64392-97-8Relevant academic research and scientific papers
Urea as a Redox-Active Directing Group under Asymmetric Photocatalysis of Iridium-Chiral Borate Ion Pairs
Uraguchi, Daisuke,Kimura, Yuto,Ueoka, Fumito,Ooi, Takashi
supporting information, p. 19462 - 19467 (2020/12/01)
The development of a photoinduced, highly diastereo- and enantioselective [3 + 2]-cycloaddition of N-cyclopropylurea with α-alkylstyrenes is reported. This asymmetric radical cycloaddition relies on the strategic placement of urea on cyclopropylamine as a redox-active directing group (DG) with anion-binding ability and the use of an ion pair, comprising an iridium polypyridyl complex and a weakly coordinating chiral borate ion, as a photocatalyst. The structure of the anion component of the catalyst governs reactivity, and pertinent structural modification of the borate ion enables high levels of catalytic activity and stereocontrol. This system tolerates a range of α-alkylstyrenes and hence offers rapid access to various aminocyclopentanes with contiguous tertiary and quaternary stereocenters, as the urea DG is readily removable.
Urea derivatives, process for making the same and herbicidal composition containing the same
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, (2008/06/13)
A urea derivative of the formula STR1 in which R is hydrogen, alkyl, alkenyl, cyanoalkyl or phenyl and R1 is STR2 X, if several, being the same or different and X being hydrogen, alkyl, alkoxy, halogenoalkyl, alkylthio, alkylsulfinyl, alkylsulf
