A transition metal-free one-pot, three-steps protocol combining N-alkynylindoles, n-butyllithium, elemental selenium, and an electrophile source was developed to allow the synthesis of 3-(organoselanyl) selenazolo indoles. Substrate scope was studied by varying the structure of Nalkynylindoles and the electrophile source. This sequential reaction proceeded selectively through an initial intramolecular 5-endo-dig mode with two new carbon−selenium bonds formation in a one-pot procedure. The reaction conditions were also compatible with elemental sulfur and tellurium, which led to construct 3-(alkylthio) thiazolo indoles and 3-(alkyltelluro) tellurazolo indoles, respectively. In addition, it was also demonstrated that a series of dichalcogenides derived from chalcogenazoloindoles ring could be easily prepared via oxidation of chalcogenolate anion in contact with air.
Iron-promoted cyclization of 1-benzyl-2-alkynylbenzenes with diorganyl diselenides led to the synthesiso f9 -(organoselanyl)-5H-benzo [7]annulenes whereby the mutual action between diorganyl diselenides andiron(III) chloride in a0 .5:1.0 molr atio was essential in order to achieve the maximal yields of the products.T he cyclization reaction tolerated av ariety of functional groups,s uch as trifluoromethyl, chloro,f luoroa nd methoxy,i nb otht he 1-benzyl-2-alkynylbenzenes and the diorganyl diselenides, giving the seven-membered heterocyclic products exclusively via a7-endo-dig cyclization process.
Base-Mediated Intramolecular Cyclization of (2-Propargyl Ether) Arylimines: An Approach to 3-Amino-benzofurans. -An arylamine bearing an alkyl alkyne instead of an aryl alkyne functionality does not afford the desired product. -(GAI, R.; PROCHNOW, T.; BACK, D. F.; ZENI*, G.; Tetrahedron 70 (2014) 24, 3751-3756, http://dx.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.