RESUMO
The use of hydrazinecarboxamides as a new class of carbamoylating agents has been established through the dehydrazinative Minisci reaction of electron-deficient nitrogen heteroarenes. A wide range of electron-deficient nitrogen heteroarenes, including isoquinoline, quinoline, pyridine, phenanthridine, quinoxaline, and phthalazine, underwent copper/acid-catalyzed oxidative carbamoylation with hydrazinecarboxamide hydrochlorides to afford structurally diverse nitrogen-heteroaryl carboxamides as single regioisomers in moderate to excellent yields. The functional group tolerance was substantially demonstrated in the direct carbamoylation of quinine obviating multistep sequences involving protecting groups and prefunctionalization of the heterocycle.
RESUMO
A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1â mol % [Pd(allyl)Cl]2 , 4â mol % (S)-SegPhos, and 10â mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.