030

Title:

Intermolecular [3+2] Annulation of N-Cyclopropylanilines and Styrene Via Electrochemistry-Assisted Carbon-Carbon Bond Formation

Discipline: Chemistry

Presenter:

QI WANG

Abstract:

Recent advances in visible-light triggered photocatalysis have significantly promoted organic synthesis development. One of the examples in this regard is the visible-light-promoted [3+2] cycloaddition of alkenes with cyclopropylamine, catalyzed by ruthenium (Ru) complex Ru(bpz)3(PF6)2,. Nevertheless, one drawback of the visible-light-mediated reactions is the use of expensive photocatalysts. In this paper, we present an alternative way for intermolecular [3+2] cycloaddition of N-cyclopropyl-3, 5-dimethylaniline (CPDA) and styrene by electrosynthesis, without using the otherwise needed photocatalyst. For small-scale test of the reaction viability, electro-oxidation of both CPDA and styrene in a thin-layer electrochemical flow cell, equipped with a magic diamond working electrode, reference electrode, and titanium auxiliary electrode, was online monitored by a mass spectrometer for formation of reaction product during electrolysis. A potentiostat was used to control voltage for electro-oxidation. To scale up the electrosynthesis, more substrates were added into a vial and reticulated vitreous carbon (RVC) and platinum (Pt) were used as anode and cathode individually and inserted into the glass vial for electrolysis. A separate power supply was used to apply the potential to electrodes. The sample was collected after an overnight reaction and analyzed by both electrospray ionization mass spectrometry (ESI-MS) and NMR.

Author(s):

Qi Wang, Qile Wang, Nan Zheng, Richard N. Zare, Yuexiang Zhang, and Hao Chen

Funding Acknowledgements:

This work was supported by NSF (CHE-1915878).