The first catalytic, asymmetric reactions of imines with homophthalic anhydride to form disubstituted 3,4-dihydroisoquinolones are reported. The use of N-mesyl aldimines is key, as more basic imines undergo rapid uncatalysed reactions, while imines possessing larger N-sulphonyl substituents form lactams with lower ee.
An anion‐binding approach to the problem of preparing enantioenriched γ‐lactams from enolisable anhydrides and imines is reported. A simple bisurea catalyst promotes the cycloaddition between α‐aryl succinic anhydrides and either PMP‐ or benzhydryl‐protected aldimines to provide γ‐lactams with two contiguous stereocentres (one quaternary) with complete diastereocontrol and high to excellent enantioselectivity for the first time. A DFT study has provided insight into the catalyst mode of action and the origins of the observed stereocontrol.
The first broad‐scope catalytic asymmetric Tamura cycloaddition reactions are reported. Under the influence of anion‐binding bifunctional catalysis a wide range of α,β‐unsaturated N‐trityl imines undergo reactions with enolisable anhydrides to form highly synthetically useful α‐tetralone structures with excellent enantio‐ and ‐diastereocontrol. In stark contrast to the previous literature benchmarks, doubly activated or highly electron deficient alkenes are not required. A facile two‐step, high yielding sequence can convert the cycloadducts to α‐haloketones (challenging to generate catalytically by other means) with the net formation of two new C−C bonds and three new contiguous stereocentres with exquisite stereocontrol. A DFT study has provided insight into the catalyst mode of action and the origins of the observed enantiocontrol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.