Microwave-assisted three-component domino reaction: Synthesis of indolodiazepinotriazoles

• Rajesh K. Arigela,
• Sudhir K. Sharma,
• Brijesh Kumar and
• Bijoy Kundu

Beilstein J. Org. Chem. 2013, 9, 401–405, doi:10.3762/bjoc.9.41

• Abstract A microwave-assisted three-component protocol involving N-1 alkylation of 2-alkynylindoles with epichlorohydrin, ring opening of the epoxide with sodium azide, and an intramolecular Huisgen azide–internal alkyne 1,3-dipolar cycloaddition domino sequence has been described. The efficacy of the

• methodology has been demonstrated by treating various 2-alkynylindoles (aromatic/aliphatic) with epichlorohydrin and sodium azide furnishing annulated tetracyclic indolodiazepinotriazoles in satisfactory yields. Keywords: 2-alkynylindoles; azides; 1,3-dipolar cycloaddition; domino reaction

• azide–internal alkyne 1,3-dipolar cycloaddition reaction. Once the reaction conditions for the three-component format had been optimized, several 2-alkynylindoles bearing different functional groups were treated with epichlorohydrin and sodium azide in order to establish the scope and limitation of the

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• step. Xi and co-workers developed an elegant one-pot synthesis of 2-alkynylindoles 64 involving o-bromo-(2,2-dibromovinyl)benzenes 63, arylamines and terminal alkynes as starting partners [36]. It should be noted that the three components are present at the same time in the reaction system and the best

• coupling leading to a mono-alkynylated product, followed by an intermolecular Buchwald–Hartwig amination and a subsequent intramolecular amination. This Pd-catalyzed tandem coupling reaction allows the preparation of a variety of 2-alkynylindoles 64 (Scheme 28). An elegant three-component process based on