Geometry-Selective Synthesis of E or ZN-Vinyl Ureas (N-Carbamoyl Enamines)
摘要:
N-Vinyl ureas are emerging as a valuable class of compounds with both nucleophilic and electrophilic reactivity. They may be made by capturing the enamine tautomer of an imine with an isocyanate, a reaction which in general leads to the E isomer of the vinyl urea. Deprotonation of such a vinyl urea, or of an allyl urea, generates a dipole stabilized Z-allyl anion which may be protonated to return the Z-vinyl urea. Isomerization of an allyl urea with a Ru complex provides an alternative route to E-vinyl ureas.
One-Pot Transformation of Aldehydes to Ketones via Minisci-Type Reaction of Imines
作者:Zakhar M. Rubanov、Vitalij V. Levin、Alexander D. Dilman
DOI:10.1021/acs.orglett.3c03764
日期:2023.12.8
A method for the conversion of aldehydes to ketones via the preliminary formation of aldiminines is described. The imines are involved in acid promoted Minisci-type reaction with alkyl radicals generated fromesters of N-hydroxylphthalimide under photoredox conditions. Aminyl radical cations formed after the addition of the iminium ions are believed to be key intermediates, which determine the reaction