphthyl-2,2'-diamine (FeCl 2-BINAM) Complex Catalyzed Domino Synthesis of Bisindolylmethanes from Indoles and Primary Alcohols. -(BADIGENCHALA, S.; GANAPATHY, D.; DAS, A.; SINGH, R.; SEKAR*, G.; Synthesis 46 (2014) 1, 101-109, http://dx.doi.org/10.1055/s-0033-1340052 ; Dep. Chem., Indian Inst. Technol., Chennai 600 036, India; Eng.) -M. Tismer 25-127