Uniting C1-Ammonium Enolates and Transition Metal Electrophiles via Cooperative Catalysis: The Direct Asymmetric α-Allylation of Aryl Acetic Acid Esters
作者:Kevin J. Schwarz、Jessica L. Amos、J. Cullen Klein、Dung T. Do、Thomas N. Snaddon
DOI:10.1021/jacs.6b01694
日期:2016.4.27
constitutes a significant challenge in the area of asymmetric catalysis, particularly where the configurational integrity of the products is problematic. Through the unprecedented merger of two independent, yet complementary, catalysis events it has been possible to facilitate the direct asymmetric α-allylation of readily available aryl aceticacid esters. Since enantioselection is determined by the nucleophile
Beyond azide–alkyne click reaction: easy access to 18F-labelled compounds via nitrile oxide cycloadditions
作者:Boris D. Zlatopolskiy、René Kandler、Diana Kobus、Felix M. Mottaghy、Bernd Neumaier
DOI:10.1039/c2cc31335a
日期:——
Radiofluorinated 4-fluorobenzonitrile oxide and N-hydroxy-4-fluorobenzimidoyl chloride rapidly react with different alkenes and alkynes under mild conditions. These cycloadditions are suitable for the preparation of low-molecular weight radiopharmaceuticals and, in a strain-promoted variant, can enable easy labelling of sensitive biopolymers.
divergent synthesis of β-lactams and α-aminoacidderivatives with isothiourea (ITU) catalysis by switching solvents was developed. The stereospecific Mannich reaction occurring between imine and C(1)-ammonium enolate generated zwitterionic intermediates, which underwent intramolecular lactamization and afforded β-lactam derivatives when DCM and CH3CN were used as solvents. However, when EtOH was used as