Palladium-Catalyzed C-H Arylation and Azetidination of Pentacyclic Triterpenoids.

ABSTRACT: Synthetic protocols for site-selective palladium-catalyzed C-H arylation and azetidination of pentacyclic triterpenoids have been developed. Betulin, oleanolic, and ursolic acids were converted into primary amines C(28)-NH₂ that were further transformed into the corresponding picolinamides. The latter was found to be a suitable directing group for triterpenoid C-(sp ³)-H (het)-arylation with iodo-(het)-arenes in the presence of Pd-(OAc)₂/CuBr₂/CsOAc system. C-(sp ³)-H (het)-arylation provided yields from 29 to 83%, and the C(22)/C(16) selectivity from 9:1 in the lupane (betulin) series to 19:1 in the oleane and ursane series. The highest isolated yields of C-(sp ³)-H arylated products were achieved with

SUBMITTER: Kroskins V 

PROVIDER: S-EPMC12242664 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature