Cyclization of Diaryl(hetaryl)alkynes under Selenobromination Conditions: Regioselectivity and Mechanistic Studies

European Journal of Organic Chemistry 2015
E. Paegle, Sergejs Beļakovs, M. Petrova, E. Liepiņš, P. Arsenyan

The cyclization of substituted diaryl(hetaryl)alkynes with in-situ-prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials. The reactions can be performed in air without the use of moisture-sensitive reagents, dry solvents, or an inert atmosphere. Mechanistic studies confirmed a regioselective anti 1,2-addition in the selenobromination step, and a subsequent electrophilic substitution in the aromatic ring to complete the cyclization.

Keywords
Cyclization, Selenobromination Conditions, Alkynes
DOI
10.1002/ejoc.201500431
Hyperlink
http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201500431/abstract

Paegle, E., Beļakovs, S., Petrova, M., Liepiņš, E., Arsenyan, P. Cyclization of Diaryl(hetaryl)alkynes under Selenobromination Conditions: Regioselectivity and Mechanistic Studies. European Journal of Organic Chemistry, 2015, Iss.20, pp.4389-4399. e-ISSN 1099-0690. Available from: doi:10.1002/ejoc.201500431

Publication language
English (en)