Imides trapping reagents

C.viii. Amines, Amides, Imides, and Sulfonamides as the H—Y Trapping Reagents Intermolecular Diene Dimerization... 

For example, Chang s group used simple amines [55], alcohols [56], and water [57] as trapping reagents to perform three-component reactions, obtaining amidates 86, imidates 87, and amides 88, respectively (Scheme 5.57). 

Recent advances include the use of new chiral bases, extention to substrates other than ketones, and trapping with electrophiles other than silylating reagents and aldehydes. Regarding alternate substrates and electrophiles, the Simpkins group reported alkylation of a prochiral diester with common alkyl halides with >98% ee [46]. Simpkins and coworkers have also demonstrated desym-metrization of cyclic imides, in this case with trapping by silyl groups [47]. 

Free cyclobutadiene has been detected in solution using an insoluble polymer-bound precursor, with trapping of the cyclobutadiene by a second polymer-bound reagent. As only a negligible fraction of the active polymer sites are at the surface of the solid, any reaction between the two solid phases requires the existence of an unbound intermediate. The cyclobutadiene precursor, a polymer-bound < -phenan-throline derivative of cyclobutadieneiron carbonyl (580) was oxidized in presence of a polymer-bound maleimide (581). The imide was then released from the polymer by treatment with methylamine. The reaction proceeds with 96% transfer of cyclobutadiene between the two polymers. 

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