Synthesis of New Functionally Substituted 9-Azabicyclo[4.2.1]nona-2,4,7-trienes by Cobalt(I)-Catalyzed [6π + 2π]-Cycloaddition of N-Carbocholesteroxyazepine to Alkynes

Gulnara N Kadikova; Vladimir A D'yakonov; Usein M Dzhemilev

doi:10.3390/molecules26102932

Synthesis of New Functionally Substituted 9-Azabicyclo[4.2.1]nona-2,4,7-trienes by Cobalt(I)-Catalyzed [6π + 2π]-Cycloaddition of N-Carbocholesteroxyazepine to Alkynes

Molecules. 2021 May 14;26(10):2932. doi: 10.3390/molecules26102932.

Authors

Gulnara N Kadikova¹, Vladimir A D'yakonov¹, Usein M Dzhemilev¹

Affiliation

¹ Laboratory of Catalytic Synthesis, Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, 450075 Ufa, Russia.

Abstract

Catalytic [6π + 2π]-cycloaddition of N-carbocholesteroxyazepine with functionally substituted terminal alkynes and 1,4-butynediol was performed for the first time under the action of the Co(acac)₂(dppe)/Zn/ZnI₂ three-component catalytic system. The reaction gave previously undescribed but promising 9-azabicyclo[4.2.1]nona-2,4,7-trienes (in 79-95% yields), covalently bound to a natural metabolite, cholesterol. The structure of the synthesized azabicycles was confirmed by analysis of one- and two-dimensional (¹H, ¹³C, DEPT ¹³C, COSY, NOESY, HSQC, HMBC) NMR spectra.

Keywords: 9-azabicyclo[4.2.1]nona-2,4,7-trienes; N-carbocholesteroxyazepine; alkynes; cobalt(II) acetylacetonate; cycloaddition.

Grants and funding

19-73-10116/Russian Science Foundation