Potassium [1-(tert-butoxycarbonyl)-1H-indol-2-yl]trifluoroborate (1) was used in Suzuki-type coupling reactions. First, the best coupling conditions were assessed using bromobenzene as the electrophile. Then, 1 was successfully coupled with various aryl and hetaryl bromides. Finally, the reactivity of 1 towards coupling partners other than bromide derivatives was evaluated. Suzuki coupling - organotrifluoroborates
Photoredox C(2)-Arylation of Indole- and Tryptophan-Containing Biomolecules
作者:Bruno M. da S. Santos、Fernanda G. Finelli、David R. Spring
DOI:10.1021/acs.orglett.4c01019
日期:2024.5.17
methodology for photoredox arylation of an indole scaffold using aryldiazonium salts under mild and metal-free conditions. Our approach enables the regioselective and chemoselective introduction of several aryl groups to the C(2) position of indoles and tryptophan, even in competition with other amino acids. This approach extends to the late-stage functionalization of peptides and lysozyme, heralding
Palladium-Catalyzed Cross-Coupling of Five-Membered Heterocyclic Silanolates
作者:Scott E. Denmark、John D. Baird、Christopher S. Regens
DOI:10.1021/jo7023784
日期:2008.2.1
The preparation of pi-rich 2-aryl heterocycles by palladium-catalyzed cross-coupling of sodium heteroarylsilanolates with aryl iodides, bromides, and chlorides is described. The cross-coupling process was developed through extensive optimization of the following key variables: (1) identification of stable, isolable alkali metal silanolates, (2) identification of conditions for preformation and isolation of silanolate salts, (3) judicious choice in the palladium catalyst/ligand combination, and (4) selection of the protecting group on the nitrogen of indole. It was found that the alkali metal silanolates, either isolated or formed in situ, offered a significant rate enhancement and broader substrate scope over the use of silanols activated by Bronsted bases such as NaOt-Bu. In addition, the optimized conditions for the cross-coupling of 2-indolylsilanolates were readily applied to the cross-coupling of 2-pyrrolyl-, 2-furyl-, and 2-thienylsilanolates.