Synthesis of Tridentate [1,2,4] Triazinyl-Pyridin-2-yl Indole Lewis Basic Complexants via Pd-Catalyzed Suzuki-Miyaura Cross-Coupling

Zachary Z Gulledge; Mariah L Tedder; Kyle R Lyons; Jesse D Carrick

doi:10.1021/acsomega.9b02891

Synthesis of Tridentate [1,2,4] Triazinyl-Pyridin-2-yl Indole Lewis Basic Complexants via Pd-Catalyzed Suzuki-Miyaura Cross-Coupling

ACS Omega. 2019 Oct 29;4(20):18855-18866. doi: 10.1021/acsomega.9b02891. eCollection 2019 Nov 12.

Authors

Zachary Z Gulledge¹, Mariah L Tedder¹, Kyle R Lyons¹, Jesse D Carrick¹

Affiliation

¹ Department of Chemistry, Tennessee Technological University, 55 University Drive, Cookeville, Tennessee 38505-0001, United States.

Abstract

Full closure of the nuclear fuel cycle is predicated, in part, on defining efficient separations processes for the effective speciation of the neutron-absorbing lanthanides from the minor actinides post-PUREX. Pursuant to the aforementioned, a class of tridentate, Lewis basic procomplexants have been prepared leveraging a Pd-catalyzed Suzuki-Miyaura cross-coupling between 6-bromo-[1,2,4]-triazinylpyridine derivatives and various protected indole-boronic acids to afford functionalized 2-[6-(5,6-diphenyl-[1,2,4]triazin-3-yl)-pyridin-2-yl]-1H-indoles. A highly active catalyst/ligand system with low loadings was employed rapidly affording 26 examples in yields as high as 85%. Method optimization, substrate and indole scope, comparative analysis between coupling reagents, and a scale-up experiment are reported.