1,2-Silyl Shift-Induced Heterocyclization of Propargyl Silanes: Synthesis of Five-Membered Heterocycles Containing a Functionalized Olefin Side Chain
The Journal of Organic Chemistry 2023
Rasma Kroņkalne, Rūdolfs Beļaunieks, Artjoms Ubaidullajevs, Anatolijs Mišņovs, Māris Turks

Propargyl silanes with a terminal alkyne moiety undergo a 1,2-silyl shift when activated with electrophiles such as H+, Br+, I+, and PhSe+. A method was developed to trap 1,3-transposed electrophilic centers with various internal O-, N-, and S-nucleophiles in a 5-exo manner. This synthetic procedure provided five-membered heterocycles containing a trisubstituted olefin side chain. The scope of the method includes access to tetrahydrofuran, γ-butyrolactone, 2-isooxazoline, pyrrolidine, and thiolane derivatives in yields ranging from 25 to 85% (23 examples in total). Reactions with TsNBr2 ensured complete (E)-selectivity of the newly formed olefins. Further functionalization of the obtained 1-trialkylsilyl-2-bromovinyl side chain was demonstrated by double-bond geometry-preserving electrophilic substitution and cross-coupling reactions that provided heterocycles with a trisubstituted vinyl moiety.


Keywords
Propargyl Silane, 1,2-Silyl Shift, Heterocyclization
DOI
10.1021/acs.joc.3c01481
Hyperlink
https://pubs.acs.org/doi/abs/10.1021/acs.joc.3c01481

Kroņkalne, R., Beļaunieks, R., Ubaidullajevs, A., Mišņovs, A., Turks, M. 1,2-Silyl Shift-Induced Heterocyclization of Propargyl Silanes: Synthesis of Five-Membered Heterocycles Containing a Functionalized Olefin Side Chain. The Journal of Organic Chemistry, 2023, Vol. 88, No. 19, pp.13857-13870. ISSN 0022-3263. e-ISSN 1520-6904. Available from: doi:10.1021/acs.joc.3c01481

Publication language
English (en)
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